Inflation targeting and core inflation
Julie Smith
2005-01-01
This paper examines the interaction of core inflation and inflation targeting as a monetary policy regime. Interest in core inflation has grown because of inflation targeting. Core inflation is defined in numerous ways giving rise to many potential measures; this paper defines core inflation as the best forecaster of inflation. A cross-country study finds before the start of inflation targeting, but not after, core inflation differs between non-inflation targeters and inflation targeters. Thr...
Inflation and Inflation Uncertainty in Turkey
dogru, bulent
2014-01-01
Abstract: In this study, the relationship between inflation and inflation uncertainty is analyzed using Granger causality tests with annual inflation series covering the time period 1923 to 2012 for Turkish Economy. Inflation uncertainty is measured by Exponential Generalized Autoregressive Conditional Heteroskedastic model. Econometric findings suggest that although in long run the Friedman's hypothesis that high inflation increases inflation ...
LIU Jinquan; ZHENG Tingguo; SUI Jianli
2008-01-01
This paper uses the ARFIMA-FIGARCH model to investigate the China¡¯s monthly inflation rate from January 1983 to October 2005. It is found that both first moment and second moment of inflation have remarkable long memory, indicating the existence of long memory properties in both inflation level and inflation uncertainty. By the Granger-causality test on inflation rate and inflation uncertainty, it is shown that the inflation level affects the inflation uncertainty and so supports Friedman hy...
Inflation persistence in African countries: Does inflation targeting matter?
Phiri, Andrew
2016-01-01
This study investigates inflation persistence in annual CPI inflation collected between 1994 and 2014 for 46 African countries. We group these countries into panels according to whether they are inflation targeters or not and conduct estimations for pre and post inflation targeting periods. Interestingly enough, we find that inflation persistence was much higher for inflation targeters in periods before adopting their inflation targeting regimes and inflation persistence dropped by 40 percent...
Do inflation-linked bonds contain information about future inflation?
Directory of Open Access Journals (Sweden)
José Valentim Machado Vicente
2013-06-01
Full Text Available There is a widespread belief that inflation-linked bonds are a direct source of information about inflation expectations. In this paper we address this issue by analyzing the relationship between break-even inflation (the difference between nominal and real yields and future inflation. The dataset is extracted from Brazilian Treasury bonds covering the period from April 2005 to April 2011. We find that break-even inflation is an unbiased forecast only of the 3-month and 6-month ahead inflation. For medium horizons (12 and 18 months, break-even inflation has weak explanatory power of future inflation. Over long horizons (24 and 30 months, we report a significant, but counterintuitive, negative relationship between the break-even and realized inflation rates.
Inflation and Inflation Uncertainty Revisited: Evidence from Egypt
Directory of Open Access Journals (Sweden)
Mesbah Fathy Sharaf
2015-07-01
Full Text Available The welfare costs of inflation and inflation uncertainty are well documented in the literature and empirical evidence on the link between the two is sparse in the case of Egypt. This paper investigates the causal relationship between inflation and inflation uncertainty in Egypt using monthly time series data during the period January 1974–April 2015. To endogenously control for any potential structural breaks in the inflation time series, Zivot and Andrews (2002 and Clemente–Montanes–Reyes (1998 unit root tests are used. The inflation–inflation uncertainty relation is modeled by the standard two-step approach as well as simultaneously using various versions of the GARCH-M model to control for any potential feedback effects. The analyses explicitly control for the effect of the Economic Reform and Structural Adjustment Program (ERSAP undertaken by the Egyptian government in the early 1990s, which affected inflation rate and its associated volatility. Results show a high degree of inflation–volatility persistence in the response to inflationary shocks. Granger-causality test along with symmetric and asymmetric GARCH-M models indicate a statistically significant bi-directional positive relationship between inflation and inflation uncertainty, supporting both the Friedman–Ball and the Cukierman–Meltzer hypotheses. The findings are robust to the various estimation methods and model specifications. The findings of this paper support the view of adopting inflation-targeting policy in Egypt, after fulfilling its preconditions, to reduce the welfare cost of inflation and its related uncertainties. Monetary authorities in Egypt should enhance the credibility of monetary policy and attempt to reduce inflation uncertainty, which will help lower inflation rates.
International Nuclear Information System (INIS)
Halter, Sebastian
2012-01-01
This thesis is concerned with aspects of inflation both from a field theory and a string theory perspective. It aims at exploring new approaches to address the problem of moduli destabilization and the η-problem and to realize inflation in the matter sector. The first part is devoted to studying models of inflation in the framework of four-dimensional N=1 supergravity. We begin with investigating a new proposal to solve the problem of moduli destabilization, which seems to force us to choose between low-energy supersymmetry and high-scale inflation. This new approach is based on a particular way to couple the modulus to the F-term driving inflation. Using chaotic inflation with a shift symmetry as an example, we show that we can successfully combine low-energy supersymmetry and high-scale inflation. We construct a class of inflation models in N=1 supergravity where the inflaton resides in gauge non-singlet matter fields. These are extensions of a special class of hybrid inflation models, so-called tribrid inflation, where the η-problem can be solved by a Heisenberg symmetry. Compared to previously studied models, we have generalized our models with some inspiration from string theory. We investigate moduli stabilization during inflation and identify situations in which the inflaton slope is dominated by radiative corrections. We outline under which conditions this class of matter inflation models could be embedded into heterotic orbifold compactifications. In doing so, we suggest a new mechanism to stabilize some Kaehler moduli by F-terms for matter fields. In the second part, we consider models of warped D-brane inflation on a family of ten-dimensional supergravity backgrounds. We consider inflation along the radial direction near the tip of the warped throat and show that generically an inflection point arises for the inflaton potential, which is related to an inflection point of the dilaton profile. A universal scaling behaviour with the parameters of the
Energy Technology Data Exchange (ETDEWEB)
Halter, Sebastian
2012-07-09
This thesis is concerned with aspects of inflation both from a field theory and a string theory perspective. It aims at exploring new approaches to address the problem of moduli destabilization and the η-problem and to realize inflation in the matter sector. The first part is devoted to studying models of inflation in the framework of four-dimensional N=1 supergravity. We begin with investigating a new proposal to solve the problem of moduli destabilization, which seems to force us to choose between low-energy supersymmetry and high-scale inflation. This new approach is based on a particular way to couple the modulus to the F-term driving inflation. Using chaotic inflation with a shift symmetry as an example, we show that we can successfully combine low-energy supersymmetry and high-scale inflation. We construct a class of inflation models in N=1 supergravity where the inflaton resides in gauge non-singlet matter fields. These are extensions of a special class of hybrid inflation models, so-called tribrid inflation, where the η-problem can be solved by a Heisenberg symmetry. Compared to previously studied models, we have generalized our models with some inspiration from string theory. We investigate moduli stabilization during inflation and identify situations in which the inflaton slope is dominated by radiative corrections. We outline under which conditions this class of matter inflation models could be embedded into heterotic orbifold compactifications. In doing so, we suggest a new mechanism to stabilize some Kaehler moduli by F-terms for matter fields. In the second part, we consider models of warped D-brane inflation on a family of ten-dimensional supergravity backgrounds. We consider inflation along the radial direction near the tip of the warped throat and show that generically an inflection point arises for the inflaton potential, which is related to an inflection point of the dilaton profile. A universal scaling behaviour with the parameters of the
Inflation, its Volatility and the Inflation-Growth Tradeoff in India
Raghbendra Jha; Varsha S. Kulkarni
2013-01-01
This paper amends the New Keynesian Phillips curve model to include inflation volatility. It provides results on the determinants of inflation volatility and expected inflation volatility for OLS and ARDL(1,1) models and for change in inflation volatility and change in expected inflation volatility using ECM models. Output gap affects change in expected inflation volatility alone (in the ECM model) and not in the other models. Major determinants of inflation volatility and expected inflation ...
Towards a formal link between inflation perceptions and inflation ...
African Journals Online (AJOL)
This paper reports the finding of a survey of inflation perceptions and inflation expectations in South Africa undertaken in 2014. This survey posed questions on perceptions of past inflation (historic inflation) and expectations of future inflation to the same respondents and determined linkages between historic views and ...
Inflation Volatility and the Inflation-Growth Tradeoff in India
Raghbendra Jha; Varsha S. Kulkarni
2012-01-01
This paper amends the New Keynesian Phillips curve model to include inflation volatility and tests the determinants of such volatility for India. It provides results on the determinants of inflation volatility and expected inflation volatility for OLS and ARDL (1,1) models and for change in inflation volatility and change in expected inflation volatility using ECM models. Output gap affects change in expected inflation volatility along (in the ECM model) and not in the other models. Major det...
International Nuclear Information System (INIS)
Barenboim, Gabriela; Park, Wan-Il; Kinney, William H.
2016-01-01
We consider eternal inflation in hilltop-type inflation models, favored by current data, in which the scalar field in inflation rolls off of a local maximum of the potential. Unlike chaotic or plateau-type inflation models, in hilltop inflation the region of field space which supports eternal inflation is finite, and the expansion rate H EI during eternal inflation is almost exactly the same as the expansion rate H * during slow roll inflation. Therefore, in any given Hubble volume, there is a finite and calculable expectation value for the lifetime of the ''eternal'' inflation phase, during which quantum flucutations dominate over classical field evolution. We show that despite this, inflation in hilltop models is nonetheless eternal in the sense that the volume of the spacetime at any finite time is exponentially dominated by regions which continue to inflate. This is true regardless of the energy scale of inflation, and eternal inflation is supported for inflation at arbitrarily low energy scale.
Inflation, inflation uncertainty and output growth in the USA
Bhar, Ramprasad; Mallik, Girijasankar
2010-12-01
Employing a multivariate EGARCH-M model, this study investigates the effects of inflation uncertainty and growth uncertainty on inflation and output growth in the United States. Our results show that inflation uncertainty has a positive and significant effect on the level of inflation and a negative and significant effect on the output growth. However, output uncertainty has no significant effect on output growth or inflation. The oil price also has a positive and significant effect on inflation. These findings are robust and have been corroborated by use of an impulse response function. These results have important implications for inflation-targeting monetary policy, and the aim of stabilization policy in general.
INFLATE: INFlate Landing Apparatus Technology
Koryanov, V. V. K.; Da-Poian, V. D. P.
2018-02-01
Our project, named INFLATE (INFlatable Landing Apparatus Technology), aims at reducing space landing risks and constraints and so optimizing space missions (reducing cost, mass, and risk and in the same time improving performance).
Inflation Aversion and the Optimal Inflation Tax
Gaowang Wang; Heng-fu Zou
2011-01-01
The optimal inflation tax is reexamined in the framework of dynamic second best economy populated by individuals with inflation aversion. A simple formula for the optimal inflation rate is derived. Different from the literature, it is shown that if the marginal excess burden of other distorting taxes approaches zero, Friedman's rule for optimum quantity of money is not optimal, and the optimal inflation tax is negative; if the marginal excess burden of other taxes is nonzero, the optimal infl...
International Nuclear Information System (INIS)
Antusch, S.; King, F.S.; Malinsky, M.; Velasco-Sevilla, L.; Zavala, I.
2008-04-01
We propose an entirely new class of particle physics models of inflation based on the phase transition associated with the spontaneous breaking of family symmetry responsible for the generation of the effective quark and lepton Yukawa couplings. We show that the Higgs fields responsible for the breaking of family symmetry, called flavons, are natural candidates for the inflation field in new inflation, or the waterfall fields in hybrid inflation. This opens up a rich vein of possible inflation models, all linked to the physics of flavour, with interesting cosmological and phenomenological implications. Out of these many possibilities we discuss two examples which realise flavon inflation: a model of new inflation based on the discrete non-Abelian family symmetry group A 4 or Δ 27 , and a model of hybrid inflation embedded in an existing flavour model with a continuous SU(3) family symmetry. With the inflation scale and family symmetry breaking scale below the Grand Unification Theory (GUT) scale, these classes of models are free of the monopole (and similar) problems which are often associated with the GUT phase transition. (author)
Inflation perceptions and inflation expectation in South Africa: trends ...
African Journals Online (AJOL)
This paper reports the results of a multinomial analysis of inflation perceptions and inflation expectations in South Africa. Inflation perceptions surveys among South African individuals have been undertaken since 2006. The introduction of these surveys followed on domestic inflation expectation surveys conducted in 2000, ...
Inflation,Inflation Variability, and Output Performance. Venezuela 1951-2002
Olivo, Victor
2014-01-01
This paper explores the relationship between the level of inflation, inflation variability, and output performance in the Venezuelan economy for the period 1951-2002. The paper examines the mechanism through which higher inflation translates into lower non-oil real GDP growth. We find empirical evidence that supports Friedman's (1977) contention that higher inflation produces more inflation volatility /uncertainty that leads to relative price variability that in turn, is harmful for the prope...
Energy Technology Data Exchange (ETDEWEB)
Antusch, S. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, D-80805 Muenchen (Germany); King, S.F.; Malinsky, M. [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Velasco-Sevilla, L. [ICTP, Strada Costiera 11, Trieste 34014 (Italy)], E-mail: lvelasco@ictp.it; Zavala, I. [CPT and IPPP, Durham University, South Road, DH1 3LE, Durham (United Kingdom)
2008-08-14
We propose an entirely new class of particle physics models of inflation based on the phase transition associated with the spontaneous breaking of family symmetry responsible for the generation of the effective quark and lepton Yukawa couplings. We show that the Higgs fields responsible for the breaking of family symmetry, called flavons, are natural candidates for the inflaton field in new inflation, or the waterfall fields in hybrid inflation. This opens up a rich vein of possibilities for inflation, all linked to the physics of flavour, with interesting cosmological and phenomenological implications. Out of these, we discuss two examples which realise flavon inflation: a model of new inflation based on the discrete non-Abelian family symmetry group A{sub 4} or {delta}{sub 27}, and a model of hybrid inflation embedded in an existing flavour model with a continuous SU(3) family symmetry. With the inflation scale and family symmetry breaking scale below the Grand Unification Theory (GUT) scale, these classes of models are free of the monopole (and similar) problems which are often associated with the GUT phase transition.
International Nuclear Information System (INIS)
Antusch, S.; King, S.F.; Malinsky, M.; Velasco-Sevilla, L.; Zavala, I.
2008-01-01
We propose an entirely new class of particle physics models of inflation based on the phase transition associated with the spontaneous breaking of family symmetry responsible for the generation of the effective quark and lepton Yukawa couplings. We show that the Higgs fields responsible for the breaking of family symmetry, called flavons, are natural candidates for the inflaton field in new inflation, or the waterfall fields in hybrid inflation. This opens up a rich vein of possibilities for inflation, all linked to the physics of flavour, with interesting cosmological and phenomenological implications. Out of these, we discuss two examples which realise flavon inflation: a model of new inflation based on the discrete non-Abelian family symmetry group A 4 or Δ 27 , and a model of hybrid inflation embedded in an existing flavour model with a continuous SU(3) family symmetry. With the inflation scale and family symmetry breaking scale below the Grand Unification Theory (GUT) scale, these classes of models are free of the monopole (and similar) problems which are often associated with the GUT phase transition
Berkin, Andrew L.; Maeda, Kei-Ichi; Yokoyama, Junichi
1990-01-01
The cosmology resulting from two coupled scalar fields was studied, one which is either a new inflation or chaotic type inflation, and the other which has an exponentially decaying potential. Such a potential may appear in the conformally transformed frame of generalized Einstein theories like the Jordan-Brans-Dicke theory. The constraints necessary for successful inflation are examined. Conventional GUT models such as SU(5) were found to be compatible with new inflation, while restrictions on the self-coupling constant are significantly loosened for chaotic inflation.
Energy Technology Data Exchange (ETDEWEB)
Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kobayashi, Tsutomu [Kyoto Univ. (Japan). Hakubi Center; Kyoto Univ. (Japan). Dept. of Physics; Takahashi, Tomo [Saga Univ. (Japan). Dept. of Physics; Yamaguchi, Masahide [Tokyo Institute of Technology (Japan). Dept. of Physics; Yokoyama, Jun' ichi [Tokyo Univ. (JP). Research Center for the Early Universe (RESCEU); Tokyo Univ., Chiba (JP). Inst. for the Physics and Mathematics of the Universe (IPMU)
2012-03-15
We study Higgs inflation in the context of generalized G-inflation, i.e., the most general single-field inflation model with second-order field equations. The four variants of Higgs inflation proposed so far in the literature can be accommodated at one time in our framework. We also propose yet another class of Higgs inflation, the running Einstein inflation model, that can naturally arise from the generalized G-inflation framework. As a result, five Higgs inflation models in all should be discussed on an equal footing. Concise formulas for primordial fluctuations in these generalized Higgs inflation models are provided, which will be helpful to determine which model is favored from the future experiments and observations such as the Large Hadron Collider and the Planck satellite.
Gersbach, Hans; Hahn, Volker
2012-01-01
We introduce a new type of incentive contract for central bankers: inflation forecast contracts, which make central bankers’ remunerations contingent on the precision of their inflation forecasts. We show that such contracts enable central bankers to influence inflation expectations more effectively, thus facilitating more successful stabilization of current inflation. Inflation forecast contracts improve the accuracy of inflation forecasts, but have adverse consequences for output. On balanc...
International Nuclear Information System (INIS)
Liu, Yang; Piao, Yun-Song; Si, Zong-Guo
2009-01-01
In this paper, we revisit the idea of locked inflation, which does not require a potential satisfying the normal slow-roll condition, but suffers from the problems associated with ''saddle inflation''. We propose a scenario based on locked inflation, however, with an alternative evolution mechanism of the ''waterfall field'' φ. Instead of rolling down along the potential, the φ field will tunnel to end the inflation stage like in old inflation, by which the saddle inflation could be avoided. Further, we study a cascade of old locked inflation, which can be motivated by the string landscape. Our model is based on the consideration of making locked inflation feasible so as to give a working model without slow roll; It also can be seen as an effort to embed the old inflation in string landscape
International Nuclear Information System (INIS)
Kolb, E.W.
1991-01-01
In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been reviewed. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result if inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. (orig.)
International Nuclear Information System (INIS)
Kolb, E.W.; Chicago Univ., IL
1990-09-01
In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result in inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. 58 refs., 3 figs
Directory of Open Access Journals (Sweden)
Raphael T Mpofu
2017-03-01
Full Text Available The paper analyses the association between certain macroeconomic variables and food price inflation, non-food price inflation and overall inflation in Zimbabwe, and also seeks to determine the level of association between these variables, given food security implications and overall well-being of its citizens. The study reveals that during the 2010 to 2016 period, Zimbabwe experienced stable food prices—annual food price inflation for food and non-alcoholic beverages averaged a relatively low growth rate of 0.12% monthly, while non-food inflation monthly growth rate was 0.09% and overall inflation growth rate was 0.11%. Although inflation from 2010 had been declining, of late, the increase in annual inflation has been underpinned by a rise in non-food inflation. Zimbabwe’s annual inflation remains lower than inflation rates in other countries in the region. Despite the increases lately in overall inflation, it remained below zero in January 2016, mostly driven by the depreciation of the South African rand and declining international oil prices. It should also be noted that domestic demand continued to decline in 2015, leading to the observed decline in both food and non-food prices. While food inflation has remained relatively low, it should be noted that non-food expenditures is significant component of the household budget and the rising prices result often lead to declining purchasing power and force households to make difficult choices in terms of their purchases. The findings of the study are food inflation has a low association with the independent variables under study; Zimbabwe broad money supply, rand-dollar exchange rates and the South Africa food inflation. There is, however, a very strong association between non-food inflation and these independent variables, as well as between overall inflation and the independent variables. Given the mostly rural population and the high level of unemployment in Zimbabwe, it can be surmised that
Technical Note: Does Core Inflation Help Forecast Total Inflation? Evidence from Colombia
John Thornton
1998-01-01
In Colombia core and total inflation are both (1) series, and core inflation is cointegrated with total inflation. Granger causality tests using error correction methodology indicate that divergence of total inflation from core inflation is quickly revers
Euro area Inflation as a Predictor of National Inflation Rates
Antonella Cavallo; Antonio Ribba
2013-01-01
The stability of inflation differentials is an important condition for the smooth working of a currency area, such as the European Economic and Monetary Union. In the presence of stability, changes in national inflation rates, while holding Euro-area inflation fixed contemporaneously, should be only transitory. If this is the case, the rate of inflation of the whole area can also be interpreted as a predictor, at least in the long run, of the different national inflation rates. However, in th...
International Nuclear Information System (INIS)
Mishra, Hiranmaya; Mohanty, Subhendra; Nautiyal, Akhilesh
2013-01-01
In warm inflation models there is the requirement of generating large dissipative couplings of the inflation with radiation, while at the same Âătime, not de-stabilising the flatness of the inflation potential due to radiative corrections. One way to achieve this without fine tuning unrelated couplings is by supersymmetry. In this talk we will discuss warm inflation with Pseudo-Nambu-Goldstone Bosons (PNGB). In this case inflation and other light fields are PNGB. So, the radiative corrections to the potential are suppressed and the thermal Âăcorrections are small as long as the temperature is below the symmetry breaking scale. In such models it is possible to fulfill the contrary requirements of an inflation potential which is stable under radiative corrections and the generation of a large dissipative coupling of the inflation field with other light fields. This warm inflation model with PNGB gives the observed CMB-anisotropy amplitude and spectral index having the symmetry breaking scale at the GUT scale. (author)
International Nuclear Information System (INIS)
Murphy, P.J.
1987-01-01
The Theory of Inflation, namely, that at some point the entropy content of the universe was greatly increased, has much promise. It may solve the puzzles of homogeneity and the creation of structure. However, no particle physics model has yet been found that can successfully drive inflation. The difficulty in satisfying the constraint that the isotropy of the microwave background places on the effective potential of prospective models is immense. In this work we have codified the requirements of such models in a most general form. We have carefully calculated the amounts of inflation the various problems of the Standard Model need for their solution. We have derived a completely model independent upper bond on the inflationary Hubble parameter. We have developed a general notation with which to probe the possibilities of Multiple Inflation. We have shown that only in very unlikely circumstances will any evidence of an earlier inflation, survive the de Sitter period of its successor. In particular, it is demonstrated that it is most unlikely that two bouts of inflation will yield high amplitudes of density perturbations on small scales and low amplitudes on large. We conclude that, while multiple inflation will be of great theoretical interest, it is unlikely to have any observational impact
Remote inflation as hybrid-like sneutrino/MSSM inflation
International Nuclear Information System (INIS)
Matsuda, Tomohiro
2009-01-01
A new scenario of hybrid-like inflation is considered for sneutrino and MSSM fields. Contrary to the usual hybrid inflation model, the direct coupling between a trigger field and the sneutrino/MSSM inflaton field is not necessary for the scenario. The dissipation and the radiation from the sneutrino/MSSM inflaton can be written explicitly by using the Yukawa couplings. Remote inflation does not require the shift symmetry or cancellation in solving the η problem.
Pseudosmooth tribrid inflation
International Nuclear Information System (INIS)
Antusch, Stefan; Nolde, David; Rehman, Mansoor Ur
2012-01-01
We explore a new class of supersymmetric models of inflation where the inflaton is realised as a combination of a Higgs field and (gauge non-singlet) matter fields, using a ''tribrid'' structure of the superpotential. Inflation is associated with a phase transition around GUT scale energies. The inflationary trajectory already preselects the later vacuum after inflation, which has the advantage of automatically avoiding the production of dangerous topological defects at the end of inflation. While at first sight the models look similar to smooth inflation, they feature a waterfall and are therefore only pseudosmooth. The new class of models offers novel possibilities for realising inflation in close contact with particle physics, for instance with supersymmetric GUTs or with supersymmetric flavour models based on family symmetries
Pseudosmooth tribrid inflation
Antusch, Stefan; Nolde, David; Rehman, Mansoor Ur
2012-08-01
We explore a new class of supersymmetric models of inflation where the inflaton is realised as a combination of a Higgs field and (gauge non-singlet) matter fields, using a ``tribrid'' structure of the superpotential. Inflation is associated with a phase transition around GUT scale energies. The inflationary trajectory already preselects the later vacuum after inflation, which has the advantage of automatically avoiding the production of dangerous topological defects at the end of inflation. While at first sight the models look similar to smooth inflation, they feature a waterfall and are therefore only pseudosmooth. The new class of models offers novel possibilities for realising inflation in close contact with particle physics, for instance with supersymmetric GUTs or with supersymmetric flavour models based on family symmetries.
Inflation Protected Investment Strategies
Directory of Open Access Journals (Sweden)
Mirco Mahlstedt
2016-03-01
Full Text Available In this paper, a dynamic inflation-protected investment strategy is presented, which is based on traditional asset classes and Markov-switching models. Different stock market, as well as inflation regimes are identified, and within those regimes, the inflation hedging potential of stocks, bonds, real estate, commodities and gold are investigated. Within each regime, we determine optimal investment portfolios driven by the investment idea of protection from losses due to changing inflation if inflation is rising or high, but decoupling the performance from inflation if inflation is low. The results clearly indicate that these asset classes behave differently in different stock market and inflation regimes. Whereas in the long-run, we agree with the general opinion in the literature that stocks and bonds are a suitable hedge against inflation, we observe for short time horizons that the hedging potential of each asset class, especially of real estate and commodities, depend strongly on the state of the current market environment. Thus, our approach provides a possible explanation for different statements in the literature regarding the inflation hedging properties of these asset classes. A dynamic inflation-protected investment strategy is developed, which combines inflation protection and upside potential. This strategy outperforms standard buy-and-hold strategies, as well as the well-known 1 N -portfolio.
Pseudosmooth tribrid inflation
Energy Technology Data Exchange (ETDEWEB)
Antusch, Stefan; Nolde, David; Rehman, Mansoor Ur, E-mail: stefan.antusch@unibas.ch, E-mail: david.nolde@unibas.ch, E-mail: mansoor-ur.rehman@unibas.ch [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland)
2012-08-01
We explore a new class of supersymmetric models of inflation where the inflaton is realised as a combination of a Higgs field and (gauge non-singlet) matter fields, using a ''tribrid'' structure of the superpotential. Inflation is associated with a phase transition around GUT scale energies. The inflationary trajectory already preselects the later vacuum after inflation, which has the advantage of automatically avoiding the production of dangerous topological defects at the end of inflation. While at first sight the models look similar to smooth inflation, they feature a waterfall and are therefore only pseudosmooth. The new class of models offers novel possibilities for realising inflation in close contact with particle physics, for instance with supersymmetric GUTs or with supersymmetric flavour models based on family symmetries.
Is Inflation in India an Attractor of Inflation in Nepal?
Edimon Ginting
2007-01-01
The paper attempts to answer some important questions around the inflationary process in Nepal, particularly the transmission of inflation from India. Because the Nepali currency is pegged to the Indian rupee and the two countries share an open border, price developments in Nepal would be expected to mirror to those in India. The results show that inflation in India and inflation in Nepal tend to converge in the long run. Our estimates indicate that the passthrough of inflation from India to ...
Hebecker, Arthur; Lust, Dieter; Steinfurt, Stephan; Weigand, Timo
2012-01-01
As a first step towards inflation in genuinely F-theoretic setups, we propose a scenario where the inflaton is the relative position of two 7-branes on holomorphic 4-cycles. Non-supersymmetric gauge flux induces an attractive inter-brane potential. The latter is sufficiently flat in the supergravity regime of large volume moduli. Thus, in contrast to brane-antibrane inflation, fluxbrane inflation does not require warping. We calculate the inflaton potential both in the supergravity approximation and via an open-string one-loop computation on toroidal backgrounds. This leads us to propose a generalisation to genuine Calabi-Yau manifolds. We also comment on competing F-term effects. The end of inflation is marked by the condensation of tachyonic recombination fields between the 7-branes, triggering the formation of a bound state described as a stable extension along the 7-brane divisor. Hence our model fits in the framework of hybrid D-term inflation. We work out the main phenomenological properties of our D-te...
Estimating core inflation : the role of oil price shocks and imported inflation
Bjørnland, Hilde Christiane
1997-01-01
This paper calculates core inflation, by imposing long run restrictions on a structural vector autoregression (VAR) model containing the growth rate of output, inflation and oil prices. Core inflation is identified as that component in inflation that has no long run effect on output. No restrictions are placed on the response of output and inflation to the oil price shocks. The analysis is applied to Norway and the United Kingdom, both oil producing OECD countries. A model that ...
Eternal extended inflation and graceful exit from old inflation without Jordan-Brans-Dicke
International Nuclear Information System (INIS)
Linde, A.
1990-01-01
Recently a possible solution to the graceful exit problem of the old inflation was proposed in the context of the Jordan-Brans-Dicke theory (extended inflation). In this paper we will argue that inflation in this theory occurs in a most natural way if it starts near the Planck density, as in the standard version of chaotic inflation. With most natural initial conditions, the inflationary universe in the JBD theory enters the stage of permanent reproduction of new inflationary domains (eternal extended inflation). In order to realize the extended inflation scenario at least two classical scalar fields driving inflation are necessary, as distinct from the simplest versions of new and chaotic inflation. It is shown that in the theory of two scalar fields one can solve the graceful exit problem even without modifying the Einstein gravity theory, due to the possibility that the decay rate of the false vacuum in old inflation depends on the value of the second scalar field and hence on time. (orig.)
International Nuclear Information System (INIS)
Silk, J.; Turner, M.S.
1986-04-01
The Zel'dovich spectrum of adiabatic density perturbations is a generic prediction of inflation. There is increasing evidence that when the spectrum is normalized by observational data on small scales, there is not enough power on large scales to account for the observed large-scale structure in the Universe. Decoupling the spectrum on large and small scales could solve this problem. As a means of decoupling the large and small scales we propose double inflation (i.e., two episodes of inflation). In this scenario the spectrum on large scales is determined by the first episode of inflation and those on small scales by a second episode of inflation. We present three models for such a scenario. By nearly saturating the large angular-scale cosmic microwave anisotropy bound, we can easily account for the observed large-scale structure. We take the perturbations on small scales to be very large, deltarho/rho approx. = 0.1 to 0.01, which results in the production of primordial black holes (PBHs), early formation of structure, reionization of the Universe, and a rich array of astrophysical events. The Ω-problem is also addressed by our scenario. Allowing the density perturbations produced by the second episode of inflation to be large also lessens the fine-tuning required in the scalar potential and makes reheating much easier. We briefly speculate on the possibility that the second episode of inflation proceeds through the nucleation of bubbles, which today manifest themselves as empty bubbles whose surfaces are covered with galaxies. 37 refs., 1 fig
Inflation targeting and inflation performance : a comparative analysis
Samarina, Anna; De Haan, Jakob; Terpstra, M.
2014-01-01
This article examines how the impact of inflation targeting on inflation performance depends on the choice of country samples, adoption dates, time periods and methodological approaches. We apply two different estimation methods - difference-in-differences and propensity score matching - for our
Eternal extended inflation and graceful exit from old inflation without Jordan-Brans-Dicke
Linde, Andrei
1990-10-01
Recently a possible solution to the graceful exit problem of the old inflation was proposed in the context of the Jordan-Brans-Dicke theory (extended inflation). In this paper we will argue that inflation in this theory occurs in a most natural way if it starts near the Planck density, as in the standard version of chaotic inflation. With most natural initial conditions, the inflationary universe in the JBD theory enters the stage of permanent reproduction of new inflationary domains (eternal extended inflation). In order to realize the extended inflation scenario at least two classical scalar fields driving inflation are necessary, as distinct from the simplest versions of new and chaotic inflation. It is shown that in the theory of two scalar fields one can solve the graceful exit problem even without modifying the Einstein gravity theory, due to the possibility that the decay rate of the false rate vacuum in old inflation depends on the value of the second scalar field and hence on time. Address after 1 September 1990: Physics Department, Stanford University, Varian Building, Stanford, CA 94305, USA.
Quintessential inflation: A unified scenario of inflation and dark energy
Directory of Open Access Journals (Sweden)
Hossain Wali
2018-01-01
Full Text Available Quintessential inflation unifies inflation and late time acceleration by a single scalar field. Such a scenario, with canonical and non-canonical scalar fields, has been discussed. The scalar field behaves as an inflaton field during inflation and as a quintessence field during late time. Also the predictions of the models has been compared with the recent Planck data.
Kaehler-driven tribrid inflation
International Nuclear Information System (INIS)
Antusch, Stefan; Nolde, David
2012-01-01
We discuss a new class of tribrid inflation models in supergravity, where the shape of the inflaton potential is dominated by effects from the Kaehler potential. Tribrid inflation is a variant of hybrid inflation which is particularly suited for connecting inflation with particle physics, since the inflaton can be a D-flat combination of charged fields from the matter sector. In models of tribrid inflation studied so far, the inflaton potential was dominated by either loop corrections or by mixing effects with the waterfall field (as in 'pseudosmooth' tribrid inflation). Here we investigate the third possibility, namely that tribrid inflation is dominantly driven by effects from higher-dimensional operators of the Kaehler potential. We specify for which superpotential parameters the new regime is realized and show how it can be experimentally distinguished from the other two (loop-driven and p seudosmooth ) regimes
Towards inflation targeting in Egypt: the relationship between exchange rate and inflation
Directory of Open Access Journals (Sweden)
Aliaa Khodeir
2012-08-01
Full Text Available Since the Egyptian economy has recently moved towards inflation targeting, it became very important to know whether exchange rate movements have serious inflationary implications or not. To investigate this subject, the study aims to analyse the relevance of inflation with the exchange rate by using the Granger-causality test. Two indicators of inflation will be used, the consumer price index (CPI and wholesale price index (WPI. In general, the results show a strong relationship between the two variables in a way that may give support to the application of ‘flexible inflation targeting regime instead of strict inflation targeting regime’.
Energy Technology Data Exchange (ETDEWEB)
Burrage, Clare [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Rham, Claudia de [Univ. de Geneve (Switzerland). Dept. de Physique Theorique; Seery, David [Sussex Univ., Brigthon (United Kingdom). Dept. of Physics and Astronomy; Tolley, Andrew J. [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Physics
2010-09-15
Galileon inflation is a radiatively stable higher derivative model of inflation. The model is determined by a finite number of relevant operators which are protected by a covariant generalization of the Galileon shift symmetry. We show that the nongaussianity of the primordial density perturbation generated during an epoch of Galileon inflation is a particularly powerful observational probe of these models and that, when the speed of sound is small, f{sub NL} can be larger than the usual result f{sub NL} {proportional_to} C{sup -2}{sub s}. (orig.)
Inflation expectations and inflation uncertainty in the Eurozone : Evidence from survey data
Arnold, I.J.M.; Lemmen, J.J.G.
2006-01-01
This paper uses the European Commission's Consumer Survey to assess whether inflation expectations have converged and whether inflation uncertainty has diminished following the introduction of the Euro in Europe. Consumers' responses to the survey suggest that inflation expectations depend more on
Inflation expectations and inflation uncertainty in the eurozone : Evidence from survey data
Arnold, I.J.M.; Lemmen, J.J.G.
2008-01-01
This paper uses the European Commission’s Consumer Survey to assess whether inflation expectations have converged and whether inflation uncertainty has diminished following the introduction of the euro in Europe. Consumers’ responses to the survey suggest that inflation expectations depend more on
News on Inflation and the Epidemiology of Inflation Expectations
DEFF Research Database (Denmark)
Pfajfar, Damjan; Santoro, Emiliano
2013-01-01
This paper examines the nexus between news coverage on inflation and households’ inflation expectations. In doing so, we test the epidemiological foundations of the sticky information model (Carroll ). We use both aggregate and household-level data from the Survey Research Center at the University...... of Michigan. We highlight a fundamental disconnection among news on inflation, consumers’ frequency of expectation updating, and the accuracy of their expectations. Our evidence provides at best weak support to the epidemiological framework, as most of the consumers who update their expectations do not revise...
Retrofitting models of inflation
International Nuclear Information System (INIS)
Kain, Ben
2009-01-01
I use the method of retrofitting, developed by Dine, Feng and Silverstein, to generate the scale of inflation dynamically, allowing it to be naturally small. This is a general procedure that may be performed on existing models of supersymmetric inflation. I illustrate this idea on two such models, one an example of F-term inflation and the other an example of D-term inflation.
Scale-invariant extended inflation
International Nuclear Information System (INIS)
Holman, R.; Kolb, E.W.; Vadas, S.L.; Wang, Y.
1991-01-01
We propose a model of extended inflation which makes use of the nonlinear realization of scale invariance involving the dilaton coupled to an inflaton field whose potential admits a metastable ground state. The resulting theory resembles the Jordan-Brans-Dicke version of extended inflation. However, quantum effects, in the form of the conformal anomaly, generate a mass for the dilaton, thus allowing our model to evade the problems of the original version of extended inflation. We show that extended inflation can occur for a wide range of inflaton potentials with no fine-tuning of dimensionless parameters required. Furthermore, we also find that it is quite natural for the extended-inflation period to be followed by an epoch of slow-rollover inflation as the dilaton settles down to the minimum of its induced potential
News on Inflation and the Epidemiology of Inflation Expectations
Pfajfar, D.; Santoro, E.
2012-01-01
Abstract: This paper examines the nexus between news coverage on inflation and households' inflation expectations. In doing so, we test the epidemiological foundations of the sticky information model (Carroll, 2003, 2006). We use both aggregate and household-level data from the Survey Research
Attractors, universality, and inflation
Downes, Sean; Dutta, Bhaskar; Sinha, Kuver
2012-11-01
Studies of the initial conditions for inflation have conflicting predictions from exponential suppression to inevitability. At the level of phase space, this conflict arises from the competing intuitions of CPT invariance and thermodynamics. After reviewing this conflict, we enlarge the ensemble beyond phase space to include scalar potential data. We show how this leads to an important contribution from inflection point inflation, enhancing the likelihood of inflation to a power law, 1/Ne3. In the process, we emphasize the attractor dynamics of the gravity-scalar system and the existence of universality classes from inflection point inflation. Finally, we comment on the predictivity of inflation in light of these results.
News on inflation and the epidemiology of inflation expectations
Pfajfar, D.; Santoro, E.
2013-01-01
This paper examines the nexus between news coverage on inflation and households’ inflation expectations. In doing so, we test the epidemiological foundations of the sticky information model (Carroll 2003, 2006). We use both aggregate and household-level data from the Survey Research Center at the
García-Bellido, J; Montes, X; Garcia-Bellido, Juan; Garriga, Jaume; Montes, Xavier
1998-01-01
We show that a large class of two-field models of single-bubble open inflation do not lead to infinite open universes, as it was previously thought, but to an ensemble of very large but finite inflating `islands'. The reason is that the quantum tunneling responsible for the nucleation of the bubble does not occur simultaneously along both field directions and equal-time hypersurfaces in the open universe are not synchronized with equal-density or fixed-field hypersurfaces. The most probable tunneling trajectory corresponds to a zero value of the inflaton field; large values, necessary for the second period of inflation inside the bubble, only arise as localized fluctuations. The interior of each nucleated bubble will contain an infinite number of such inflating regions of comoving size of order $\\gamma^{-1}$, where $\\gamma$ depends on the parameters of the model. Each one of these islands will be a quasi-open universe. Since the volume of the hyperboloid is infinite, inflating islands with all possible values...
Directory of Open Access Journals (Sweden)
Jannie Rossouw
2011-08-01
Full Text Available This paper reports a comparison of South African household inflation expectations and inflation credibility surveys undertaken in 2006 and 2008. It tests for possible feed-through between inflation credibility and inflation expectations. It supplements earlier research that focused only on the 2006 survey results. The comparison shows that inflation expectations differed between different income groups in both 2006 and 2008. Inflation credibility differed between male and female respondents, but this difference did not feed through to inflation expectations. More periodic survey data will be required for developing final conclusions on the possibility of feed-through effects. To this end the structure of credibility surveys should be reconsidered, as a large percentage of respondents indicated that they ‘don’t know’ whether the historic rate of inflation is an accurate indication of price increases.
Does a Threshold Inflation Rate Exist? Quantile Inferences for Inflation and Its Variability
WenShwo Fang; Stephen M. Miller; Chih-Chuan Yeh
2009-01-01
Using quantile regressions and cross-sectional data from 152 countries, we examine the relationship between inflation and its variability. We consider two measures of inflation – the mean and median – and three different measures of inflation variability – the standard deviation, relative variation, and median deviation. All results from the mean and standard deviation, the mean and relative variation, or the median and the median deviation support both the hypothesis that higher inflation cr...
Nonminimally coupled hybrid inflation
International Nuclear Information System (INIS)
Koh, Seoktae; Minamitsuji, Masato
2011-01-01
We discuss the hybrid inflation model where the inflaton field is nonminimally coupled to gravity. In the Jordan frame, the potential contains φ 4 term as well as terms in the original hybrid inflation model. In our model, inflation can be classified into the type (I) and the type (II). In the type (I), inflation is terminated by the tachyonic instability of the waterfall field, while in the type (II) by the violation of slow-roll conditions. In our model, the reheating takes place only at the true minimum and even in the case (II) finally the tachyonic instability occurs after the termination of inflation. For a negative nonminimal coupling, inflation takes place in the vacuum-dominated region, in the large field region, or near the local minimum/maximum. Inflation in the vacuum-dominated region becomes either the type (I) or (II), resulting in a blue or red spectrum of the curvature perturbations, respectively. Inflation around the local maximum can be either the type (I) or the type (II), which results in the red spectrum of the curvature perturbations, while around the local minimum it must be the type (I), which results in the blue spectrum. In the large field region, to terminate inflation, potential in the Einstein frame must be positively tilted, always resulting in the red spectrum. We then numerically solve the equations of motion to investigate the whole dynamics of inflaton and confirm that the spectrum of curvature perturbations changes from red to blue ones as scales become smaller.
Kenneth H. Thomas
2000-01-01
Community Reinvestment Act of 1977 (CRA) ratings and performance evaluations are the only bank and thrift exam findings disclosed by financial institution regulators. Inflation of CRA ratings has been alleged by community activists for two decades, but there has been no quantification or empirical investigation of grade inflation. Using a unique grade inflation methodology on actual ratings and evaluation data for 1,407 small banks and thrifts under the revised CRA regulations, this paper con...
Assessing inflation persistence: micro evidence on an inflation targeting economy
Czech Academy of Sciences Publication Activity Database
Babecký, Jan; Coricelli, F.; Horváth, R.
-, č. 353 (2008), s. 1-37 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : inflation dynamics * persistence * inflation targeting Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp353.pdf
International Nuclear Information System (INIS)
Desroche, Mariel; Felder, Gary N.; Kratochvil, Jan M.; Linde, Andrei
2005-01-01
During the last ten years a detailed investigation of preheating was performed for chaotic inflation and for hybrid inflation. However, nonperturbative effects during reheating in the new inflation scenario remained practically unexplored. We investigate preheating in new inflation, using a combination of analytical and numerical methods. We find that the decay of the homogeneous component of the inflaton field and the resulting process of spontaneous symmetry breaking in the simplest models of new inflation usually occurs almost instantly: for the new inflation on the GUT scale it takes only about 5 oscillations of the field distribution. The decay of the homogeneous inflaton field is so efficient because of a combined effect of tachyonic preheating and parametric resonance. At that stage, the homogeneous oscillating inflaton field decays into a collection of waves of the inflaton field, with a typical wavelength of the order of the inverse inflaton mass. This stage usually is followed by a long stage of decay of the inflaton field into other particles, which can be described by the perturbative approach to reheating after inflation. The resulting reheating temperature typically is rather low
Inflation persistence and flexible prices
Robert Dittmar; William T. Gavin; Finn E. Kydland
2004-01-01
If the central bank follows an interest rate rule, then inflation is likely to be persistence, even when prices are fully flexible. Any shock, whether persistent or not, may lead to inflation persistence. In equilibrium, the dynamics of inflation are determined by the evolution of the spread between the real interest rate and the central bank’s target. Inflation persistence in U.S. data can be characterized by a vector autocorrelation function relating inflation and deviations of output from ...
Kadota, Kenji; Kobayashi, Tatsuo; Saga, Ikumi; Sumita, Keigo
2018-04-01
We propose a new model of single-field D-term inflation in supergravity, where the inflation is driven by a single modulus field which transforms non-linearly under the U(1) gauge symmetry. One of the notable features of our modulus D-term inflation scenario is that the global U(1) remains unbroken in the vacuum and hence our model is not plagued by the cosmic string problem which can exclude most of the conventional D-term inflation models proposed so far due to the CMB observations.
Racetrack inflation and cosmic strings
Energy Technology Data Exchange (ETDEWEB)
Brax, P. [CEA-Saclay, Gif sur Yvette (France). CEA/DSM/SPhT, Unite de Recherche Associee au CNRS, Service de Physique Theorique; Bruck, C. van de [Sheffield Univ. (United Kingdom). Dept. of Applied Mathematics; Davis, A.C.; Davis, S.C. [Cambridge Univ. (United Kingdom). DAMTP, Centre for Mathematical Sciences; Jeannerot, R. [Instituut-Lorentz for Theoretical Physics, Leiden (Netherlands); Postma, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[Nationaal Inst. voor Kernfysica en Hoge-Energiefysica (NIKHEF), Amsterdam (Netherlands)
2008-05-15
We consider the coupling of racetrack inflation to matter fields as realised in the D3/D7 brane system. In particular, we investigate the possibility of cosmic string formation in this system. We find that string formation before or at the onset of racetrack inflation is possible, but they are then inflated away. Furthermore, string formation at the end of inflation is prevented by the presence of the moduli sector. As a consequence, no strings survive racetrack inflation. (orig.)
Racetrack inflation and cosmic strings
International Nuclear Information System (INIS)
Brax, P.; Postma, M.
2008-05-01
We consider the coupling of racetrack inflation to matter fields as realised in the D3/D7 brane system. In particular, we investigate the possibility of cosmic string formation in this system. We find that string formation before or at the onset of racetrack inflation is possible, but they are then inflated away. Furthermore, string formation at the end of inflation is prevented by the presence of the moduli sector. As a consequence, no strings survive racetrack inflation. (orig.)
Kähler-driven tribrid inflation
Antusch, Stefan; Nolde, David
2012-11-01
We discuss a new class of tribrid inflation models in supergravity, where the shape of the inflaton potential is dominated by effects from the Kähler potential. Tribrid inflation is a variant of hybrid inflation which is particularly suited for connecting inflation with particle physics, since the inflaton can be a D-flat combination of charged fields from the matter sector. In models of tribrid inflation studied so far, the inflaton potential was dominated by either loop corrections or by mixing effects with the waterfall field (as in "pseudosmooth" tribrid inflation). Here we investigate the third possibility, namely that tribrid inflation is dominantly driven by effects from higher-dimensional operators of the Kähler potential. We specify for which superpotential parameters the new regime is realized and show how it can be experimentally distinguished from the other two (loop-driven and "pseudosmooth") regimes.
Inflation with Fayet-Iliopoulos terms
International Nuclear Information System (INIS)
Wieck, Clemens; Winkler, Martin Wolfgang
2014-08-01
Two of the most attractive realizations of inflation in supergravity are based upon the presence of a constant Fayet-Iliopoulos (FI) term. In D-term hybrid inflation it is the FI term itself which sets the energy scale of inflation. Alternatively, the breaking of a U(1) symmetry induced by the FI term can dynamically generate the quadratic potential of chaotic inflation. The purpose of this note is to study the possible UV embedding of these schemes in terms of the 'field-dependent FI term' related to a string modulus field which is stabilized by a non-perturbative superpotential. We find that in settings where the FI term drives inflation, gauge invariance prevents a decoupling of the modulus from the inflationary dynamics. The resulting inflation models generically contain additional dynamical degrees of freedom compared to D-term hybrid inflation. However, the dynamical realization of chaotic inflation can be obtained in complete analogy to the case of a constant FI term. We present a simple string-inspired toy model of this type.
Anisotropic inflation from charged scalar fields
International Nuclear Information System (INIS)
Emami, Razieh; Firouzjahi, Hassan; Movahed, S.M. Sadegh; Zarei, Moslem
2011-01-01
We consider models of inflation with U(1) gauge fields and charged scalar fields including symmetry breaking potential, chaotic inflation and hybrid inflation. We show that there exist attractor solutions where the anisotropies produced during inflation becomes comparable to the slow-roll parameters. In the models where the inflaton field is a charged scalar field the gauge field becomes highly oscillatory at the end of inflation ending inflation quickly. Furthermore, in charged hybrid inflation the onset of waterfall phase transition at the end of inflation is affected significantly by the evolution of the background gauge field. Rapid oscillations of the gauge field and its coupling to inflaton can have interesting effects on preheating and non-Gaussianities
Ellis, John; Garcia, Marcos A. G.; Nanopoulos, Dimitri V.; Olive, Keith A.
2016-05-01
Supersymmetry is the most natural framework for physics above the TeV scale, and the corresponding framework for early-Universe cosmology, including inflation, is supergravity. No-scale supergravity emerges from generic string compactifications and yields a non-negative potential, and is therefore a plausible framework for constructing models of inflation. No-scale inflation yields naturally predictions similar to those of the Starobinsky model based on R+{R}2 gravity, with a tilted spectrum of scalar perturbations: {n}s∼ 0.96, and small values of the tensor-to-scalar perturbation ratio r\\lt 0.1, as favoured by Planck and other data on the cosmic microwave background (CMB). Detailed measurements of the CMB may provide insights into the embedding of inflation within string theory as well as its links to collider physics.
Ellis, John; Nanopoulos, Dimitri V.; Olive, Keith A.
2016-01-01
Supersymmetry is the most natural framework for physics above the TeV scale, and the corresponding framework for early-Universe cosmology, including inflation, is supergravity. No-scale supergravity emerges from generic string compactifications and yields a non-negative potential, and is therefore a plausible framework for constructing models of inflation. No-scale inflation yields naturally predictions similar to those of the Starobinsky model based on $R + R^2$ gravity, with a tilted spectrum of scalar perturbations: $n_s \\sim 0.96$, and small values of the tensor-to-scalar perturbation ratio $r < 0.1$, as favoured by Planck and other data on the cosmic microwave background (CMB). Detailed measurements of the CMB may provide insights into the embedding of inflation within string theory as well as its links to collider physics.
Extended inflation with induced gravity
International Nuclear Information System (INIS)
Accetta, F.S.; Trester, J.J.; Department of Physics, Yale University, New Haven, Connecticut 06520)
1989-01-01
We consider a recently proposed extended model of inflation which improves upon the original old inflation scenario by achieving a graceful exit from the false-vacuum phase. In this paper extended inflation is generalized to include a potential V(phi) for the Brans-Dicke-type field phi. We find that whereas a graceful exit can still be had, the inclusion of a potential places constraints on the percolation time scale for exiting the inflationary phase. Additional constraints on V(phi) and the false-vacuum energy density rho /sub F/ from density and gravitational-wave perturbations are discussed. For initially small values of phi the false vacuum undergoes power-law inflation, while for initially large values of phi the expansion is exponential. Within true-vacuum regions slow-rolling inflation can occur. As a result, this model generically leads to multiple episodes of inflation. We discuss the significance these multiple episodes of inflation may have on the formation of large-scale structure and the production of voids
Inflation Rate Modelling in Indonesia
Directory of Open Access Journals (Sweden)
Rezzy Eko Caraka
2016-10-01
Full Text Available The purposes of this research were to analyse: (i Modelling the inflation rate in Indonesia with parametric regression. (ii Modelling the inflation rate in Indonesia using non-parametric regression spline multivariable (iii Determining the best model the inflation rate in Indonesia (iv Explaining the relationship inflation model parametric and non-parametric regression spline multivariable. Based on the analysis using the two methods mentioned the coefficient of determination (R2 in parametric regression of 65.1% while non-parametric amounted to 99.39%. To begin with, the factor of money supply or money stock, crude oil prices and the rupiah exchange rate against the dollar is significant on the rate of inflation. The stability of inflation is essential to support sustainable economic development and improve people's welfare. In conclusion, unstable inflation will complicate business planning business activities, both in production and investment activities as well as in the pricing of goods and services produced.DOI: 10.15408/etk.v15i2.3260
Quantum fluctuations and inflation
International Nuclear Information System (INIS)
Bardeen, J.M.; Bublik, G.J.
1986-05-01
We study the effect of quantum fluctuations on the roll-down rate of the inflation field in a semiclassical approximation; this is done by treating the inflation field as a classical random field. The quantum fluctuations are simulated by a noise term in the equation of motion. We consider two different inflationary scenarios (new and chaotic inflation) and find that the roll-down rate of the median value of the inflation field is increased by the quantum fluctuations. Non-linear effects may become important in the later stages of the inflationary regime. 8 refs., 2 figs
Quantum fluctuations and inflation
International Nuclear Information System (INIS)
Bardeen, J.M.; Bublik, G.J.
1987-01-01
The authors study the effect of quantum fluctuations on the roll-down rate of the inflation field in a semiclassical approximation; this is done by treating the inflation field as a classical random field. The quantum fluctuations are simulated by a noise term in the equation of motion. Two different inflationary scenarios (new and chaotic inflation) are considered and it is found that the roll-down rate of the median value of the inflation field is increased by the quantum fluctuations. Non-linear effects may become important in the later stages of the inflationary regime. (author)
Core inflation indicators for Saudi Arabia
Directory of Open Access Journals (Sweden)
Alkhareif Ryadh M.
2015-01-01
Full Text Available This paper constructs and analyzes core inflation indicators for Saudi Arabia for the period of March 2012 to May 2014 using two alternative approaches: the exclusion method (ex food and housing/rent and the statistical method. The findings of the analysis suggest that the ex food and housing/ rent inflation is more volatile than the overall CPI inflation over the sample period. In contrast, the statistical core inflation is relatively more stable and less volatile. Moreover, the ex food and housing/rent inflation is only weakly correlated with headline inflation, whereas the statistical core inflation exhibits a stronger correlation. This combination of lower volatility and higher correlation with headline inflation makes the statistical method a much better choice for policymakers. From a monetary policy standpoint, using a bundle of core inflation measures, including both properly constructed exclusion and statistical methods, is more desirable, especially when variation across measures is widespread, as is the case in Saudi Arabia.
What Drives China's Food-Price Inflation and How does It Affect the Aggregate Inflation?
Wenlang Zhang; Daniel Law
2010-01-01
It is typically argued that China's food-price inflation has been mainly driven by supply-side shocks including natural disasters. Our research, however, shows that demand pressures have played a more important role from a medium-term perspective. This suggests surging food prices may call for policy reactions even if non-food-price inflation is tame. Meanwhile, we find food-price inflation has not generated significant second-round effects on non-food-price inflation. In particular, while fo...
THE ACTUAL IMPLICATIONS OF INFLATION
Directory of Open Access Journals (Sweden)
Murăriţa Ilie
2011-12-01
Full Text Available The authors have started from the idea that inflationary phenomenon is a companion, the cause and the effect of the globalization of poverty in the broader context of world economy globalization. Therefore, starting from a common definition of inflation, the first objective was to identify causal relationships that singularize contemporary inflationary process. After that, attention was focused on the implications of inflation in the current stage, bearing in mind that monetary financial theory and practice are operating with perfectly anticipated inflation or imperfectly anticipated inflation. Inflation has great implications on the long-term contracts and wage contracts.
Alchemical inflation: inflaton turns into Higgs
Nakayama, Kazunori; Takahashi, Fuminobu
2012-11-01
We propose a new inflation model in which a gauge singlet inflaton turns into the Higgs condensate after inflation. The inflationary path is characterized by a moduli space of supersymmetric vacua spanned by the inflaton and Higgs field. The inflation energy scale is related to the soft supersymmetry breaking, and the Hubble parameter during inflation is smaller than the gravitino mass. The initial condition for the successful inflation is naturally realized by the pre-inflation in which the Higgs plays a role of the waterfall field.
Alchemical inflation: inflaton turns into Higgs
International Nuclear Information System (INIS)
Nakayama, Kazunori; Takahashi, Fuminobu
2012-01-01
We propose a new inflation model in which a gauge singlet inflaton turns into the Higgs condensate after inflation. The inflationary path is characterized by a moduli space of supersymmetric vacua spanned by the inflaton and Higgs field. The inflation energy scale is related to the soft supersymmetry breaking, and the Hubble parameter during inflation is smaller than the gravitino mass. The initial condition for the successful inflation is naturally realized by the pre-inflation in which the Higgs plays a role of the waterfall field
Heterogeneous inflation expectations and learning
Madeira, Carlos; Zafar, Basit
2012-01-01
Using the panel component of the Michigan Survey of Consumers, we estimate a learning model of inflation expectations, allowing for heterogeneous use of both private information and lifetime inflation experience. “Life-experience inflation” has a significant impact on individual expectations, but only for one-year-ahead inflation. Public information is substantially more relevant for longer-horizon expectations. Even controlling for life-experience inflation and public information, idiosyncra...
García-Bellido, J
1998-01-01
We propose a new model of inflation based on the soft-breaking of N=2 supersymmetric SU(2) Yang-Mills theory. The advantage of such a model is the fact that we can write an exact expression for the effective scalar potential, including non-perturbative effects, which preserves the analyticity and duality properties of the Seiberg-Witten solution. We find that the scalar condensate that plays the role of the inflaton can drive a long period of cosmological expansion, produce the right amount of temperature anisotropies in the microwave background, and end inflation when the monopole acquires a vacuum expectation value. Duality properties relate the weak coupling Higgs region where inflation takes place with the strong coupling monopole region, where reheating occurs, creating particles corresponding to the light degrees of freedom in the true vacuum.
International Nuclear Information System (INIS)
Vishniac, E.T.
1987-01-01
We examine the compatibility of inflation with the cosmic string theory for galaxy formation. There is a general conflict between having sufficient string tension to effect galaxy formation, and reheating after inflation to a high enough temperature that strings may form in a thermal phase transition. To escape this conflict, we propose a class of models where the inflation is coupled to the string-producing field. The strings are formed late in inflation as the inflaton rolls towards its zero-temperature value. A large subset of these models have a novel large-scale distribution of galaxies that is fractal, displays biasing without dynamics or feedback mechanisms, and contains voids. (orig.)
Dual-chamber inflatable oil boom
International Nuclear Information System (INIS)
Blair, R.M.; Tedeschi, E.T.
1993-01-01
An elongated floating material containment boom section is described having a normally vertical ballasted skirt depending from flotation means, and convertible from a flattened collapsed condition to a deployable condition wherein buoyancy chamber means extending along the upper edge of said skirt are inflated to expanded buoyant configuration, including: a gas-impervious sleeve extending along the upper edge of said normally vertical skirt forming a first outer collapsible and inflatable flotation chamber, a first inflation valve connecting the interior of said sleeve with the ambient atmosphere, through which gas under pressure may be introduced into said sleeve to inflate said first buoyant outer flotation chamber, elongated gas-impervious tube means positioned inside said outer flotation chamber and forming second collapsible and inflatable internal flotation bladder chamber means, second inflation valve means connecting the interior of said bladder means through said outer flotation chamber to the ambient atmosphere through which gas under pressure may be introduced into said bladder means to inflate it forming said second flotation chamber means inside said outer flotation chamber
Inflation targeting and the anchoring of inflation expectations in the CEE countries
Directory of Open Access Journals (Sweden)
Nedeljković Milan
2017-01-01
Full Text Available This paper studies the time evolution in the degree and level of anchoring of inflation expectations in four Central and Eastern European inflation targeting countries. The results suggest that the degree of anchoring of inflation expectations increased gradually in all countries over the last decade, while the level of implied inflation targets moved towards the official target. The extent of anchoring increased more strongly in the first years following the IT adoption and more gradually over the later period. We also find that smooth changes of the official target had a positive impact on anchoring. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 47028: Advancing Serbia’s Competitiveness in the Process of EU Accession
International Nuclear Information System (INIS)
Zavala, I.
2008-01-01
A new class of particle physics models of inflation based on the phase transition associated with the spontaneous breaking of family symmetry is proposed. The Higgs fields responsible for the breaking of family symmetry, the flavons, are natural inflaton candidates or waterfall fields in hybrid inflation. This opens up a rich vein of possible inflation models, all linked to the physics of flavour, with several interesting cosmological implications.
Topological defects in extended inflation
International Nuclear Information System (INIS)
Copeland, E.J.; Kolb, E.W.; Chicago Univ., IL; Liddle, A.R.
1990-04-01
We consider the production of topological defects, especially cosmic strings, in extended inflation models. In extended inflation, the Universe passes through a first-order phase transition via bubble percolation, which naturally allows defects to form at the end of inflation. The correlation length, which determines the number density of the defects, is related to the mean size of bubbles when they collide. This mechanism allows a natural combination of inflation and large-scale structure via cosmic strings. 18 refs
Topological defects in extended inflation
International Nuclear Information System (INIS)
Copeland, E.J.; Kolb, E.W.; Liddle, A.R.
1990-01-01
We consider the production of topological defects, especially cosmic strings, in extended-inflation models. In extended inflation, the Universe passes through a first-order phase transition via bubble percolation, which naturally allows defects to form at the end of inflation. The correlation length, which determines the number density of the defects, is related to the mean size of the bubbles when they collide. This mechanism allows a natural combination of inflation and large-scale structure via cosmic strings
Accidental inflation from Kaehler uplifting
International Nuclear Information System (INIS)
Ben-Dayan, Ido; Westphal, Alexander; Wieck, Clemens; Jing, Shenglin; Toronto Univ., ON
2013-09-01
We analyze the possibility of realizing inflation with a subsequent dS vacuum in the Kaehler uplifting scenario. The inclusion of several quantum corrections to the 4d effective action evades previous no-go theorems and allows for construction of simple and successful models of string inflation. The predictions of several benchmark models are in accord with current observations, i.e., a red spectral index, negligible non-gaussianity, and spectral distortions similar to the simplest models of inflation. A particularly interesting subclass of models are ''left-rolling'' ones, where the overall volume of the compactified dimensions shrinks during inflation. We call this phenomenon ''inflation by deflation'' (IBD), where deflation refers to the internal manifold. This subclass has the appealing features of being insensitive to initial conditions, avoiding the overshooting problem, and allowing for observable running α -5 . The latter results differ significantly from many string inflation models.
Giudice, Gian F
2011-01-01
We consider a simple extension of the Standard Model Higgs inflation with one new real scalar field which preserves unitarity up to the Planck scale. The new scalar field (called sigma) completes in the ultraviolet the theory of Higgs inflation by linearizing the Higgs kinetic term in the Einstein frame, just as the non-linear sigma model is unitarized into its linear version. The unitarity cutoff of the effective theory, obtained by integrating out the sigma field, varies with the background value of the Higgs field. In our setup, both the Higgs field and the sigma field participate in the inflationary dynamics, following the flat direction of the potential. We obtain the same slow-roll parameters and spectral index as in the original Higgs inflation but we find that the Hubble rate during inflation depends not only on the Higgs self-coupling, but also on the unknown couplings of the sigma field.
International Nuclear Information System (INIS)
Giudice, Gian F.; Lee, Hyun Min
2011-01-01
We consider a simple extension of the Standard Model Higgs inflation with one new real scalar field which preserves unitarity up to the Planck scale. The new scalar field (called sigma) completes in the ultraviolet the theory of Higgs inflation by linearizing the Higgs kinetic term in the Einstein frame, just as the non-linear sigma model is unitarized into its linear version. The unitarity cutoff of the effective theory, obtained by integrating out the sigma field, varies with the background value of the Higgs field. In our setup, both the Higgs field and the sigma field participate in the inflationary dynamics, following the flat direction of the potential. We obtain the same slow-roll parameters and spectral index as in the original Higgs inflation but we find that the Hubble rate during inflation depends not only on the Higgs self-coupling, but also on the unknown couplings of the sigma field.
Extended inflation with nonminimally coupled inflation field
International Nuclear Information System (INIS)
Panchapakesan, N.; Sethi, S.K.
1992-01-01
In this paper, an extended inflation model, in which the inflation field is nonminimally coupled to the gravity, is discussed. It is shown that the nucleation rate of bubbles, during a phase transition in the inflaton field, can increase as the transition proceeds for a wide range of parameters of the inflaton potential. The bounce action for three possible cases - the strong gravity regime, the thick-walled Coleman-DeLuccia bubbles and the thin-walled bubbles - is evaluated. The resulting bubble distribution for all the cases is shown to be in conformity with cosmological constraints for ω < 500
Tribrid Inflation in Supergravity
Antusch, Stefan; Dutta, Koushik; Kostka, Philipp M.
We propose a novel class of F-term hybrid inflation models in supergravity (SUGRA) where the η-problem is resolved using either a Heisenberg symmetry or a shift symmetry of the Kähler potential. In addition to the inflaton and the waterfall field, this class (referred to as tribrid inflation) contains a third "driving" field which contributes the large vacuum energy during inflation by its F-term. In contrast to the "standard" hybrid scenario, it has several attractive features due to the property of vanishing inflationary superpotential (Winf = 0) during inflation. Quantum corrections induced by symmetry breaking terms in the superpotential generate a slope of the potential and lead to a spectral tilt consistent with recent WMAP observations.
Stochastic effects in hybrid inflation
Martin, Jérôme; Vennin, Vincent
2012-02-01
Hybrid inflation is a two-field model where inflation ends due to an instability. In the neighborhood of the instability point, the potential is very flat and the quantum fluctuations dominate over the classical motion of the inflaton and waterfall fields. In this article, we study this regime in the framework of stochastic inflation. We numerically solve the two coupled Langevin equations controlling the evolution of the fields and compute the probability distributions of the total number of e-folds and of the inflation exit point. Then, we discuss the physical consequences of our results, in particular, the question of how the quantum diffusion can affect the observable predictions of hybrid inflation.
B. HEITZ
2005-01-01
This paper seeks to apply the general framework of Markov-switching models to inflation in France and in the USA. We propose a model where inflation can, alternatively, follow two regimes: the first one, where inflation is stationary, is interpreted as a situation where there exists a credible inflation target, even if it is not explicit; the second one where inflation is integrated. Moreover, observing that the two oil shocks were followed by accelerating inflation periods, we allow dependen...
Air-Inflated Fabric Structures
National Research Council Canada - National Science Library
Cavallaro, Paul V; Sadegh, Ali M
2006-01-01
.... Examples include air ships, weather balloons, inflatable antennas and radomes, temporary shelters, pneumatic muscles and actuators, inflatable boats, temporary bridging, and energy absorbers such as automotive air bags...
THE INFLATION IMPACT OF SELECTED EUROPEAN UNION MEMBERS ON POLISH INFLATION
Directory of Open Access Journals (Sweden)
Jarosław Czaja
2012-06-01
Full Text Available The article aims at determining the inflation influence between Poland and selected EU member states. Although for some time the general inflation level in those countries was definitely controllable, the problem seems to be returning. That is why in this article, using the model of Vector AutoRegression (VAR and Granger causality test, we are attempting to determine inflation influences on Poland. The study confirmed the impact of the selected countries on Polish inflation, expressed the general HICP index. However, in the case of Germany, the method has not proved the existence of such interactions. For this reason, it is made an attempt to clarify the reasons for non-compliance findings with data showing Germany as a Polish main trading partner for more than two decades. The authors try to show that lack of influence can be seen in the excessive generality of the main HICP index and predict that the chosen method confirm the effect of foreign trade indices in the HICP.
Changes in Inflation Dynamics under Inflation Targeting? Evidence from Central European Countries
Czech Academy of Sciences Publication Activity Database
Baxa, Jaromír; Plašil, M.; Vašíček, B.
2013-01-01
Roč. 11, č. 1 (2013), s. 2-5 ISSN 1803-7089 Institutional support: RVO:67985556 Keywords : Inflation Dynamics * Inflation Targeting? Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2013/E/baxa-0395372.pdf
Supersymmetric Majoron inflation
Energy Technology Data Exchange (ETDEWEB)
King, Stephen F.; Ludl, Patrick Otto [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom)
2017-03-31
We propose supersymmetric Majoron inflation in which the Majoron field Φ responsible for generating right-handed neutrino masses may also be suitable for giving low scale “hilltop” inflation, with a discrete lepton number ℤ{sub N} spontaneously broken at the end of inflation, while avoiding the domain wall problem. In the framework of non-minimal supergravity, we show that a successful spectral index can result with small running together with small tensor modes. We show that a range of heaviest right-handed neutrino masses can be generated, m{sub N}∼10{sup 1}−10{sup 16} GeV, consistent with the constraints from reheating and domain walls.
Pre-inflation physics and scalar perturbations
International Nuclear Information System (INIS)
Hirai, Shiro
2005-01-01
The effect of pre-inflation physics on the power spectrum of scalar perturbations is investigated. Considering various pre-inflation models with radiation-dominated or matter-dominated periods before inflation, the power spectra of curvature perturbations for large scales are calculated, and the spectral index and running spectral index are derived. It is shown that pre-inflation models in which the length of inflation is near 60 e-folds may reproduce some key properties implied by the Wilkinson microwave anisotropy probe data
IAS15 inflation adjustments and EVA: empirical evidence from a highly variable inflation regime
Directory of Open Access Journals (Sweden)
Pierre Erasmus
2011-08-01
Full Text Available Inflation can have a pronounced effect on the financial performance of a firm. This study makes inflation adjustments to a firm’s cost of sales, depreciation, level of gearing and assets in line with International Accounting Standard 15 (IAS15 in order to calculate an inflation-adjusted version of the economic value added (EVA measure. The study was conducted using data from South African industrial firms during a period characterised by highly variable inflation levels (1991-2005. The results indicate that during this period there were significant differences between the nominal and real values of the firms’ EVAs
Energy Technology Data Exchange (ETDEWEB)
Liu, Yang; Piao, Yun-Song [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Si, Zong-Guo, E-mail: liuyangbyf@mail.sdu.edu.cn, E-mail: yspiao@gucas.ac.cn, E-mail: zgsi@sdu.edu.cn [Department of Physics, Shandong University, Jinan 250100 (China)
2009-05-15
In this paper, we revisit the idea of locked inflation, which does not require a potential satisfying the normal slow-roll condition, but suffers from the problems associated with ''saddle inflation''. We propose a scenario based on locked inflation, however, with an alternative evolution mechanism of the ''waterfall field'' {phi}. Instead of rolling down along the potential, the {phi} field will tunnel to end the inflation stage like in old inflation, by which the saddle inflation could be avoided. Further, we study a cascade of old locked inflation, which can be motivated by the string landscape. Our model is based on the consideration of making locked inflation feasible so as to give a working model without slow roll; It also can be seen as an effort to embed the old inflation in string landscape.
Estimating Venezuelas Latent Inflation
Juan Carlos Bencomo; Hugo J. Montesinos; Hugo M. Montesinos; Jose Roberto Rondo
2011-01-01
Percent variation of the consumer price index (CPI) is the inflation indicator most widely used. This indicator, however, has some drawbacks. In addition to measurement errors of the CPI, there is a problem of incongruence between the definition of inflation as a sustained and generalized increase of prices and the traditional measure associated with the CPI. We use data from 1991 to 2005 to estimate a complementary indicator for Venezuela, the highest inflation country in Latin America. Late...
12 CFR 19.240 - Inflation adjustments.
2010-01-01
... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Inflation adjustments. 19.240 Section 19.240... PROCEDURE Civil Money Penalty Inflation Adjustments § 19.240 Inflation adjustments. (a) The maximum amount... Civil Penalties Inflation Adjustment Act of 1990 (28 U.S.C. 2461 note) as follows: ER10NO08.001 (b) The...
Mutated hilltop inflation revisited
Pal, Barun Kumar
2018-05-01
In this work we re-investigate pros and cons of mutated hilltop inflation. Applying Hamilton-Jacobi formalism we solve inflationary dynamics and find that inflation goes on along the {W}_{-1} branch of the Lambert function. Depending on the model parameter mutated hilltop model renders two types of inflationary solutions: one corresponds to small inflaton excursion during observable inflation and the other describes large field inflation. The inflationary observables from curvature perturbation are in tune with the current data for a wide range of the model parameter. The small field branch predicts negligible amount of tensor to scalar ratio r˜ O(10^{-4}), while the large field sector is capable of generating high amplitude for tensor perturbations, r˜ O(10^{-1}). Also, the spectral index is almost independent of the model parameter along with a very small negative amount of scalar running. Finally we find that the mutated hilltop inflation closely resembles the α -attractor class of inflationary models in the limit of α φ ≫ 1.
Is non-minimal inflation eternal?
International Nuclear Information System (INIS)
Feng, Chao-Jun; Li, Xin-Zhou
2010-01-01
The possibility that the non-minimal coupling inflation could be eternal is investigated. We calculate the quantum fluctuation of the inflaton in a Hubble time and find that it has the same value as that in the minimal case in the slow-roll limit. Armed with this result, we have studied some concrete non-minimal inflationary models including the chaotic inflation and the natural inflation, in which the inflaton is non-minimally coupled to the gravity. We find that the non-minimal coupling inflation could be eternal in some parameter spaces.
Energy Technology Data Exchange (ETDEWEB)
Freivogel, Ben; /Stanford U., Phys. Dept. /LBL, Berkeley; Hubeny, Veronika E.; /LBL, Berkeley /Durham U., Dept. of Math.; Maloney, Alexander; /Stanford U., Phys. Dept.; Myers, Rob; /Perimeter Inst. Theor. Phys. /Waterloo U.; Rangamani, Mukund; /LBL, Berkeley /Durham U., Dept. of Math.; Shenker, Stephen; /Stanford U., Phys. Dept.
2005-10-07
We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.
Chuss, David
2010-01-01
The Cosmic Microwave Background (CMB) has provided a wealth of information about the history and physics of the early Universe. Much progress has been made on uncovering the emerging Standard Model of Cosmology by such experiments as COBE and WMAP, and ESA's Planck Surveyor will likely increase our knowledge even more. Despite the success of this model, mysteries remain. Currently understood physics does not offer a compelling explanation for the homogeneity, flatness, and the origin of structure in the Universe. Cosmic Inflation, a brief epoch of exponential expansion, has been posted to explain these observations. If inflation is a reality, it is expected to produce a background spectrum of gravitational waves that will leave a small polarized imprint on the CMB. Discovery of this signal would give the first direct evidence for inflation and provide a window into physics at scales beyond those accessible to terrestrial particle accelerators. I will briefly review aspects of the Standard Model of Cosmology and discuss our current efforts to design and deploy experiments to measure the polarization of the CMB with the precision required to test inflation.
Inflation and quantum cosmology
International Nuclear Information System (INIS)
Linde, A.
1991-01-01
In this article a review of the present status of inflationary cosmology is given. We start with a discussion of the simplest version of the chaotic inflation scenario. Then we discuss some recent develoments in the inflationary cosmology, including the theory of a self-reproducing inflationary universe (eternal chaotic inflation). We do it with the help of stochastic approach to inflation. The results obtained within this approach are compared with the results obtained in the context of Euclidean quantum cosmology. (WL)
Coopersmith, Michael; Gambardella, Pascal J.
2016-01-01
This article is an extension of the work of one of us (Coopersmith, 2011) in deriving the relationship between certain interest rates and the inflation rate of a two component economic system. We use the well-known Fisher relation between the difference of the nominal interest rate and its inflation adjusted value to eliminate the inflation rate and obtain a delay differential equation. We provide computer simulated solutions for this equation over regimes of interest. This paper could be of ...
Microwave background anisotropies in quasiopen inflation
García-Bellido, Juan; Garriga, Jaume; Montes, Xavier
1999-10-01
Quasiopenness seems to be generic to multifield models of single-bubble open inflation. Instead of producing infinite open universes, these models actually produce an ensemble of very large but finite inflating islands. In this paper we study the possible constraints from CMB anisotropies on existing models of open inflation. The effect of supercurvature anisotropies combined with the quasiopenness of the inflating regions make some models incompatible with observations, and severely reduces the parameter space of others. Supernatural open inflation and the uncoupled two-field model seem to be ruled out due to these constraints for values of Ω0<~0.98. Others, such as the open hybrid inflation model with suitable parameters for the slow roll potential can be made compatible with observations.
Tribrid Inflation in Supergravity
International Nuclear Information System (INIS)
Antusch, Stefan; Dutta, Koushik; Kostka, Philipp M.
2010-01-01
We propose a novel class of F-term hybrid inflation models in supergravity (SUGRA) where the η-problem is resolved using either a Heisenberg symmetry or a shift symmetry of the Kaehler potential. In addition to the inflaton and the waterfall field, this class (referred to as tribrid inflation) contains a third 'driving' field which contributes the large vacuum energy during inflation by its F-term. In contrast to the 'standard' hybrid scenario, it has several attractive features due to the property of vanishing inflationary superpotential (W inf = 0) during inflation. While the symmetries of the Kaehler potential ensure a flat inflaton potential at tree-level, quantum corrections induced by symmetry breaking terms in the superpotential generate a slope of the potential and lead to a spectral tilt consistent with recent WMAP observations.
Accidental inflation from Kaehler uplifting
Energy Technology Data Exchange (ETDEWEB)
Ben-Dayan, Ido; Westphal, Alexander; Wieck, Clemens [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany). Theory Group; Jing, Shenglin [Toronto Univ., ON (Canada). Canadian Inst. for Theoretical Astrophysics; Toronto Univ., ON (Canada). Dept. of Astronomy and Astrophysics
2013-09-15
We analyze the possibility of realizing inflation with a subsequent dS vacuum in the Kaehler uplifting scenario. The inclusion of several quantum corrections to the 4d effective action evades previous no-go theorems and allows for construction of simple and successful models of string inflation. The predictions of several benchmark models are in accord with current observations, i.e., a red spectral index, negligible non-gaussianity, and spectral distortions similar to the simplest models of inflation. A particularly interesting subclass of models are ''left-rolling'' ones, where the overall volume of the compactified dimensions shrinks during inflation. We call this phenomenon ''inflation by deflation'' (IBD), where deflation refers to the internal manifold. This subclass has the appealing features of being insensitive to initial conditions, avoiding the overshooting problem, and allowing for observable running {alpha}<{proportional_to}0.012 and enhanced tensor-to-scalar ratio r{proportional_to}10{sup -5}. The latter results differ significantly from many string inflation models.
Initial conditions for chaotic inflation
International Nuclear Information System (INIS)
Brandenberger, R.; Kung, J.; Feldman, H.
1991-01-01
In contrast to many other inflationary Universe models, chaotic inflation does not depend on fine tuning initial conditions. Within the context of linear perturbation theory, it is shown that chaotic inflation is stable towards both metric and matter perturbations. Neglecting gravitational perturbations, it is shown that chaotic inflation is an attractor in initial condition space. (orig.)
International Nuclear Information System (INIS)
Davis, R.L.; Shellard, E.P.S.; Massachusetts Inst. of Tech., Cambridge
1989-01-01
Without inflation the energy density of relic axions in a Robertson-Walker universe arises not from coherent oscillations of a zero-momentum mode but from radiative decay of axion strings. An estimate of the upper bound on the PQ scale coming from these axions is in conflict with the lower bound from SN1987a. We present analytical and numerical evidence supporting this estimate. If true, then the axion needs inflation. With inflation the axion is safe, but the motivation for axion search experiments is weakened. (orig.)
Stability of compactification during inflation
International Nuclear Information System (INIS)
Amendola, L.; Litterio, M.; Occhionero, F.; Kolb, E.W.
1990-03-01
The possibility that inflation may trigger an instability in compactification of extra spatial dimensions is considered. In old, new, or extended inflation, the false vacuum energy results in a semiclassical instability in which the scalar field representing the radius of the extra dimensions may tunnel through a potential barrier leading to an expansion of the internal space. In chaotic inflation, if the initial value of the scalar field responsible for inflation is large enough, the internal space becomes classically unstable to ever increasing expansion. Restrictions on inflationary models necessary to keep the extra dimensions small are discussed. 15 refs., 5 figs
Higgs-Palatini inflation and unitarity
International Nuclear Information System (INIS)
Bauer, Florian; Demir, Durmus A.
2011-01-01
In the Higgs inflation scenario the Higgs field is strongly coupled to the Ricci scalar in order to drive primordial inflation. However, in its original form in pure metric formulation of gravity, the ultraviolet (UV) cutoff of the Higgs interactions and the Hubble rate are of the same magnitude, and this makes the whole inflationary evolution dependent of the unknown UV completion of the Higgs sector. This problem, the unitarity violation, plagues the Higgs inflation scenario. In this Letter we show that, in the Palatini formulation of gravitation, Higgs inflation does not suffer from unitarity violation since the UV cutoff lies parametrically much higher than the Hubble rate so that unknown UV physics does not disrupt the inflationary dynamics. Higgs-Palatini inflation, as we call it, is, therefore, UV-safe, minimal and endowed with predictive power.
Directory of Open Access Journals (Sweden)
Antipov Valerij Ivanovich
2015-10-01
Full Text Available The article gives a modern interpretation of the Fisher formula, the calculated velocity of circulation of money supply M2 in the interval 1995-2013 and forecast of its changes until 2030 when hypotheses about the rate of inflation and GDP. Points to the fallacy of its direct use to control inflation and money supply. For a more detailed understanding of the inflationary process proposes a new frequency formula and the explanation of the situation with the regulation of prices in the economy.
Assessing inflation persistence: micro evidence on an inflation targeting economy
Czech Academy of Sciences Publication Activity Database
Babecký, Jan; Coricelli, F.; Horváth, R.
2009-01-01
Roč. 59, č. 2 (2009), s. 102-127 ISSN 0015-1920 Grant - others:Česká národní banka(CZ) E5/05 Institutional research plan: CEZ:AV0Z70850503 Keywords : inflation dynamics * persistence * inflation targeting Subject RIV: AH - Economics Impact factor: 0.264, year: 2009 http://journal.fsv.cuni.cz/storage/1153_babeck%C3%BD_horv%C3%A1th_coricelli.pdf
Estimating the Threshold Level of Inflation for Thailand
Jiranyakul, Komain
2017-01-01
Abstract. This paper analyzes the relationship between inflation and economic growth in Thailand using annual dataset during 1990 and 2015. The threshold model is estimated for different levels of threshold inflation rate. The results suggest that the threshold level of inflation above which inflation significantly slow growth is estimated at 3 percent. The negative relationship between inflation and growth is apparent above this threshold level of inflation. In other words, the inflation rat...
Staggered multi-field inflation
International Nuclear Information System (INIS)
Battefeld, Diana; Battefeld, Thorsten; Davis, Anne-Christine
2008-01-01
We investigate multi-field inflationary scenarios with fields that drop out of the model in a staggered fashion. This feature is natural in certain multi-field inflationary setups within string theory; for instance, it can manifest itself when fields are related to tachyons that condense, or inter-brane distances that become meaningless when branes annihilate. Considering a separable potential, and promoting the number of fields to a smooth time dependent function, we derive the formalism to deal with these models at the background and perturbed level, providing general expressions for the scalar spectral index and the running. We recover known results of e.g. a dynamically relaxing cosmological constant in the appropriate limits. We further show that isocurvature perturbations are suppressed during inflation, and so perturbations are adiabatic and nearly Gaussian. The resulting setup might be interpreted as a novel type of warm inflation, readily implemented within string theory and without many of the shortcomings associated with warm inflation. To exemplify the applicability of the formalism we consider three concrete models: assisted inflation with exponential potentials as a simple toy model (a graceful exit becomes possible), inflation from multiple tachyons (a constant decay rate of the number of fields and negligible slow roll contributions turns out to be in good agreement with observations) and inflation from multiple M5-branes within M-theory (a narrow stacking of branes yields a consistent scenario)
Viorica, Daniela; Jemna, Danut; Pintilescu, Carmen; Asandului, Mircea
2014-01-01
The objective of this paper is to verify the hypotheses presented in the literature on the causal relationship between inflation and its uncertainty, for the newest EU countries. To ensure the robustness of the results, in the study four models for inflation uncertainty are estimated in parallel: ARCH (1), GARCH (1,1), EGARCH (1,1,1) and PARCH (1,1,1). The Granger method is used to test the causality between two variables. The working hypothesis is that groups of countries with a similar political and economic background in 1990 and are likely to be characterized by the same causal relationship between inflation and inflation uncertainty. Empirical results partially confirm this hypothesis. C22, E31, E37.
What is the Globalisation of Inflation?
Altansukh, Gantungalag; Becker, Ralf; Bratsiotis, George J.; Osborn, Denise R.
2017-01-01
This paper studies the globalisation of CPI inflation by analysing core, energy and food components, testing for structural breaks in the relationships between domestic inflation and a corresponding country-specific foreign inflation series at the monthly frequency for OECD countries.The iterative methodology employed separates coefficient and variance breaks, while also taking account of outliers. We find that the overall pattern of globalisation in aggregate inflation is largely driven by c...
Ferrara, Sergio
2017-01-01
Theories with elementary scalar degrees of freedom seem nowadays required for simple descriptions of the Standard Model and of the Early Universe. It is then natural to embed theories of inflation in supergravity, also in view of their possible ultraviolet completion in String Theory. After some general remarks on inflation in supergravity, we describe examples of minimal inflaton dynamics which are compatible with recent observations, including higher-curvature ones inspired by the Starobinsky model. We also discuss different scenarios for supersymmetry breaking during and after inflation, which include a revived role for non-linear realizations. In this spirit, we conclude with a discussion of the link, in four dimensions, between "brane supersymmetry breaking" and the super--Higgs effect in supergravity.
Warm inflation in the stochastic inflation formalism
International Nuclear Information System (INIS)
Silva, Leandro A. da; Ramos, Rudnei O.
2011-01-01
Full text: The basic assumption of stochastic inflation is the splitting, through the definition of a appropriate window function, of the quantum inflaton field in a long wavelength part (modes outside of the de Sitter horizon) and in a short wavelength (modes inside the de Sitter horizon) part. The inflationary mechanism then continuously shifts more and more modes of the bath field into the system stretching their physical wavelengths beyond the de Sitter horizon size, what generates an effective system-bath interaction. Therefore, the system field develops a stochastic dynamics driven by the bath field, that plays the role of noise source. The resulting equation of motion (EoM) is a Langevin-like equation. Applying this formalism to Warm Inflation scenario (where, alternatively to the cold inflation, we assume that the inflaton evolves in a thermal bath and through a dissipative process continuously generates radiation, thus avoiding the necessity of a reheating mechanism), we contrast the exact numerical solution of thermal power spectrum and two approximations currently used in the literature, and compare this to the quantum power spectrum at horizon crossing. Finally, we consider a more realistic model based on microscopic derivations to estimate the effects of non-Markovianity on the inflaton dynamics and on the thermal power spectrum. (author)
Primordial anisotropies in gauged hybrid inflation
Akbar Abolhasani, Ali; Emami, Razieh; Firouzjahi, Hassan
2014-05-01
We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a U(1)gauge field. Primordial anisotropies are generated either actively during inflation or from inhomogeneities modulating the surface of end of inflation during waterfall transition. We present a consistent δN mechanism to calculate the anisotropic power spectrum and bispectrum. We show that the primordial anisotropies generated at the surface of end of inflation do not depend on the number of e-folds and therefore do not produce dangerously large anisotropies associated with the IR modes. Furthermore, one can find the parameter space that the anisotropies generated from the surface of end of inflation cancel the anisotropies generated during inflation, therefore relaxing the constrains on model parameters imposed from IR anisotropies. We also show that the gauge field fluctuations induce a red-tilted power spectrum so the averaged power spectrum from the gauge field can change the total power spectrum from blue to red. Therefore, hybrid inflation, once gauged under a U(1) field, can be consistent with the cosmological observations.
Nonthermal gravitino production in tribrid inflation
Antusch, Stefan; Dutta, Koushik
2015-10-01
We investigate nonthermal gravitino production after tribrid inflation in supergravity, which is a variant of supersymmetric hybrid inflation where three fields are involved in the inflationary model and where the inflaton field resides in the matter sector of the theory. In contrast to conventional supersymmetric hybrid inflation, where nonthermal gravitino production imposes severe constraints on the inflationary model, we find that the "nonthermal gravitino problem" is generically absent in models of tribrid inflation, mainly due to two effects: (i) With the inflaton in tribrid inflation (after inflation) being lighter than the waterfall field, the latter has a second decay channel with a much larger rate than for the decay into gravitinos. This reduces the branching ratio for the decay of the waterfall field into gravitinos. (ii) The inflaton generically decays later than the waterfall field, and it does not produce gravitinos when it decays. This leads to a dilution of the gravitino population from the decays of the waterfall field. The combination of both effects generically leads to a strongly reduced gravitino production in tribrid inflation.
Primordial anisotropies in gauged hybrid inflation
International Nuclear Information System (INIS)
Abolhasani, Ali Akbar; Emami, Razieh; Firouzjahi, Hassan
2014-01-01
We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a U(1)gauge field. Primordial anisotropies are generated either actively during inflation or from inhomogeneities modulating the surface of end of inflation during waterfall transition. We present a consistent δN mechanism to calculate the anisotropic power spectrum and bispectrum. We show that the primordial anisotropies generated at the surface of end of inflation do not depend on the number of e-folds and therefore do not produce dangerously large anisotropies associated with the IR modes. Furthermore, one can find the parameter space that the anisotropies generated from the surface of end of inflation cancel the anisotropies generated during inflation, therefore relaxing the constrains on model parameters imposed from IR anisotropies. We also show that the gauge field fluctuations induce a red-tilted power spectrum so the averaged power spectrum from the gauge field can change the total power spectrum from blue to red. Therefore, hybrid inflation, once gauged under a U(1) field, can be consistent with the cosmological observations
Graceful exit from Higgs G-inflation
Energy Technology Data Exchange (ETDEWEB)
Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kobayashi, Tsutomu [Rikkyo Univ., Tokyo (Japan). Dept. of Physics; Kunimitsu, Taro [Tokyo Univ. (Japan). Dept. of Physics; Tokyo Univ. (Japan). Research Center for the Early Universe (RESCEU); Yamaguchi, Masahide [Tokyo Institute of Technology (Japan). Dept. of Physics; Yokoyama, Jun' ichi [Tokyo Univ. (Japan). Research Center for the Early Universe (RESCEU); Tokyo Univ., Chiba (Japan). Kavli Inst. for the Physics and Mathematics of the Universe (Kavli IPMU)
2013-09-15
Higgs G-inflation is a Higgs inflation model with a generalized Galileon term added to the standard model Higgs field, which realizes inflation compatible with observations. Recently, it was claimed that the generalized Galileon term induces instabilities during the oscillation phase, and that the simplest Higgs G-inflation model inevitably suffers from this problem. In this paper, we extend the original Higgs G-inflation Lagrangian to a more general form, namely introducing a higher-order kinetic term and generalizing the form of the Galileon term, so that the Higgs field can oscillate after inflation without encountering instabilities. Moreover, it accommodates a large region of the n{sub s}-r plane, most of which is consistent with current observations, leading us to expect the detection of B-mode polarization in the cosmic microwave background in the near future.
A smooth exit from eternal inflation?
Hawking, S. W.; Hertog, Thomas
2018-04-01
The usual theory of inflation breaks down in eternal inflation. We derive a dual description of eternal inflation in terms of a deformed Euclidean CFT located at the threshold of eternal inflation. The partition function gives the amplitude of different geometries of the threshold surface in the no-boundary state. Its local and global behavior in dual toy models shows that the amplitude is low for surfaces which are not nearly conformal to the round three-sphere and essentially zero for surfaces with negative curvature. Based on this we conjecture that the exit from eternal inflation does not produce an infinite fractal-like multiverse, but is finite and reasonably smooth.
Zvi Bodie
1989-01-01
A contract to insure $1 against inflation is equivalent to a European call option on the consumer price index. When there is no deductible this call option is equivalent to a forward contract on the CPI. Its price is the difference between the prices of a zero coupon real bond and a zero coupon nominal bond, both free of default risk. Provided that the risk-free real rate of interest is positive, the price of such an inflation insurance policy first rises and then falls with time to maturity....
A critical review of inflation
Turok, N G
2002-01-01
The theory of cosmic inflation offers an attractive resolution of some of the great paradoxes in cosmology: why the universe is so large, flat and uniform on large scales, and how density variations arose. Inflation has rightly dominated cosmological thinking for the past two decades, helping stimulate the development of high-precision observational programmes. The survival of simple inflationary models in the face of an impressive observational onslaught has been interpreted as convincing evidence of the correctness of the basic idea. In this paper, I review inflation, but highlight its weaknesses, explaining my reasons for believing that a more complete theory may supersede inflation without necessarily incorporating it.
A critical review of inflation
International Nuclear Information System (INIS)
Turok, Neil
2002-01-01
The theory of cosmic inflation offers an attractive resolution of some of the great paradoxes in cosmology: why the universe is so large, flat and uniform on large scales, and how density variations arose. Inflation has rightly dominated cosmological thinking for the past two decades, helping stimulate the development of high-precision observational programmes. The survival of simple inflationary models in the face of an impressive observational onslaught has been interpreted as convincing evidence of the correctness of the basic idea. In this paper, I review inflation, but highlight its weaknesses, explaining my reasons for believing that a more complete theory may supersede inflation without necessarily incorporating it
Inflation and the Higgs Scalar
Energy Technology Data Exchange (ETDEWEB)
Green, Dan [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
2014-12-05
This note makes a self-contained exposition of the basic facts of big bang cosmology as they relate to inflation. The fundamental problems with that model are then explored. A simple scalar model of inflation is evaluated which provides the solution of those problems and makes predictions which will soon be definitively tested. The possibility that the recently discovered fundamental Higgs scalar field drives inflation is explored.
How useful are leading indicators of inflation?
C. Alan Garner
1995-01-01
Many economists expect inflation to rise in 1995. These expectations are based on various approaches to forecasting inflation. One approach is based on the standard economic theory that inflation rises when slack is eliminated from the economy and production exceeds capacity constraints. According to this view, measures of economic slack such as unemployment and capacity utilization provide useful information about the inflation outlook. But the relationship between slack and inflation is com...
Ten years of inflation targeting in Serbia
Directory of Open Access Journals (Sweden)
Bungin Sanja
2017-01-01
Full Text Available Monetary strategy of inflation targeting in Serbia was unofficially introduced in September 2006. The National Bank of Serbia has faced the numerous challenges that are typical for transition countries which apply the same strategy. At the start of inflation targeting, inflation was reduced to a single-digit number, which characterises most other countries. However, the volatility of inflation during the implementation of the strategy has been extremely high, mainly caused by the changes of processed and unprocessed food prices. Moreover, for a country with a high degree of euroisation, such as Serbia, the exchange rate plays an important role in the movement of inflation. Controlling the trends of the exchange rate in order to maintain the stability of inflation is contrary to the assumptions of inflation targeting. However, it can be concluded that despite all the obstacles faced by the NBS, inflation targeting is the optimal choice of a monetary strategy.
The scale of inflation in the landscape
International Nuclear Information System (INIS)
Pedro, F.G.; Westphal, A.
2013-03-01
We determine the frequency of regions of small-field inflation in the Wigner landscape as an approximation to random supergravities/type IIB flux compactifications. We show that small-field inflation occurs exponentially more often than large-field inflation The power of primordial gravitational waves from inflation is generically tied to the scale of inflation. For small-field models this is below observational reach. However, we find small-field inflation to be dominated by the highest inflationary energy scales compatible with a sub-Planckian field range. Hence, we expect a typical tensor-to-scalar ratio r∝O(10 -3 ) currently undetectable in upcoming CMB measurements.
The scale of inflation in the landscape
Energy Technology Data Exchange (ETDEWEB)
Pedro, F.G.; Westphal, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group
2013-03-15
We determine the frequency of regions of small-field inflation in the Wigner landscape as an approximation to random supergravities/type IIB flux compactifications. We show that small-field inflation occurs exponentially more often than large-field inflation The power of primordial gravitational waves from inflation is generically tied to the scale of inflation. For small-field models this is below observational reach. However, we find small-field inflation to be dominated by the highest inflationary energy scales compatible with a sub-Planckian field range. Hence, we expect a typical tensor-to-scalar ratio r{proportional_to}O(10{sup -3}) currently undetectable in upcoming CMB measurements.
Vallurupalli, Srikanth; Kasula, Srikanth; Kumar Agarwal, Shiv; Pothineni, Naga Venkata K; Abualsuod, Amjad; Hakeem, Abdul; Ahmed, Zubair; Uretsky, Barry F
2017-08-01
High-pressure inflation for coronary stent deployment is universally performed. However, the duration of inflation is variable and does not take into account differences in lesion compliance. We developed a standardized "pressure optimization protocol" (POP) using inflation pressure stability rather than an arbitrary inflation time or angiographic balloon appearance for stent deployment. Whether this approach improves long-term outcomes is unknown. 792 patients who underwent PCI using either rapid inflation/deflation (n = 376) or POP (n = 416) between January 2009 and March 2014 were included. Exclusion criteria included PCI for acute myocardial infarction, in-stent restenosis, chronic total occlusion, left main, and saphenous vein graft lesions. Primary endpoint was target vessel failure [TVF = combined end point of target vessel revascularization (TVR), myocardial infarction, and cardiac death]. Outcomes were analyzed in the entire cohort and in a propensity analysis. Stent implantation using POP with a median follow-up of 1317 days was associated with lower TVF compared with rapid inflation/deflation (10.1 vs. 17.8%, P inflation/deflation (10 vs. 18%, P < 0.0001). Stent deployment using POP led to reduced TVF compared to rapid I/D. These results recommend this method to improve long-term outcomes. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Inflation experiences of retirees
Kalwij, Adriaan; Alessie, Robertus; Gardner, Jonathan; Ali, Ashik Anwar
The inflation experience of people depends on their expenditure patterns and price developments. This paper identifies groups of retirees that have experienced relatively high price inflation over the last few decades and could thus be considered most vulnerable when income decreases, as has been
Affleck-Dine baryogenesis just after inflation
International Nuclear Information System (INIS)
Yamada, Masaki
2015-11-01
We propose a new scenario of Affleck-Dine baryogenesis where a at direction in the MSSM generates B-L asymmetry just after the end of inflation. The resulting amount of baryon asymmetry is independent of low-energy supersymmetric models but is dependent on inflation models. We consider the hybrid and chaotic inflation models and find that reheating temperature is required to be higher than that in the conventional scenario of Affleck-Dine baryogenesis. In particular, non-thermal gravitino-overproduction problem is naturally avoided in the hybrid inflation model. Our results imply that Affleck-Dine baryogenesis can be realized in a broader range of supersymmetry and inflation models than expected in the literature.
International Nuclear Information System (INIS)
Croon, Djuna; Sanz, Verónica; Setford, Jack
2015-01-01
Identifying the inflaton with a pseudo-Goldstone boson explains the flatness of its potential. Successful Goldstone Inflation should also be robust against UV corrections, such as from quantum gravity: in the language of the effective field theory this implies that all scales are sub-Planckian. In this paper we present scenarios which realise both requirements by examining the structure of Goldstone potentials arising from Coleman-Weinberg contributions. We focus on single-field models, for which we notice that both bosonic and fermionic contributions are required and that spinorial fermion representations can generate the right potential shape. We then evaluate the constraints on non-Gaussianity from higher-derivative interactions, finding that axiomatic constraints on Goldstone boson scattering prevail over the current CMB measurements. The fit to CMB data can be connected to the UV completions for Goldstone Inflation, finding relations in the spectrum of new resonances. Finally, we show how hybrid inflation can be realised in the same context, where both the inflaton and the waterfall fields share a common origin as Goldstones.
Energy Technology Data Exchange (ETDEWEB)
Croon, Djuna; Sanz, Verónica; Setford, Jack [Department of Physics and Astronomy, University of Sussex,Brighton BN1 9QH (United Kingdom)
2015-10-05
Identifying the inflaton with a pseudo-Goldstone boson explains the flatness of its potential. Successful Goldstone Inflation should also be robust against UV corrections, such as from quantum gravity: in the language of the effective field theory this implies that all scales are sub-Planckian. In this paper we present scenarios which realise both requirements by examining the structure of Goldstone potentials arising from Coleman-Weinberg contributions. We focus on single-field models, for which we notice that both bosonic and fermionic contributions are required and that spinorial fermion representations can generate the right potential shape. We then evaluate the constraints on non-Gaussianity from higher-derivative interactions, finding that axiomatic constraints on Goldstone boson scattering prevail over the current CMB measurements. The fit to CMB data can be connected to the UV completions for Goldstone Inflation, finding relations in the spectrum of new resonances. Finally, we show how hybrid inflation can be realised in the same context, where both the inflaton and the waterfall fields share a common origin as Goldstones.
Croon, Djuna; Sanz, Verónica; Setford, Jack
2015-10-01
Identifying the inflaton with a pseudo-Goldstone boson explains the flatness of its potential. Successful Goldstone Inflation should also be robust against UV corrections, such as from quantum gravity: in the language of the effective field theory this implies that all scales are sub-Planckian. In this paper we present scenarios which realise both requirements by examining the structure of Goldstone potentials arising from Coleman-Weinberg contributions. We focus on single-field models, for which we notice that both bosonic and fermionic contributions are required and that spinorial fermion representations can generate the right potential shape. We then evaluate the constraints on non-Gaussianity from higher-derivative interactions, finding that axiomatic constraints on Goldstone boson scattering prevail over the current CMB measurements. The fit to CMB data can be connected to the UV completions for Goldstone Inflation, finding relations in the spectrum of new resonances. Finally, we show how hybrid inflation can be realised in the same context, where both the inflaton and the waterfall fields share a common origin as Goldstones.
Dark energy from gravitoelectromagnetic inflation?
International Nuclear Information System (INIS)
Membiela, A.; Bellini, M.
2008-01-01
Gravitoelectromagnetic Inflation (GI) was introduced to describe in a unified manner electromagnetic, gravitatory and inflation fields from a 5D vacuum state. On the other hand, the primordial origin and evolution of dark energy is today unknown. In this letter we show using GI that the zero modes of some redefined vector fields B i = A i /a produced during inflation could be the source of dark energy in the Universe.
Inflation and Failure of Polymeric Membranes
DEFF Research Database (Denmark)
Hassager, Ole; Neergaard, Jesper
2000-01-01
We consider the inflation of an axisymmetric polymeric membrane.Some membranes composed of viscoelastic materialsdescribed by a Mooney-Rivlin model show a monotone increasingpressure during inflation. These materialsdevelop a homogeneous membrane thickness in agreement with the Considere...... is found to stabilize the inflated polymer membrane....
Anisotropic inflation reexamined: upper bound on broken rotational invariance during inflation
International Nuclear Information System (INIS)
Naruko, Atsushi; Yamaguchi, Masahide; Komatsu, Eiichiro
2015-01-01
The presence of a light vector field coupled to a scalar field during inflation makes a distinct prediction: the observed correlation functions of the cosmic microwave background (CMB) become statistically anisotropic. We study the implications of the current bound on statistical anisotropy derived from the Planck 2013 CMB temperature data for such a model. The previous calculations based on the attractor solution indicate that the magnitude of anisotropy in the power spectrum is proportional to N 2 , where N is the number of e-folds of inflation counted from the end of inflation. In this paper, we show that the attractor solution is not necessarily compatible with the current bound, and derive new predictions using another branch of anisotropic inflation. In addition, we improve upon the calculation of the mode function of perturbations by including the leading-order slow-roll corrections. We find that the anisotropy is roughly proportional to [2(ε H +4η H )/3−4(c−1)] −2 , where ε H and η H are the usual slow-roll parameters and c is the parameter in the model, regardless of the form of potential of an inflaton field. The bound from Planck implies that breaking of rotational invariance during inflation (characterized by the background homogeneous shear divided by the Hubble rate) is limited to be less than O(10 −9 ). This bound is many orders of magnitude smaller than the amplitude of breaking of time translation invariance, which is observed to be O(10 −2 )
Linear inflation from quartic potential
Energy Technology Data Exchange (ETDEWEB)
Kannike, Kristjan; Racioppi, Antonio [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Raidal, Martti [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Institute of Physics, University of Tartu,Tartu (Estonia)
2016-01-07
We show that if the inflaton has a non-minimal coupling to gravity and the Planck scale is dynamically generated, the results of Coleman-Weinberg inflation are confined in between two attractor solutions: quadratic inflation, which is ruled out by the recent measurements, and linear inflation which, instead, is in the experimental allowed region. The minimal scenario has only one free parameter — the inflaton’s non-minimal coupling to gravity — that determines all physical parameters such as the tensor-to-scalar ratio and the reheating temperature of the Universe. Should the more precise future measurements of inflationary parameters point towards linear inflation, further interest in scale-invariant scenarios would be motivated.
Optimal inflation for the U.S.
Roberto M. Billi
2007-01-01
What is the correctly measured inflation rate that monetary policy should aim for in the long-run? This paper characterizes the optimal inflation rate for the U.S. economy in a New Keynesian sticky-price model with an occasionally binding zero lower bound on the nominal interest rate. Real-rate and mark-up shocks jointly determine the optimal inflation rate to be positive but not large. Even allowing for the possibility of extreme model misspecification, the optimal inflation rate is robustly...
Winitzki, Sergei
2009-01-01
This volume is the only monograph covering the exciting and dazzling recent developments in quantum cosmology, including the theory of the "multiverse" and eternal inflation pioneered by A Vilenkin, A Linde, S W Hawking, and others. Written by a leading expert in the field known for his depth and clarity of presentation, the volume presents an overview of 20 years of development of the theory of eternal inflation as well as a comprehensive, research-level introduction into the current methods and problems. This volume is invaluable for researchers as a definitive reference in the rapidly devel
Cointegration Approach to Analysing Inflation in Croatia
Directory of Open Access Journals (Sweden)
Lena Malešević-Perović
2009-06-01
Full Text Available The aim of this paper is to analyse the determinants of inflation in Croatia in the period 1994:6-2006:6. We use a cointegration approach and find that increases in wages positively influence inflation in the long-run. Furthermore, in the period from June 1994 onward, the depreciation of the currency also contributed to inflation. Money does not explain Croatian inflation. This irrelevance of the money supply is consistent with its endogeneity to exchange rate targeting, whereby the money supply is determined by developments in the foreign exchange market. The value of inflation in the previous period is also found to be significant, thus indicating some inflation inertia.
Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.
2013-07-01
The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic
2010-10-01
... Inspections § 169.849 Posting placards containing instructions for launching and inflating inflatable... accessible to the ship's company and guests approved placards containing instructions for launching and... determined by the Officer in Charge, Marine Inspection. ...
International Nuclear Information System (INIS)
Antusch, Stefan
2006-01-01
We review the scenario of sneutrino hybrid inflation, where one of the singlet sneutrinos, the superpartners of the right-handed neutrinos, plays the role of the inflaton. In a minimal model of sneutrino hybrid inflation, the spectral index is given by ns ≅ 1 + 2γ. With γ = 0.025 ± 0.01 constrained by WMAP, a running spectral index vertical bar dns/dlnk vertical bar << vertical barγvertical bar and a tensor-to-scalar ratio r << γ2 are predicted. Small neutrino masses arise from the seesaw mechanism, with heavy masses for the singlet (s)neutrinos generated by the vacuum expectation value of the waterfall field after inflation. The baryon asymmetry of the universe can be explained by non-thermal leptogenesis via sneutrino inflaton decay, with low reheat temperature TRH ≅ 106 GeV
12 CFR 1780.80 - Inflation adjustments.
2010-01-01
... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Inflation adjustments. 1780.80 Section 1780.80... DEVELOPMENT RULES OF PRACTICE AND PROCEDURE RULES OF PRACTICE AND PROCEDURE Civil Money Penalty Inflation Adjustments § 1780.80 Inflation adjustments. The maximum amount of each civil money penalty within OFHEO's...
Curvaton and the inhomogeneous end of inflation
International Nuclear Information System (INIS)
Assadullahi, Hooshyar; Wands, David; Firouzjahi, Hassan; Namjoo, Mohammad Hossein
2012-01-01
We study the primordial density perturbations and non-Gaussianities generated from the combined effects of an inhomogeneous end of inflation and curvaton decay in hybrid inflation. This dual role is played by a single isocurvature field which is massless during inflation but acquire a mass at the end of inflation via the waterfall phase transition. We calculate the resulting primordial non-Gaussianity characterized by the non-linearity parameter, f NL , recovering the usual end-of-inflation result when the field decays promptly and the usual curvaton result if the field decays sufficiently late
Scalar-tensor linear inflation
Energy Technology Data Exchange (ETDEWEB)
Artymowski, Michał [Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków (Poland); Racioppi, Antonio, E-mail: Michal.Artymowski@uj.edu.pl, E-mail: Antonio.Racioppi@kbfi.ee [National Institute of Chemical Physics and Biophysics, Rävala 10, 10143 Tallinn (Estonia)
2017-04-01
We investigate two approaches to non-minimally coupled gravity theories which present linear inflation as attractor solution: a) the scalar-tensor theory approach, where we look for a scalar-tensor theory that would restore results of linear inflation in the strong coupling limit for a non-minimal coupling to gravity of the form of f (φ) R /2; b) the particle physics approach, where we motivate the form of the Jordan frame potential by loop corrections to the inflaton field. In both cases the Jordan frame potentials are modifications of the induced gravity inflationary scenario, but instead of the Starobinsky attractor they lead to linear inflation in the strong coupling limit.
Luis F. Zegarra; Eduardo MorÃ³n
1999-01-01
A central element of an inflation targeting approach to monetary policy is a proper measure of inflation. The international evidence suggests the use of core inflation measures. In this paper we claim that core inflation should be measured as the underlying trend of inflation that comes from nominal shocks that have no real effect in the long term. However, most of the time core inflation is computed zero weighting observations at the tail of the inflation distribution. Quah and Vahey (1996) ...
The properties of inflation expectations: Evidence for India
Directory of Open Access Journals (Sweden)
Naresh Kumar Sharma
2018-01-01
Full Text Available Empirical inferences about particular forms of agents’ inflation expectations are crucial for the conduct of monetary policy. This paper is an attempt to explore the properties of the Reserve Bank of India’s survey data of households’ inflation expectations. The paper shows that survey respondents do not form expectations rationally, regardless of the reference measures of inflation used. Further, results indicate that inflation expectations are formed purely in backward-looking manner, suggesting that the Reserve Bank of India (RBI has a low degree of credibility within the survey respondents. The study then formulates a model to identify individual elements of the backward-looking expectations in the data. The results suggest that the respondents’ short term expectations for WPI inflation are purely naïve type of expectations, only influenced by respondents earlier period expectations. In the case of CPIIW inflation, the results however suggest that the short-term expectations are not purely naïve type, but also contain adaptive as well as a static forms of expectations. This means that respondents consider their previous forecast errors about CPIIW inflation and draw recent price developments in the CPIIW while forming their overall short-term inflation expectations. This finding provides some formal evidence that the CPI based inflation measure is better suited, than WPI inflation, as a nominal anchor in the RBI’s recent transition to inflation targeting regime. JEL classification: D84, E31, E52, E37, Keywords: Inflation, Inflation expectations, Survey data, Price index, Monetary policy, Forecasting
Inflation of a Polymeric Menbrane
DEFF Research Database (Denmark)
Kristensen, Susanne B.; Larsen, Johannes R.; Hassager, Ole
1998-01-01
We consider an axisymmetric polymeric membrane inflated by a uniform pressure difference acting across the membrane.......We consider an axisymmetric polymeric membrane inflated by a uniform pressure difference acting across the membrane....
Accidental inflation from Kähler uplifting
Energy Technology Data Exchange (ETDEWEB)
Ben-Dayan, Ido; Westphal, Alexander; Wieck, Clemens [Deutsches Elektronen-Synchrotron DESY, Theory Group, Notkestrasse 85, D-22603 Hamburg (Germany); Jing, Shenglin, E-mail: ido.bendayan@desy.de, E-mail: shenglin.jing@utoronto.ca, E-mail: alexander.westphal@desy.de, E-mail: clemens.wieck@desy.de [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St.George Street, Toronto, ON, M5S 3H8 (Canada)
2014-03-01
We analyze the possibility of realizing inflation with a subsequent dS vacuum in the Käahler uplifting scenario. The inclusion of several quantum corrections to the 4d effective action evades previous no-go theorems and allows for construction of simple and successful models of string inflation. The predictions of several benchmark models are in accord with current observations, i.e., a red spectral index, negligible non-gaussianity, and spectral distortions similar to the simplest models of inflation. A particularly interesting subclass of models are ''left-rolling'' ones, where the overall volume of the compactified dimensions shrinks during inflation. We call this phenomenon ''inflation by deflation'' (IBD), where deflation refers to the internal manifold. This subclass has the appealing features of being insensitive to initial conditions, avoiding the overshooting problem, and allowing for observable running α ∼ 0.012 and enhanced tensor-to-scalar ratio r ∼ 10{sup −5}. The latter results differ significantly from many string inflation models.
When Parents' Praise Inflates, Children's Self-Esteem Deflates.
Brummelman, Eddie; Nelemans, Stefanie A; Thomaes, Sander; Orobio de Castro, Bram
2017-11-01
Western parents often give children overly positive, inflated praise. One perspective holds that inflated praise sets unattainable standards for children, eventually lowering children's self-esteem (self-deflation hypothesis). Another perspective holds that children internalize inflated praise to form narcissistic self-views (self-inflation hypothesis). These perspectives were tested in an observational-longitudinal study (120 parent-child dyads from the Netherlands) in late childhood (ages 7-11), when narcissism and self-esteem first emerge. Supporting the self-deflation hypothesis, parents' inflated praise predicted lower self-esteem in children. Partly supporting the self-inflation hypothesis, parents' inflated praise predicted higher narcissism-but only in children with high self-esteem. Noninflated praise predicted neither self-esteem nor narcissism. Thus, inflated praise may foster the self-views it seeks to prevent. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.
Constant-roll tachyon inflation and observational constraints
Gao, Qing; Gong, Yungui; Fei, Qin
2018-05-01
For the constant-roll tachyon inflation, we derive the analytical expressions for the scalar and tensor power spectra, the scalar and tensor spectral tilts and the tensor to scalar ratio to the first order of epsilon1 by using the method of Bessel function approximation. The derived ns-r results are compared with the observations, we find that only the constant-roll inflation with ηH being a constant is consistent with the observations and observations constrain the constant-roll inflation to be slow-roll inflation. The tachyon potential is also reconstructed for the constant-roll inflation which is consistent with the observations.
Energy Technology Data Exchange (ETDEWEB)
Ellis, John [Theoretical Particle Physics and Cosmology Group, Department of Physics, King’s College London, Strand, London WC2R 2LS (United Kingdom); Theory Division, CERN, Route de Meyrin 385, 1217 Meyrin (Switzerland); Gonzalo, Tomás E.; Harz, Julia; Huang, Wei-Chih [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
2015-03-23
We analyse the prospects for constructing hybrid models of inflation that provide a dynamical realisation of the apparent closeness between the supersymmetric GUT scale and the possible scale of cosmological inflation. In the first place, we consider models based on the flipped SU(5)×U(1) gauge group, which has no magnetic monopoles. In one model, the inflaton is identified with a sneutrino field, and in the other model it is a gauge singlet. In both cases we find regions of the model parameter spaces that are compatible with the experimental magnitudes of the scalar perturbations, A{sub s}, and the tilt in the scalar perturbation spectrum, n{sub s}, as well as with an indicative upper limit on the tensor-to-scalar perturbation ratio, r. We also discuss embeddings of these models into SO(10), which is broken at a higher scale so that its monopoles are inflated away.
Energy Technology Data Exchange (ETDEWEB)
Ellis, John [Theoretical Particle Physics and Cosmology Group, Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Gonzalo, Tomás E.; Harz, Julia; Huang, Wei-Chih, E-mail: john.ellis@cern.ch, E-mail: tomas.gonzalo.11@ucl.ac.uk, E-mail: j.harz@ucl.ac.uk, E-mail: wei-chih.huang@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
2015-03-01
We analyse the prospects for constructing hybrid models of inflation that provide a dynamical realisation of the apparent closeness between the supersymmetric GUT scale and the possible scale of cosmological inflation. In the first place, we consider models based on the flipped SU(5)×U(1) gauge group, which has no magnetic monopoles. In one model, the inflaton is identified with a sneutrino field, and in the other model it is a gauge singlet. In both cases we find regions of the model parameter spaces that are compatible with the experimental magnitudes of the scalar perturbations, A{sub s}, and the tilt in the scalar perturbation spectrum, n{sub s}, as well as with an indicative upper limit on the tensor-to-scalar perturbation ratio, r. We also discuss embeddings of these models into SO(10), which is broken at a higher scale so that its monopoles are inflated away.
Ellis, John; Harz, Julia; Huang, Wei-Chih
2015-01-01
We analyse the prospects for constructing hybrid models of inflation that provide a dynamical realisation of the apparent closeness between the supersymmetric GUT scale and the possible scale of cosmological inflation. In the first place, we consider models based on the flipped SU(5)$\\times$U(1) gauge group, which has no magnetic monopoles. In one model, the inflaton is identified with a sneutrino field, and in the other model it is a gauge singlet. In both cases we find regions of the model parameter spaces that are compatible with the experimental magnitudes of the scalar perturbations, $A_s$, and the tilt in the scalar perturbation spectrum, $n_s$, as well as with an indicative upper limit on the tensor-to-scalar perturbation ratio, $r$. We also discuss embeddings of these models into SO(10), which is broken at a higher scale so that its monopoles are inflated away.
On inflation in the heterotic superstring model
International Nuclear Information System (INIS)
Maeda, K.; Pollock, M.D.
1985-11-01
We consider the possibility of achieving inflation in the field-theory limit of the E 8 xE 8 superstring model. We show that neither type I inflation nor inflation due to a SUSY-breaking gaugino-condensation potential, is possible, essentially because of the absence of free dimensionless parameters. Kaluza-Klein type inflation is ruled out because the internal space is Ricci flat. The occurrence of type II inflation (due to some gauge singlet 'inflaton' field phi) depends upon the form of the superpotential F and of the Kaehler potential G, but this also seems not to be possible, unless the SU(n,1) symmetry can be broken in a particular way. Hence, some new type of compactification scheme may be called for, or a different type of inflation
Energy Technology Data Exchange (ETDEWEB)
Green, Daniel; Horn, Bart; /SLAC /Stanford U., Phys. Dept.; Senatore, Leonardo; /Princeton, Inst. Advanced Study /Harvard U., Phys. Dept. /Harvard-Smithsonian Ctr. Astrophys.; Silverstein, Eva; /SLAC /Stanford U., Phys. Dept.
2009-06-19
We analyze a distinctive mechanism for inflation in which particle production slows down a scalar field on a steep potential, and show how it descends from angular moduli in string compactifications. The analysis of density perturbations - taking into account the integrated effect of the produced particles and their quantum fluctuations - requires somewhat new techniques that we develop. We then determine the conditions for this effect to produce sixty e-foldings of inflation with the correct amplitude of density perturbations at the Gaussian level, and show that these requirements can be straightforwardly satisfied. Finally, we estimate the amplitude of the non-Gaussianity in the power spectrum and find a significant equilateral contribution.
Consumer's inflation expectations in Brazil
Directory of Open Access Journals (Sweden)
Fernando Ormonde Teixeira
Full Text Available Abstract This paper investigates what are the main components of consumer's inflation expectations. We combine the FGV's Consumer Survey with the indices of inflation (IPCA and government regulated prices, professional forecasts disclosed in the Focus report, and media data which we crawl from one of the biggest and most important Brazilian newspapers, Folha de São Paulo, to determine what factors are responsible for and improve consumer's forecast accuracy. We found gender, age and city of residence as major elements when analyzing micro-data. Aggregate data shows the past inflation as an important trigger in the formation of consumers' expectations and professional forecasts as negligible. Moreover, the media plays a significant role, accounting not only for the expectations' formation but for a better understanding of actual inflation as well.
Aspects of supersymmetric inflation
International Nuclear Information System (INIS)
Lindblom, P.R.
1987-01-01
A new supersymmetric inflationary model is presented and shown to possess the following features: a successful slow rollover produced by quantum corrections; an acceptable pattern of supersymmetry breaking leading to the correct value of the electroweak scale; and a stable slow rollover transition to a minimum with vanishing cosmological constant. It is demonstrated that there is a class of GUT models which are compatible with an inflationary universe scenario in which: (a) the GUT and inflationary phase transitions are distinct (as in supersymmetric inflation); and (b) an observable number of GUT monopoles are created thermally due to reheating of the GUT sector after inflation. This provides one of the few ways of reconciling an observation of GUT monopoles with inflation. New techniques are developed for constructing inflationary models with multiple inflation fields, such as generalizing the one-dimensional slow rollover constraints and estimating the contribution to δρ/ρ from fluctuations transverse to the path of the slow rollover. A new method for ending the slow rollover portion of the inflationary transition is developed
Effect of the length of inflation on angular TT and TE power spectra in power-law inflation
International Nuclear Information System (INIS)
Hirai, Shiro; Takami, Tomoyuki
2006-01-01
The effect of the length of inflation on the power spectra of scalar and tensor perturbations is estimated using the power-law inflation model with a scale factor of a(η) = (-η) p = t q . Considering various pre-inflation models with radiation-dominated or scalar matter-dominated periods before inflation in combination with two matching conditions, the temperature angular power spectrum (TT) and temperature-polarization cross-power spectrum (TE) are calculated and a likelihood analysis is performed. It is shown that the discrepancies between the Wilkinson microwave anisotropy probe (WMAP) data and the ΛCDM model, such as suppression of the spectrum at l = 2, 3 and oscillatory behaviour, may be explained by the finite length of inflation model if the length of inflation is near 60 e-folds and q ≥ 300. The proposed models retain similar values of χ 2 to that achieved by the ΛCDM model with respect to fit to the WMAP data, but display different characteristics of the angular TE power spectra at l ≤ 20
Anisotropic constant-roll inflation
Energy Technology Data Exchange (ETDEWEB)
Ito, Asuka; Soda, Jiro [Kobe University, Department of Physics, Kobe (Japan)
2018-01-15
We study constant-roll inflation in the presence of a gauge field coupled to an inflaton. By imposing the constant anisotropy condition, we find new exact anisotropic constant-roll inflationary solutions which include anisotropic power-law inflation as a special case. We also numerically show that the new anisotropic solutions are attractors in the phase space. (orig.)
The inflation sector of extended inflation
International Nuclear Information System (INIS)
Kolb, E.W.
1990-11-01
In extended inflation the inflationary era is brought to a close by the process of percolation of true vacuum bubbles produced in a first-order phase transition. In this paper I discuss several effects that might obtain if the Universe undergoes an inflationary first-order phase transition. 17 refs
Robustness of inflation to inhomogeneous initial conditions
Energy Technology Data Exchange (ETDEWEB)
Clough, Katy; Lim, Eugene A. [Theoretical Particle Physics and Cosmology Group, Physics Department, Kings College London, Strand, London WC2R 2LS (United Kingdom); DiNunno, Brandon S.; Fischler, Willy; Flauger, Raphael; Paban, Sonia, E-mail: katy.clough@kcl.ac.uk, E-mail: eugene.a.lim@gmail.com, E-mail: bsd86@physics.utexas.edu, E-mail: fischler@physics.utexas.edu, E-mail: flauger@physics.utexas.edu, E-mail: paban@physics.utexas.edu [Department of Physics, The University of Texas at Austin, Austin, TX, 78712 (United States)
2017-09-01
We consider the effects of inhomogeneous initial conditions in both the scalar field profile and the extrinsic curvature on different inflationary models. In particular, we compare the robustness of small field inflation to that of large field inflation, using numerical simulations with Einstein gravity in 3+1 dimensions. We find that small field inflation can fail in the presence of subdominant gradient energies, suggesting that it is much less robust to inhomogeneities than large field inflation, which withstands dominant gradient energies. However, we also show that small field inflation can be successful even if some regions of spacetime start out in the region of the potential that does not support inflation. In the large field case, we confirm previous results that inflation is robust if the inflaton occupies the inflationary part of the potential. Furthermore, we show that increasing initial scalar gradients will not form sufficiently massive inflation-ending black holes if the initial hypersurface is approximately flat. Finally, we consider the large field case with a varying extrinsic curvature K , such that some regions are initially collapsing. We find that this may again lead to local black holes, but overall the spacetime remains inflationary if the spacetime is open, which confirms previous theoretical studies.
An evaluation of inflation expectations in Turkey
Directory of Open Access Journals (Sweden)
Barış Soybilgen
2017-03-01
Full Text Available Expectations of inflation play a critical role in the process of price setting in the market. Central banks closely follow developments in inflation expectations to implement a successful monetary policy. The Central Bank of the Republic of Turkey (CBRT conducts a survey of experts and decision makers in the financial and real sectors to reveal market expectations and predictions of current and future inflation. The survey is conducted every month. This paper examines the accuracy of these survey predictions using forecast evaluation techniques. We focus on both point and sign accuracy of the predictions. Although point predictions from CBRT surveys are compared with those of autoregressive models, sign predictions are evaluated on their value to a user. We also test the predictions for bias. Unlike the empirical evidence from other economies, our results show that autoregressive models outperform most of inflation expectations in forecasting inflation. This indicates that inflation expectations have poor point forecast accuracies. However, we show that sign predictions for all inflation expectations have value to a user.
Inflation targeting and economic performance: The case of Mexico
Directory of Open Access Journals (Sweden)
Carrasco Carlos A.
2011-01-01
Full Text Available In the paper we analyze the impact of Inflation Targeting (IT in Mexico. The objective is to evaluate the impact of the implementation of inflation targeting and full-fledged inflation targeting (FFIT on the level and the variability of the inflation and the output in the Mexican economy. We conclude that inflation rates had been reduced in Mexico before the introduction of IT and FFIT. In our opinion, the structural reforms, including the Banxico reforms, are the main determinants of the decrease in inflation and its variability. The main impact of IT would have been the lock-in of inflation expectations around a low rate of inflation.
Determinant and impacts of dynamic inflation in Ethiopia
Biresaw, Temesgen Tezera
2014-01-01
This thesis uses quarterly data for the period 1998-2010 to investigate the determinant and impacts of dynamic inflation in Ethiopia. By using Granger causality model approach four testable hypotheses are investigated: (1) does the money supply growth Granger-cause inflation? (2) Does currency devaluation Granger cause inflation? (3) Does inflation affect economic growth? And (4) Does oil price Granger cause of inflation? The empirical results suggest that there existed a bi-directional ...
Project Evaluation under Inflation Condition
International Nuclear Information System (INIS)
Hindy, M.; El Missiry, P.
2004-01-01
This paper analyzes the role of inflation in capital budgeting and attempts to introduce solutions to such implication in order to make the appropriate decision for the firm' stockholders under these circumstances. Inflation leads to biasness in evaluating the investment projects, due to its impact on the cash flow, the discount rate, the initial investment cost, and the depreciation. This paper has shown that the capital budgeting process is not neutral with respect to inflation, as the output prices will raise as well as the operating and capital expenditures will also be adjusted due to inflation. In addition, it has shown that it is reasonable to expect that the cost of capital will increase as a result of an increase in the real interest rate, the inflation premium, and the cost of equity. Of critical importance is the basis used in calculating the annual depreciation which may lead to the transfer of wealth from the investment projects to the government and will result in underestimating the net present value of the investment projects, if these depreciation charges is calculated based upon the historical values and not on the replacement cost of the fixed assets
Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D
2016-01-22
We describe a general scenario, dubbed "inflatable dark matter," in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early Universe. The overproduction of dark matter that is predicted within many, otherwise, well-motivated models of new physics can be elegantly remedied within this context. Thermal relics that would, otherwise, be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the nonthermal abundance of grand unified theory or Planck scale axions can be brought to acceptable levels without invoking anthropic tuning of initial conditions. A period of late-time inflation could have occurred over a wide range of scales from ∼MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the standard model.
International Nuclear Information System (INIS)
Chialva, Diego; Danielsson, Ulf H
2008-01-01
This paper represents an in-depth treatment of the chain inflation scenario. We fully determine the evolution of the universe in the model, the conditions necessary in order to have a successful inflationary period, and the matching with the observational results regarding the cosmological perturbations. We study in great detail, and in general, the dynamics of the background, as well as the mechanism of generation of the perturbations. We also find an explicit formula for the spectrum of adiabatic perturbations. Our results prove that chain inflation is a viable model for solving the horizon, entropy and flatness problems of standard cosmology and for generating the right amount of adiabatic cosmological perturbations. The results are radically different from those found in previous works on the subject. Finally, we argue that there is a natural way to embed chain inflation into flux compactified string theory. We discuss the details of the implementation and how to fit observations
On the constant-roll inflation
Yi, Zhu; Gong, Yungui
2018-03-01
The primordial power spectra of scalar and tensor perturbations during slow-roll inflation are usually calculated with the method of Bessel function approximation. For constant-roll or ultra slow-roll inflation, the method of Bessel function approximation may be invalid. We compare the numerical results with the analytical results derived from the Bessel function approximation, and we find that they differ significantly on super-horizon scales if the constant slow-roll parameter ηH is not small. More accurate method is needed for calculating the primordial power spectrum for constant-roll inflation.
D-term uplifted racetrack inflation
Energy Technology Data Exchange (ETDEWEB)
Brax, P. [Unite de Recherche associee au CNRS, Gif sur Yvette (France). Service de Physique Theorique, CEA/DSM/SPhT; Davis, A.C. [Cambridge Univ. (United Kingdom). DAMTP, Centre for Mathematical Sciences; Davis, S.C. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies; Jeannerot, R. [Instituut-Lorentz for Theoretical Physics, Leiden (Netherlands); Postma, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[Nationaal Inst. voor Kernfysica en Hoge-Energiefysica (NIKHEF), Amsterdam (Netherlands)
2007-10-15
It is shown that racetrack inflation can be implemented in a moduli stabilisation scenario with a supersymmetric uplifting D-term. The resulting model is completely described by an effective supergravity theory, in contrast to the original racetrack models. We study the inflationary dynamics and show that the gaugino condensates vary during inflation. The resulting spectral index is n{sub s} {approx}0.95 as in the original racetrack inflation model. Hence extra fields do not appear to alter the predictions of the model. An equivalent, simplified model with just a single field is presented. (orig.)
Accidental Kähler moduli inflation
International Nuclear Information System (INIS)
Maharana, Anshuman; Rummel, Markus; Sumitomo, Yoske
2015-01-01
We study a model of accidental inflation in type IIB string theory where inflation occurs near the inflection point of a small Kähler modulus. A racetrack structure helps to alleviate the known concern that string-loop corrections may spoil Kähler Moduli Inflation unless having a significant suppression via the string coupling or a special brane setup. Also, the hierarchy of gauge group ranks required for the separation between moduli stabilization and inflationary dynamics is relaxed. The relaxation becomes more significant when we use the recently proposed D-term generated racetrack model
78 FR 5722 - Civil Monetary Penalty Inflation Adjustment
2013-01-28
... Civil Monetary Penalty Inflation Adjustment AGENCY: U.S. Army Corps of Engineers, DoD. ACTION: Direct... for inflation. The adjustment of civil penalties to account for inflation is required by the Federal Civil Penalties Inflation Adjustment Act of 1990, as amended. Since we have not made any adjustments to...
78 FR 5760 - Civil Monetary Penalty Inflation Adjustment
2013-01-28
... Civil Monetary Penalty Inflation Adjustment AGENCY: U.S. Army Corps of Engineers, DoD. ACTION: Proposed... account for inflation. The adjustment of civil penalties to account for inflation is required by the Federal Civil Penalties Inflation Adjustment Act of 1990, as amended. Since we have not made any...
Sneutrino hybrid inflation and nonthermal leptogenesis
International Nuclear Information System (INIS)
Antusch, Stefan; Baumann, Jochen P.; Domcke, Valerie F.; Kostka, Philipp M.
2010-01-01
In sneutrino hybrid inflation the superpartner of one of the right-handed neutrinos involved in the seesaw mechanism plays the role of the inflaton field. It obtains its large mass after the ''waterfall'' phase transition which ends hybrid inflation. After this phase transition the oscillations of the sneutrino inflaton field may dominate the universe and efficiently produce the baryon asymmetry of the universe via nonthermal leptogenesis. We investigate the conditions under which inflation, with primordial perturbations in accordance with the latest WMAP results, as well as successful nonthermal leptogenesis can be realized simultaneously within the sneutrino hybrid inflation scenario. We point out which requirements successful inflation and leptogenesis impose on the seesaw parameters, i.e. on the Yukawa couplings and the mass of the right-handed (s)neutrino, and derive the predictions for the CMB observables in terms of the right-handed (s)neutrino mass and the other relevant model parameters
Primordial perturbations in multi-scalar inflation
Energy Technology Data Exchange (ETDEWEB)
Abedi, Habib; Abbassi, Amir M., E-mail: h.abedi@ut.ac.ir, E-mail: amabasi@khayam.ut.ac.ir [Department of Physics, University of Tehran, North Kargar Ave, Tehran (Iran, Islamic Republic of)
2017-07-01
Multiple field models of inflation exhibit new features than single field models. In this work, we study the hierarchy of parameters based on Hubble expansion rate in curved field space and derive the system of flow equations that describe their evolutions. Then we focus on obtaining derivatives of number of e-folds with respect to scalar fields during inflation and at hypersurface of the end of inflation.
Inflation differentials among Czech households
Czech Academy of Sciences Publication Activity Database
Janský, Petr; Hait, Pavel
2016-01-01
Roč. 25, č. 1 (2016), s. 71-84 ISSN 1210-0455 R&D Projects: GA TA ČR(CZ) TD020188 Institutional support: RVO:67985998 Keywords : households * inflation * inflation differentials Subject RIV: AH - Economics Impact factor: 0.710, year: 2016
12 CFR 263.65 - Civil penalty inflation adjustments.
2010-01-01
... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Civil penalty inflation adjustments. 263.65... Money Penalties § 263.65 Civil penalty inflation adjustments. (a) Inflation adjustments. In accordance with the Federal Civil Penalties Inflation Adjustment Act of 1990 (28 U.S.C. 2461 note), the Board has...
Inflation Experiences in Latin America, 2007-2008
Mark Weisbrot; David Rosnick
2009-01-01
This paper looks briefly at the recent inflation experiences of ten Latin American countries: Brazil, Mexico, Venezuela, Colombia, Chile, Peru, Ecuador, Guatemala, the Dominican Republic, and Bolivia. The authors construct a core inflation index (excluding food and energy), and look at three-month changes in both headline and core inflation. The paper focuses on the increase in inflation from April 2007 to July 2008, driven by a surge in food and energy prices worldwide. These prices have sin...
Transdimensional physics and inflation
International Nuclear Information System (INIS)
Giudice, Gian F.; Kolb, Edward W.; Lesgourgues, Julien; Riotto, Antonio
2002-01-01
Within the framework of a five-dimensional brane world with a stabilized radion, we compute the cosmological perturbations generated during inflation and show that the perturbations are a powerful tool to probe the physics of extra dimensions. While we find that the power spectrum of scalar perturbations is unchanged, we show that the existence of the fifth dimension is imprinted on the spectrum of gravitational waves generated during inflation. In particular, we find that the tensor perturbations receive a correction proportional to (HR) 2 , where H is the Hubble expansion rate during inflation and R is the size of the extra dimension. We also generalize our findings to the case of several extra dimensions as well as to warped geometries
Transdimensional physics and inflation
Giudice, Gian Francesco; Lesgourgues, Julien; Riotto, Antonio; Giudice, Gian F.; Kolb, Edward W.; Lesgourgues, Julien; Riotto, Antonio
2002-01-01
Within the framework of a five-dimensional brane world with a stabilized radion, we compute the cosmological perturbations generated during inflation and show that the perturbations are a powerful tool to probe the physics of extra dimensions. While we find that the power spectrum of scalar perturbations is unchanged, we show that the existence of the fifth dimension is imprinted on the spectrum of gravitational waves generated during inflation. In particular, we find that the tensor perturbations receive a correction proportional to (HR)^2, where H is the Hubble expansion rate during inflation and R is the size of the extra dimension. We also generalize our findings to the case of several extra dimensions as well as to warped geometries.
Inflation of Unreefed and Reefed Extraction Parachutes
Ray, Eric S.; Varela, Jose G.
2015-01-01
Data from the Orion and several other test programs have been used to reconstruct inflation parameters for 28 ft Do extraction parachutes as well as the parent aircraft pitch response during extraction. The inflation force generated by extraction parachutes is recorded directly during tow tests but is usually inferred from the payload accelerometer during Low Velocity Airdrop Delivery (LVAD) flight test extractions. Inflation parameters are dependent on the type of parent aircraft, number of canopies, and standard vs. high altitude extraction conditions. For standard altitudes, single canopy inflations are modeled as infinite mass, but the non-symmetric inflations in a cluster are modeled as finite mass. High altitude extractions have necessitated reefing the extraction parachutes, which are best modeled as infinite mass for those conditions. Distributions of aircraft pitch profiles and inflation parameters have been generated for use in Monte Carlo simulations of payload extractions.
Kehagias, Alex
2017-01-01
We investigate the recently proposed clockwork mechanism delivering light degrees of freedom with suppressed interactions and show, with various examples, that it can be efficiently implemented in inflationary scenarios to generate flat inflaton potentials and small density perturbations without fine-tunings. We also study the clockwork graviton in de Sitter and, interestingly, we find that the corresponding clockwork charge is site-dependent. As a consequence, the amount of tensor modes is generically suppressed with respect to the standard cases where the clockwork set-up is not adopted. This point can be made a virtue in resurrecting models of inflation which were supposed to be ruled out because of the excessive amount of tensor modes from inflation.
Ellis, John; Gonzalo, Tomás E.; Harz, Julia; Huang, Wei-Chih
2015-01-01
We analyse the prospects for constructing hybrid models of inflation that provide a dynamical realisation of the apparent closeness between the supersymmetric GUT scale and the possible scale of cosmological inflation. In the first place, we consider models based on the flipped SU(5)×U(1) gauge group, which has no magnetic monopoles. In one model, the inflaton is identified with a sneutrino field, and in the other model it is a gauge singlet. In both cases we find regions of the model paramet...
International Nuclear Information System (INIS)
Chimento, Luis P.
2002-01-01
We find the group of symmetry transformations under which the Einstein equations for the spatially flat Friedmann-Robertson-Walker universe are form invariant. They relate the energy density and the pressure of the fluid to the expansion rate. We show that inflation can be obtained from nonaccelerated scenarios by a symmetry transformation. We derive the transformation rule for the spectrum and spectral index of the curvature perturbations. Finally, the group is extended to investigate inflation in the anisotropic Bianchi type-I spacetime and the brane-world cosmology
Inflatable Re-Entry Vehicle Experiment (IRVE) Design Overview
Hughes, Stephen J.; Dillman, Robert A.; Starr, Brett R.; Stephan, Ryan A.; Lindell, Michael C.; Player, Charles J.; Cheatwood, F. McNeil
2005-01-01
Inflatable aeroshells offer several advantages over traditional rigid aeroshells for atmospheric entry. Inflatables offer increased payload volume fraction of the launch vehicle shroud and the possibility to deliver more payload mass to the surface for equivalent trajectory constraints. An inflatable s diameter is not constrained by the launch vehicle shroud. The resultant larger drag area can provide deceleration equivalent to a rigid system at higher atmospheric altitudes, thus offering access to higher landing sites. When stowed for launch and cruise, inflatable aeroshells allow access to the payload after the vehicle is integrated for launch and offer direct access to vehicle structure for structural attachment with the launch vehicle. They also offer an opportunity to eliminate system duplication between the cruise stage and entry vehicle. There are however several potential technical challenges for inflatable aeroshells. First and foremost is the fact that they are flexible structures. That flexibility could lead to unpredictable drag performance or an aerostructural dynamic instability. In addition, durability of large inflatable structures may limit their application. They are susceptible to puncture, a potentially catastrophic insult, from many possible sources. Finally, aerothermal heating during planetary entry poses a significant challenge to a thin membrane. NASA Langley Research Center and NASA's Wallops Flight Facility are jointly developing inflatable aeroshell technology for use on future NASA missions. The technology will be demonstrated in the Inflatable Re-entry Vehicle Experiment (IRVE). This paper will detail the development of the initial IRVE inflatable system to be launched on a Terrier/Orion sounding rocket in the fourth quarter of CY2005. The experiment will demonstrate achievable packaging efficiency of the inflatable aeroshell for launch, inflation, leak performance of the inflatable system throughout the flight regime, structural
Multi-brid inflation and non-gaussianity
International Nuclear Information System (INIS)
Sasaki, Misao
2008-01-01
We consider a class of multi-component hybrid inflation models whose evolution may be analytically solved under the slow-roll approximation. We call it multi-brid inflation (or n-brid inflation where n stands for the number of inflaton fields). As an explicit example, we consider a two-brid inflation model, in which the inflaton potentials are of exponential type and a waterfall field that terminates inflation has the standard quartic potential with two minima. Using the δN formalism, we derive an expression for the curvature perturbation valid to full nonlinear order. Then we give an explicit expression for the curvature perturbation to second order in the inflaton perturbation. We find that the final from of the curvature perturbation depends crucially on how the inflation ends. Using this expression, we present closed analytical expressions for the spectrum of the curvature perturbation Ps(k), the spectral index n s , the tensor to scalar ratio r, and the non-Gaussian parameter f NL local , in terms of the model parameters. We find that a wide range of the parameter space (n s , r, f NL local ) can be covered by varying the model parameters within a physically reasonable range. In particular, for plausible values of the model parameters, we may have a large non-Gaussianity f NL local ∼10-100. This is in sharp contrast to the case of single-field hybrid inflation in which these parameters are tightly constrained. (author)
Does string theory lead to extended inflation?
Campbell, Bruce A.; Linde, Andrei; Olive, Keith A.
1991-05-01
We consider the relationship between string theory and currently proposed models of extended inflation. In doing so, we discuss the conformal actions in string theory and in Jordan-Brans-Dicke gravity. We show explicitly the equivalence of pictures in which either gauge or gravitational couplings are changing with time. We demonstrate that the existence of the dilation in string theory does not naturally lead to extended inflation as currently discussed. We also discuss the resolution of the graceful exit problem of old inflation in Einstein gravity using either power-law inflation, or exponential inflation with a changing bubble formation rate. On leave of absence from School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, USA.
String cosmology. Large-field inflation in string theory
International Nuclear Information System (INIS)
Westphal, Alexander
2014-09-01
This is a short review of string cosmology. We wish to connect string-scale physics as closely as possible to observables accessible to current or near-future experiments. Our possible best hope to do so is a description of inflation in string theory. The energy scale of inflation can be as high as that of Grand Unification (GUT). If this is the case, this is the closest we can possibly get in energy scales to string-scale physics. Hence, GUT-scale inflation may be our best candidate phenomenon to preserve traces of string-scale dynamics. Our chance to look for such traces is the primordial gravitational wave, or tensor mode signal produced during inflation. For GUT-scale inflation this is strong enough to be potentially visible as a B-mode polarization of the cosmic microwave background (CMB). Moreover, a GUT-scale inflation model has a trans-Planckian excursion of the inflaton scalar field during the observable amount of inflation. Such large-field models of inflation have a clear need for symmetry protection against quantum corrections. This makes them ideal candidates for a description in a candidate fundamental theory like string theory. At the same time the need of large-field inflation models for UV completion makes them particularly susceptible to preserve imprints of their string-scale dynamics in the inflationary observables, the spectral index n s and the fractional tensor mode power r. Hence, we focus this review on axion monodromy inflation as a mechanism of large-field inflation in string theory.
Regional Inflation and Financial Dollarization
Brown, M.; de Haas, R.; Sokolov, V.
2013-01-01
Abstract: We exploit variation in consumer price inflation across 71 Russian regions to examine the relationship between the perceived stability of the local currency and financial dollarization. Our results show that regions with higher inflation experience an increase in the dollarization of
Symmetry breaking patterns for inflation
Klein, Remko; Roest, Diederik; Stefanyszyn, David
2018-06-01
We study inflationary models where the kinetic sector of the theory has a non-linearly realised symmetry which is broken by the inflationary potential. We distinguish between kinetic symmetries which non-linearly realise an internal or space-time group, and which yield a flat or curved scalar manifold. This classification leads to well-known inflationary models such as monomial inflation and α-attractors, as well as a new model based on fixed couplings between a dilaton and many axions which non-linearly realises higher-dimensional conformal symmetries. In this model, inflation can be realised along the dilatonic direction, leading to a tensor-to-scalar ratio r ˜ 0 .01 and a spectral index n s ˜ 0 .975. We refer to the new model as ambient inflation since inflation proceeds along an isometry of an anti-de Sitter ambient space-time, which fully determines the kinetic sector.
Taxation, Fiscal Deficit and Inflation in Pakistan
Directory of Open Access Journals (Sweden)
Ghulam Rasool Madni
2014-09-01
Full Text Available Fiscal policy has more controversial debate regarding its effectiveness on different macroeconomic activities of an economy. Taxation and government expenditure are two main instruments of fiscal policy. This paper is aimed to analyze and update the effects of different instruments of fiscal policy on inflation in Pakistan economy. The data time span for this study is 1979-2013. The impact of fiscal policy on inflation is analyzed by utilizing the Bounds testing procedure and ARDL approach of co-integration which is a better estimation technique for small sample size. It is found that investment negatively and significantly affect the inflation rate. The outcomes of the study show that both types of taxes (direct and indirect are causing to increase the inflation level while fiscal deficit is also one of the reasons to increase the inflation in the country. The study proposed that government should decrease the level of expenditure to reduce the level of fiscal deficit and investment have to be promoted to decrease the inflation in the country. Furthermore, it is also suggested to decrease the level of taxation for controlling inflation.
Sneutrino hybrid inflation and nonthermal leptogenesis
Energy Technology Data Exchange (ETDEWEB)
Antusch, Stefan; Baumann, Jochen P.; Domcke, Valerie F.; Kostka, Philipp M., E-mail: antusch@mppmu.mpg.de, E-mail: jbaumann@mppmu.mpg.de, E-mail: domcke@mppmu.mpg.de, E-mail: kostka@mppmu.mpg.de [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany)
2010-10-01
In sneutrino hybrid inflation the superpartner of one of the right-handed neutrinos involved in the seesaw mechanism plays the role of the inflaton field. It obtains its large mass after the ''waterfall'' phase transition which ends hybrid inflation. After this phase transition the oscillations of the sneutrino inflaton field may dominate the universe and efficiently produce the baryon asymmetry of the universe via nonthermal leptogenesis. We investigate the conditions under which inflation, with primordial perturbations in accordance with the latest WMAP results, as well as successful nonthermal leptogenesis can be realized simultaneously within the sneutrino hybrid inflation scenario. We point out which requirements successful inflation and leptogenesis impose on the seesaw parameters, i.e. on the Yukawa couplings and the mass of the right-handed (s)neutrino, and derive the predictions for the CMB observables in terms of the right-handed (s)neutrino mass and the other relevant model parameters.
Higgs portal valleys, stability and inflation
Ballesteros, Guillermo
2015-01-01
The measured values of the Higgs and top quark masses imply that the Standard Model potential is very likely to be unstable at large Higgs values. This is particularly problematic during inflation, which sources large perturbations of the Higgs. The instability could be cured by a threshold effect induced by a scalar with a large vacuum expectation value and directly connected to the Standard Model through a Higgs portal coupling. However, we find that in a minimal model in which the scalar generates inflation, this mechanism does not stabilize the potential because the mass required for inflation is beyond the instability scale. This conclusion does not change if the Higgs has a direct weak coupling to the scalar curvature. On the other hand, if the potential is absolutely stable, successful inflation in agreement with current CMB data can occur along a valley of the potential with a Mexican hat profile. We revisit the stability conditions, independently of inflation, and clarify that the threshold effect ca...
Supersymmetric moduli stabilization and high-scale inflation
International Nuclear Information System (INIS)
Buchmueller, Wilfried; Wieck, Clemens; Winkler, Martin Wolfgang
2014-04-01
We study the back-reaction of moduli fields on the inflaton potential in generic models of F-term inflation. We derive the moduli corrections as a power series in the ratio of Hubble scale and modulus mass. The general result is illustrated with two examples, hybrid inflation and chaotic inflation. We find that in both cases the decoupling of moduli dynamics and inflation requires moduli masses close to the scale of grand unification. For smaller moduli masses the CMB observables are strongly affected.
Primordial inflation and the monopole problem
International Nuclear Information System (INIS)
Olive, K.A.; Seckel, D.
1984-01-01
This chapter discusses the cosmological abundance of magnetic monopoles in locally supersymmetry grand unified theories (GUTs) and primordial inflation. It is shown how the magnetic monopole problem can be solved in variants of broken N=1 supergravity primordial inflation. The monopole problem and its solution in inflationary models is reviewed. It is demonstrated that the monopole problem can be solved by coupling primordial inflation to supersymmetric SU(5) breaking
DEFF Research Database (Denmark)
Channuie, Phongpichit; Jark Joergensen, Jakob; Sannino, Francesco
2011-01-01
We investigate models in which the inflaton emerges as a composite field of a four dimensional, strongly interacting and nonsupersymmetric gauge theory featuring purely fermionic matter. We show that it is possible to obtain successful inflation via non-minimal coupling to gravity, and that the u......We investigate models in which the inflaton emerges as a composite field of a four dimensional, strongly interacting and nonsupersymmetric gauge theory featuring purely fermionic matter. We show that it is possible to obtain successful inflation via non-minimal coupling to gravity...
Forecasting Interest Rates and Inflation
DEFF Research Database (Denmark)
Chun, Albert Lee
the best overall for short horizon forecasts of short to medium term yields and inflation. Econometric models with shrinkage perform the best over longer horizons and maturities. Aggregating over a larger set of analysts improves inflation surveys while generally degrading interest rates surveys. We...
Bianchi models and new inflation
International Nuclear Information System (INIS)
Turner, M.S.; Widrow, L.
1986-03-01
The promise of the inflationary Universe scenario is to free the present state of the Universe from extreme dependence on initial data. Paradoxically, inflation is usually analyzed in the context of the homogeneous and isotropic Robertson-Walker (RW) cosmological models. We show that all but a small subset of the homogeneous models (the Bianchi models) undergo inflation. Any initial anisotropy is so strongly damped that if sufficient inflation occurs to solve the flatness/horizon problems the Universe today would still be very isotropic. Some of the Bianchi models will eventually (in the exponentially distant future) become very anisotropic again. 15 refs
Natural inflation and quantum gravity.
de la Fuente, Anton; Saraswat, Prashant; Sundrum, Raman
2015-04-17
Cosmic inflation provides an attractive framework for understanding the early Universe and the cosmic microwave background. It can readily involve energies close to the scale at which quantum gravity effects become important. General considerations of black hole quantum mechanics suggest nontrivial constraints on any effective field theory model of inflation that emerges as a low-energy limit of quantum gravity, in particular, the constraint of the weak gravity conjecture. We show that higher-dimensional gauge and gravitational dynamics can elegantly satisfy these constraints and lead to a viable, theoretically controlled and predictive class of natural inflation models.
Inflation impact of food prices: Case of Serbia
Directory of Open Access Journals (Sweden)
Šoškić Dejan
2015-01-01
Full Text Available Food prices traditionally have an impact on inflation around the world. Movements in these prices are coming more from the supply side, then from the demand side. If treated as a supply shock, monetary policy should not react. However, food prices are part of headline inflation that is an official target for most central banks. Serbia conducts Inflation targeting and faces serious challenges with food price volatility. Food price volatility in Serbia hampers inflation forecasting, and may have a negative influence on inflationary expectations and public confidence in (i.e. credibility of the Central bank, all of crucial importance for success of Inflation targeting. There are several important possible improvements that may decrease volatility of food prices but also limit negative impact of food price volatility on Consumer Price Index (CPI as a measure of inflation. These improvements are very important for success of Inflation targeting in Serbia.
Detection of gravitational waves from inflation
International Nuclear Information System (INIS)
Kamionkowski, M.; Jaffe, A.H.
2001-01-01
Recent measurements of temperature fluctuations in the cosmic microwave background (CMB) indicate that the Universe is flat and that large-scale structure grew via gravitational infall from primordial adiabatic perturbations. Both of these observations seem to indicate that we are on the right track with inflation. But what is the new physics responsible for inflation? This question can be answered with observations of the polarization of the CMB. Inflation predicts robustly the existence of a stochastic background of cosmological gravitational waves with an amplitude proportional to the square of the energy scale of inflation. This gravitational-wave background induces a unique signature in the polarization of the CMB. If inflation took place at an energy scale much smaller than that of grand unification, then the signal will be too small to be detectable. However, if inflation had something to do with grand unification or Planck-scale physics, then the signal is conceivably detectable in the optimistic case by the Planck satellite, or if not, then by a dedicated post-Planck CMB polarization experiment. Realistic developments in detector technology as well as a proper scan strategy could produce such a post-Planck experiment that would improve on Planck's sensitivity to the gravitational-wave background by several orders of magnitude in a decade timescale. (author)
Gratton, Steven
2011-09-01
In this paper we present a path integral formulation of stochastic inflation. Volume weighting can be naturally implemented from this new perspective in a very straightforward way when compared to conventional Langevin approaches. With an in-depth study of inflation in a quartic potential, we investigate how the inflaton evolves and how inflation typically ends both with and without volume weighting. The calculation can be carried to times beyond those accessible to conventional Fokker-Planck approaches. Perhaps unexpectedly, complex histories sometimes emerge with volume weighting. The reward for this excursion into the complex plane is an insight into how volume-weighted inflation both loses memory of initial conditions and ends via slow roll. The slow-roll end of inflation mitigates certain “Youngness Paradox”-type criticisms of the volume-weighted paradigm. Thus it is perhaps time to rehabilitate proper-time volume weighting as a viable measure for answering at least some interesting cosmological questions.
International Nuclear Information System (INIS)
Gratton, Steven
2011-01-01
In this paper we present a path integral formulation of stochastic inflation. Volume weighting can be naturally implemented from this new perspective in a very straightforward way when compared to conventional Langevin approaches. With an in-depth study of inflation in a quartic potential, we investigate how the inflaton evolves and how inflation typically ends both with and without volume weighting. The calculation can be carried to times beyond those accessible to conventional Fokker-Planck approaches. Perhaps unexpectedly, complex histories sometimes emerge with volume weighting. The reward for this excursion into the complex plane is an insight into how volume-weighted inflation both loses memory of initial conditions and ends via slow roll. The slow-roll end of inflation mitigates certain ''Youngness Paradox''-type criticisms of the volume-weighted paradigm. Thus it is perhaps time to rehabilitate proper-time volume weighting as a viable measure for answering at least some interesting cosmological questions.
Perturbative analysis of multiple-field cosmological inflation
International Nuclear Information System (INIS)
Lahiri, Joydev; Bhattacharya, Gautam
2006-01-01
We develop a general formalism for analyzing linear perturbations in multiple-field cosmological inflation based on the gauge-ready approach. Our inflationary model consists of an arbitrary number of scalar fields with non-minimal kinetic terms. We solve the equations for scalar- and tensor-type perturbations during inflation to the first order in slow roll, and then obtain the super-horizon solutions for adiabatic and isocurvature perturbations after inflation. Analytic expressions for power-spectra and spectral indices arising from multiple-field inflation are presented
The Determinants of Inflation in Pakistan: An Econometric Analysis
Directory of Open Access Journals (Sweden)
Nazima Ellahi
2017-09-01
Full Text Available Inflation is not just a rise in general price level, but a much more complex phenomenon. It is well admitted fact that mild inflation is natural and a greasing factor to the wheel of economy and commerce and on the other hand, high inflation causes negative impact on economy. In order to formulate policies regarding its control and keeping it at a moderate level, it is necessary to explore its major determinants. Present study is an attempt to discuss the determinants of inflation in Pakistan utilizing a data set over 1975 to 2015. The empirical analysis is carried out with application of Auto Regressive Distributed Lag methodology. The estimation methods find the short run and long run impact of each variable on inflation and also found the speed of adjustment. Analysis used money supply, national expenditure, imports of goods and services and GDP growth as exogenous variables while taking inflation as an endogenous variable. Major preliminary findings suggested that money supply and national expenditure have significant effect on inflation, where national expenditure has a positive impact on inflation but money supply implies negative impact on inflation. Moreover, GDP growth has negative impact on inflation and imports of goods and services have positive impact on inflation. The findings for short run effect showed that none of the variable proves to be a significant determinant of inflation in short run. In sum, study suggested a few policy recommendations for keeping the inflation at level required for country to grow.
Multifield DBI Inflation and Non-Gaussianities
Huang, Min-xin; Underwood, Bret
2008-01-01
We analyze the trajectories for multifield DBI inflation, which can arise in brane inflation models, and show that the trajectories are the same as in typical slow roll inflation. We calculate the power spectrum and find that the higher derivative terms of the DBI action lead to a suppression of the contribution from the isocurvature perturbations. We also calculate the bispectrum generated by the isocurvature perturbation, and find that it leads to distinctive features.
Inflation and Stock Prices: No Illusion
Chao Wei
2007-01-01
Campbell and Vuolteenaho (2004) use VAR results to advocate inflation illusion as the explanation for the positive association between inflation and the dividend yield. Contrary to their results, we find that a fully rational dynamic general equilibrium model can generate a positive correlation between the dividend yield and inflation of comparable size to its data counterpart. The model results support a proxy hypothesis, according to which, a third factor, which in our model represents tech...
Inflation Dynamics in India: An Analysis
Nair, Manju S
2014-01-01
India has exhibited high variability in inflation during the last eight years owing to both internal and external factors. The Global Financial Meltdown, recurrent increase in global oil prices, wage employment programmes, widening current account deficits etc resulted in fluctuations in inflation. These factors have a direct influence on variables like output, money supply, exchange rate which in turn affect inflation. In this context, the study employs a Cointegrated Vector Auto Regressi...
Towards natural inflation in string theory
International Nuclear Information System (INIS)
Ben-Dayan, Ido; Pedro, Francisco G.; Westphal, Alexander
2014-07-01
We provide type IIB string embeddings of two axion variants of natural inflation. We use a combination of RR 2 form axions as the inflaton field and have its potential generated by non perturbative effects in the superpotential. Besides giving rise to inflation, the models developed take into account the stabilization of the compact space, both in the KKLT and large volume scenario regimes, an essential condition for any semi-realistic model of string inflation.
THE PROSPECT OF INFLATION TARGETING IN KAZAKHSTAN
Directory of Open Access Journals (Sweden)
Zhandos Ybrayev
2017-02-01
Full Text Available Over the last two decades, there has been a significant increase in the number of countries that began to pursue an Inflation Targeting monetary policy framework. Since the collapse of the Soviet Union, each of the fifteen newly created independent countries started to develop and run their own autonomous monetary policies. Kazakhstan announced the implementation of an Inflation Targeting policy in August 2015. At the same time, a number of researches show that Inflation Targeting might not work as well for developing countries as it does for developed ones due to certain fundamental differences and preconditions that must be met before the implementation phase. Thus, this paper discusses the case of Kazakhstan as a typical emerging market economy example, examines its ability to respond to various external shocks and identifies the main transmission channels in order to contribute to the knowledge in this particular area. Identification assumptions generate contemporaneous monetary shocks on domestic inflation behavior, which also take into account various features of the small open economy as well as indicate different important transitory and persistent effects. The results show, based on the interpretation of impulse response functions, a positive interest rate shock has an uncertain inflationary impact, which raises questions about the effectiveness of interest rate manipulation in keeping inflation within the given band. In addition, a positive exchange rate shock leads to a stronger upward pressure in inflation rates. Finally, inflation inertia explains a substantial increase in future inflation rates.
Fibre inflation and α-attractors
Energy Technology Data Exchange (ETDEWEB)
Kallosh, Renata; Linde, Andrei [Stanford Univ., Stanford, CA (United States). Stanford Inst. for Theoretical Physics and Dept. of Physics; Leiden Univ. (Netherlands). Lorentz Inst. for Theoretical Physics; Roest, Diederik [Groningen Univ. (Netherlands). Van Swinderen Inst. for Particle Physics and Gravity; Westphal, Alexander [DESY, Hamburg (Germany). Theory Group; Yamada, Yusuke [Stanford Univ., Stanford, CA (United States). Stanford Inst. for Theoretical Physics and Dept. of Physics
2017-07-15
Fibre inflation is a specific string theory construction based on the Large Volume Scenario that produces an inflationary plateau. We outline its relation to α-attractor models for inflation, with the cosmological sector originating from certain string theory corrections leading to α=2 and α=1/2. Above a certain field range, the steepening effect of higher-order corrections leads first to the breakdown of single-field slow-roll and after that to the onset of 2-field dynamics: the overall volume of the extra dimensions starts to participate in the effective dynamics. Finally, we propose effective supergravity models of fibre inflation based on an D3 uplift term with a nilpotent superfield. Specific moduli dependent D3 induced geometries lead to cosmological fibre models but have in addition a de Sitter minimum exit. These supergravity models motivated by fibre inflation are relatively simple, stabilize the axions and disentangle the Hubble parameter from supersymmetry breaking.
Fibre inflation and α-attractors
Kallosh, Renata; Linde, Andrei; Roest, Diederik; Westphal, Alexander; Yamada, Yusuke
2018-02-01
Fibre inflation is a specific string theory construction based on the Large Volume Scenario that produces an inflationary plateau. We outline its relation to α-attractor models for inflation, with the cosmological sector originating from certain string theory corrections leading to α = 2 and α = 1/2. Above a certain field range, the steepening effect of higher-order corrections leads first to the breakdown of single-field slow-roll and after that to the onset of 2-field dynamics: the overall volume of the extra dimensions starts to participate in the effective dynamics. Finally, we propose effective supergravity models of fibre inflation based on an \\overline{D3} uplift term with a nilpotent superfield. Specific moduli dependent \\overline{D3} induced geometries lead to cosmological fibre models but have in addition a de Sitter minimum exit. These supergravity models motivated by fibre inflation are relatively simple, stabilize the axions and disentangle the Hubble parameter from supersymmetry breaking.
Energy Technology Data Exchange (ETDEWEB)
Dvali, Gia
2003-10-03
We propose a new class of inflationary solutions to the standard cosmological problems (horizon, flatness, monopole,...), based on a modification of old inflation. These models do not require a potential which satisfies the normal inflationary slow-roll conditions. Our universe arises from a single tunneling event as the inflaton leaves the false vacuum. Subsequent dynamics (arising from either the oscillations of the inflaton field or thermal effects) keep a second field trapped in a false minimum, resulting in an evanescent period of inflation (with roughly 50 e-foldings) inside the bubble. This easily allows the bubble to grow sufficiently large to contain our present horizon volume. Reheating is accomplished when the inflaton driving the last stage of inflation rolls down to the true vacuum, and adiabatic density perturbations arise from moduli-dependent Yukawa couplings of the inflaton to matter fields. Our scenario has several robust predictions, including virtual absence of gravity waves, a possible absence of tilt in scalar perturbations, and a higher degree of non-Gaussianity than other models. It also naturally incorporates a solution to the cosmological moduli problem.
Low-ℓ power suppression in punctuated inflation
International Nuclear Information System (INIS)
Qureshi, Mussadiq H.; Iqbal, Asif; Malik, Manzoor A.; Souradeep, Tarun
2017-01-01
Motivated by Planck confirmation of an anomalously low value of the CMB temperature fluctuations up to multipole ℓ < 40, we in this paper try to explain such feature by investigating case of punctuated inflation scenario. This form of inflation potential is inspired by Minimal Super-symmetric Standard Model (MSSM) wherein suppression of curvature perturbation power at large scales is produced by introducing period of fast-roll phase of the inflation sandwiched between two stages of slow-roll phase. We apply Markov Chain Monte Carlo analysis to determine posterior distribution and the best fit values of the model parameters using recent WMAP9 and Planck data. We show that WMAP9 and Planck results are consistent with each other and that with Planck data we obtain tighter constraints for punctuated inflation parameters. We find that punctuated inflation leads to better fit in CMB data compared to simple power law model. The improvement in the fit to the WMAP9 data is Δ χ 2 ∼ 3.6 and for Planck the improvement is Δ χ 2 ∼ 5.4. We find that AIC does not discriminate between punctuated inflation and simple power law model for WMAP9 data. However, for Planck data we find that punctuated inflation is moderately preferred over a simple power law model.
Seven lessons from manyfield inflation in random potentials
International Nuclear Information System (INIS)
Dias, Mafalda; Frazer, Jonathan; Marsh, M.C. David
2017-06-01
We study inflation in models with many interacting fields subject to randomly generated scalar potentials. We use methods from non-equilibrium random matrix theory to construct the potentials and an adaption of the 'transport method' to evolve the two-point correlators during inflation. This construction allows, for the first time, for an explicit study of models with up to 100 interacting fields supporting a period of 'approximately saddle-point' inflation. We determine the statistical predictions for observables by generating over 30,000 models with 2-100 fields supporting at least 60 efolds of inflation. These studies lead us to seven lessons: i) Manyfield inflation is not single-field inflation, ii) The larger the number of fields, the simpler and sharper the predictions, iii) Planck compatibility is not rare, but future experiments may rule out this class of models, iv) The smoother the potentials, the sharper the predictions, v) Hyperparameters can transition from stiff to sloppy, vi) Despite tachyons, isocurvature can decay, vii) Eigenvalue repulsion drives the predictions. We conclude that many of the 'generic predictions' of single-field inflation can be emergent features of complex inflation models.
Seven lessons from manyfield inflation in random potentials
Energy Technology Data Exchange (ETDEWEB)
Dias, Mafalda; Frazer, Jonathan [DESY Hamburg (Germany). Theory Group; Marsh, M.C. David [Cambridge Univ. (United Kingdom). Dept. of Appllied Mathematics and Theoretical Physics
2017-06-15
We study inflation in models with many interacting fields subject to randomly generated scalar potentials. We use methods from non-equilibrium random matrix theory to construct the potentials and an adaption of the 'transport method' to evolve the two-point correlators during inflation. This construction allows, for the first time, for an explicit study of models with up to 100 interacting fields supporting a period of 'approximately saddle-point' inflation. We determine the statistical predictions for observables by generating over 30,000 models with 2-100 fields supporting at least 60 efolds of inflation. These studies lead us to seven lessons: i) Manyfield inflation is not single-field inflation, ii) The larger the number of fields, the simpler and sharper the predictions, iii) Planck compatibility is not rare, but future experiments may rule out this class of models, iv) The smoother the potentials, the sharper the predictions, v) Hyperparameters can transition from stiff to sloppy, vi) Despite tachyons, isocurvature can decay, vii) Eigenvalue repulsion drives the predictions. We conclude that many of the 'generic predictions' of single-field inflation can be emergent features of complex inflation models.
Does Education Corrupt? Theories of Grade Inflation
Oleinik, Anton
2009-01-01
Several theories of grade inflation are discussed in this review article. It is argued that grade inflation results from the substitution of criteria specific to the search for truth by criteria of quality control generated outside of academia. Particular mechanisms of the grade inflation that occurs when a university is transformed into a…
Oil price pass-through into inflation
International Nuclear Information System (INIS)
Chen, Shiu-Sheng
2009-01-01
This paper uses data from 19 industrialized countries to investigate oil price pass-through into inflation across countries and over time. A time-varying pass-through coefficient is estimated and the determinants of the recent declining effects of oil shocks on inflation are investigated. The appreciation of the domestic currency, a more active monetary policy in response to inflation, and a higher degree of trade openness are found to explain the decline in oil price pass-through. (author)
The chaotic regime of D-term inflation
Energy Technology Data Exchange (ETDEWEB)
Buchmüller, W. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Domcke, V. [SISSA/INFN, Via Bonomea 265, 34136 Trieste (Italy); Schmitz, K., E-mail: wilfried.buchmueller@desy.de, E-mail: valerie.domcke@sissa.it, E-mail: kai.schmitz@ipmu.jp [Kavli IPMU (WPI), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa (Japan)
2014-11-01
We consider D-term inflation for small couplings of the inflaton to matter fields. Standard hybrid inflation then ends at a critical value of the inflaton field that exceeds the Planck mass. During the subsequent waterfall transition the inflaton continues its slow-roll motion, whereas the waterfall field rapidly grows by quantum fluctuations. Beyond the decoherence time, the waterfall field becomes classical and approaches a time-dependent minimum, which is determined by the value of the inflaton field and the self-interaction of the waterfall field. During the final stage of inflation, the effective inflaton potential is essentially quadratic, which leads to the standard predictions of chaotic inflation. The model illustrates how the decay of a false vacuum of GUT-scale energy density can end in a period of 'chaotic inflation'.
The chaotic regime of D-term inflation
Energy Technology Data Exchange (ETDEWEB)
Buchmueller, W. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Domcke, V. [SISSA/INFN, Triest (Italy); Schmitz, K. [Kavli IPMU (WPI), Kashiwa (Japan)
2014-08-15
We consider D-term inflation for small couplings of the inflaton to matter fields. Standard hybrid inflation then ends at a critical value of the inflaton field that exceeds the Planck mass. During the subsequent waterfall transition the inflaton continues its slow-roll motion, whereas the waterfall field rapidly grows by quantum fluctuations. Beyond the decoherence time, the waterfall field becomes classical and approaches a time-dependent minimum, which is determined by the value of the inflaton field and the self-interaction of the waterfall field. During the final stage of inflation, the effective inflaton potential is essentially quadratic, which leads to the standard predictions of chaotic inflation. The model illustrates how the decay of a false vacuum of GUT-scale energy density can end in a period of 'chaotic inflation'.
The chaotic regime of D-term inflation
International Nuclear Information System (INIS)
Buchmueller, W.; Domcke, V.; Schmitz, K.
2014-08-01
We consider D-term inflation for small couplings of the inflaton to matter fields. Standard hybrid inflation then ends at a critical value of the inflaton field that exceeds the Planck mass. During the subsequent waterfall transition the inflaton continues its slow-roll motion, whereas the waterfall field rapidly grows by quantum fluctuations. Beyond the decoherence time, the waterfall field becomes classical and approaches a time-dependent minimum, which is determined by the value of the inflaton field and the self-interaction of the waterfall field. During the final stage of inflation, the effective inflaton potential is essentially quadratic, which leads to the standard predictions of chaotic inflation. The model illustrates how the decay of a false vacuum of GUT-scale energy density can end in a period of 'chaotic inflation'.
The chaotic regime of D-term inflation
International Nuclear Information System (INIS)
Buchmüller, W.; Domcke, V.; Schmitz, K.
2014-01-01
We consider D-term inflation for small couplings of the inflaton to matter fields. Standard hybrid inflation then ends at a critical value of the inflaton field that exceeds the Planck mass. During the subsequent waterfall transition the inflaton continues its slow-roll motion, whereas the waterfall field rapidly grows by quantum fluctuations. Beyond the decoherence time, the waterfall field becomes classical and approaches a time-dependent minimum, which is determined by the value of the inflaton field and the self-interaction of the waterfall field. During the final stage of inflation, the effective inflaton potential is essentially quadratic, which leads to the standard predictions of chaotic inflation. The model illustrates how the decay of a false vacuum of GUT-scale energy density can end in a period of 'chaotic inflation'
The chaotic regime of D-term inflation
Buchmüller, W.; Domcke, V.; Schmitz, K.
2014-11-01
We consider D-term inflation for small couplings of the inflaton to matter fields. Standard hybrid inflation then ends at a critical value of the inflaton field that exceeds the Planck mass. During the subsequent waterfall transition the inflaton continues its slow-roll motion, whereas the waterfall field rapidly grows by quantum fluctuations. Beyond the decoherence time, the waterfall field becomes classical and approaches a time-dependent minimum, which is determined by the value of the inflaton field and the self-interaction of the waterfall field. During the final stage of inflation, the effective inflaton potential is essentially quadratic, which leads to the standard predictions of chaotic inflation. The model illustrates how the decay of a false vacuum of GUT-scale energy density can end in a period of `chaotic inflation'.
Interest and Inflation Risk: Investor Behavior
Directory of Open Access Journals (Sweden)
María de la O eGonzález
2016-03-01
Full Text Available We examine investor behavior under interest and inflation risk in different scenarios. To that end, we analyze the relation between stock returns and unexpected changes in nominal and real interest rates and inflation for the US stock market. This relation is examined in detail by breaking the results down from the US stock market level to sector, sub-sector and to individual industries as the ability of different industries to absorb unexpected changes in interest rates and inflation can vary by industry and by contraction and expansion sub-periods. While most significant relations are conventionally negative, some are consistently positive. This suggests some relevant implications on investor behavior. Thus, investments in industries with this positive relation can form a safe haven from unexpected changes in real and nominal interest rates. Gold has an insignificant beta during recessionary conditions hinting that Gold can be a safe haven during recessions. However, Gold also has a consistent negative relation to unexpected changes in inflation thereby damaging the claim that Gold is a hedge against inflation.
Interest and Inflation Risk: Investor Behavior
González, María de la O; Jareño, Francisco; Skinner, Frank S.
2016-01-01
We examine investor behavior under interest and inflation risk in different scenarios. To that end, we analyze the relation between stock returns and unexpected changes in nominal and real interest rates and inflation for the US stock market. This relation is examined in detail by breaking the results down from the US stock market level to sector, sub-sector, and to individual industries as the ability of different industries to absorb unexpected changes in interest rates and inflation can vary by industry and by contraction and expansion sub-periods. While most significant relations are conventionally negative, some are consistently positive. This suggests some relevant implications on investor behavior. Thus, investments in industries with this positive relation can form a safe haven from unexpected changes in real and nominal interest rates. Gold has an insignificant beta during recessionary conditions hinting that Gold can be a safe haven during recessions. However, Gold also has a consistent negative relation to unexpected changes in inflation thereby damaging the claim that Gold is a hedge against inflation. PMID:27047418
Interest and Inflation Risk: Investor Behavior.
González, María de la O; Jareño, Francisco; Skinner, Frank S
2016-01-01
We examine investor behavior under interest and inflation risk in different scenarios. To that end, we analyze the relation between stock returns and unexpected changes in nominal and real interest rates and inflation for the US stock market. This relation is examined in detail by breaking the results down from the US stock market level to sector, sub-sector, and to individual industries as the ability of different industries to absorb unexpected changes in interest rates and inflation can vary by industry and by contraction and expansion sub-periods. While most significant relations are conventionally negative, some are consistently positive. This suggests some relevant implications on investor behavior. Thus, investments in industries with this positive relation can form a safe haven from unexpected changes in real and nominal interest rates. Gold has an insignificant beta during recessionary conditions hinting that Gold can be a safe haven during recessions. However, Gold also has a consistent negative relation to unexpected changes in inflation thereby damaging the claim that Gold is a hedge against inflation.
CMB spectral distortion constraints on thermal inflation
Energy Technology Data Exchange (ETDEWEB)
Cho, Kihyun; Stewart, Ewan D. [Department of Physics, KAIST, Daejeon 34141 (Korea, Republic of); Hong, Sungwook E. [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of); Zoe, Heeseung, E-mail: cho_physics@kaist.ac.kr, E-mail: heezoe@dgist.ac.kr, E-mail: jcap@profstewart.org, E-mail: heezoe@dgist.ac.kr [School of Undergraduate Studies, College of Transdisciplinary Studies, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988 (Korea, Republic of)
2017-08-01
Thermal inflation is a second epoch of exponential expansion at typical energy scales V {sup 1/4} ∼ 10{sup 6} {sup ∼} {sup 8} GeV. If the usual primordial inflation is followed by thermal inflation, the primordial power spectrum is only modestly redshifted on large scales, but strongly suppressed on scales smaller than the horizon size at the beginning of thermal inflation, k > k {sub b} = a {sub b} H {sub b}. We calculate the spectral distortion of the cosmic microwave background generated by the dissipation of acoustic waves in this context. For k {sub b} || 10{sup 3} Mpc{sup −1}, thermal inflation results in a large suppression of the μ-distortion amplitude, predicting that it falls well below the standard value of μ ≅ 2× 10{sup −8}. Thus, future spectral distortion experiments, similar to PIXIE, can place new limits on the thermal inflation scenario, constraining k {sub b} ∼> 10{sup 3} Mpc{sup −1} if μ ≅ 2× 10{sup −8} were found.
Effects of thermal inflation on small scale density perturbations
Energy Technology Data Exchange (ETDEWEB)
Hong, Sungwook E. [School of Physics, Korea Institute for Advanced Study, 85 Hoegiro, Seoul 130-722 (Korea, Republic of); Lee, Hyung-Joo; Lee, Young Jae; Stewart, Ewan D. [Department of Physics, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-338 (Korea, Republic of); Zoe, Heeseung, E-mail: swhong@kias.re.kr, E-mail: ohsk111@kaist.ac.kr, E-mail: noasac@kaist.ac.kr, E-mail: jcap@profstewart.org, E-mail: heezoe@dgist.ac.kr [School of Basic Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno jungang-daero, Daegu 711-873 (Korea, Republic of)
2015-06-01
In cosmological scenarios with thermal inflation, extra eras of moduli matter domination, thermal inflation and flaton matter domination exist between primordial inflation and the radiation domination of Big Bang nucleosynthesis. During these eras, cosmological perturbations on small scales can enter and re-exit the horizon, modifying the power spectrum on those scales. The largest modified scale, k{sub b}, touches the horizon size when the expansion changes from deflation to inflation at the transition from moduli domination to thermal inflation. We analytically calculate the evolution of perturbations from moduli domination through thermal inflation and evaluate the curvature perturbation on the constant radiation density hypersurface at the end of thermal inflation to determine the late time curvature perturbation. Our resulting transfer function suppresses the power spectrum by a factor 0∼ 5 at k >> k{sub b}, with k{sub b} corresponding to anywhere from megaparsec to subparsec scales depending on the parameters of thermal inflation. Thus, thermal inflation might be constrained or detected by small scale observations such as CMB distortions or 21cm hydrogen line observations.
CERN. Geneva
2015-01-01
After reviewing the nice properties of Higgs inflation and some of its problems, I will discuss a simple unitarization of the scenario that is genuinely weakly coupled up to Planckian energies. A large non-minimal coupling between the Higgs and the Ricci curvature is induced dynamically at intermediate energies, as a simple ratio of mass scales. Inflationary dynamics is not dominated by the Higgs field, but 'Higgs inflation' arises as an approximate 'mirage' picture of the true dynamics. I will speculate on the generality of this phenomenon and show that, if Higgs-inflation arises as an effective description, the details of the UV completion are necessary to extract robust quantitative predictions.
Inflatable Antennas Support Emergency Communication
2010-01-01
Glenn Research Center awarded Small Business Innovation Research (SBIR) contracts to ManTech SRS Technologies, of Newport Beach, California, to develop thin film inflatable antennas for space communication. With additional funding, SRS modified the concepts for ground-based inflatable antennas. GATR (Ground Antenna Transmit and Receive) Technologies, of Huntsville, Alabama, licensed the technology and refined it to become the world s first inflatable antenna certified by the Federal Communications Commission. Capable of providing Internet access, voice over Internet protocol, e-mail, video teleconferencing, broadcast television, and other high-bandwidth communications, the systems have provided communication during the wildfires in California, after Hurricane Katrina in Mississippi, and following the 2010 Haiti earthquake.
Single-superfield helical-phase inflation
Energy Technology Data Exchange (ETDEWEB)
Ketov, Sergei V., E-mail: ketov@tmu.ac.jp [Department of Physics, Tokyo Metropolitan University, Minami-ohsawa 1-1, Hachioji-shi, Tokyo 192-0397 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (IPMU), The University of Tokyo, Chiba 277-8568 (Japan); Institute of Physics and Technology, Tomsk Polytechnic University, 30 Lenin Ave., Tomsk 634050 (Russian Federation); Terada, Takahiro, E-mail: takahiro@hep-th.phys.s.u-tokyo.ac.jp [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Deutsches Elektronen-Synchrotron (DESY), 22607 Hamburg (Germany)
2016-01-10
Large-field inflation in supergravity requires the approximate global symmetry needed to protect flatness of the scalar potential. In helical-phase inflation, the U(1) symmetry of the Kähler potential is assumed, the phase part of the complex scalar of a chiral superfield plays the role of inflaton, and the radial part is strongly stabilized. The original model of helical phase inflation, proposed by Li, Li and Nanopoulos (LLN), employs an extra (stabilizer) superfield. We propose a more economical new class of the helical phase inflationary models without a stabilizer superfield. As the specific examples, the quadratic, the natural, and the Starobinsky-type inflationary models are studied in our approach.
Hybrid inflation in the complex plane
International Nuclear Information System (INIS)
Buchmueller, W.; Domcke, V.; Kamada, K.; Schmitz, K.
2014-04-01
Supersymmetric hybrid inflation is an exquisite framework to connect inflationary cosmology to particle physics at the scale of grand unification. Ending in a phase transition associated with spontaneous symmetry breaking, it can naturally explain the generation of entropy, matter and dark matter. Coupling F-term hybrid inflation to soft supersymmetry breaking distorts the rotational invariance in the complex inflaton plane - an important fact, which has been neglected in all previous studies. Based on the δN formalism, we analyze the cosmological perturbations for the first time in the full two-field model, also taking into account the fast-roll dynamics at and after the end of inflation. As a consequence of the two-field nature of hybrid inflation, the predictions for the primordial fluctuations depend not only on the parameters of the Lagrangian, but are eventually fixed by the choice of the inflationary trajectory. Recognizing hybrid inflation as a two-field model resolves two shortcomings often times attributed to it: The fine-tuning problem of the initial conditions is greatly relaxed and a spectral index in accordance with the PLANCK data can be achieved in a large part of the parameter space without the aid of supergravity corrections. Our analysis can be easily generalized to other (including large-field) scenarios of inflation in which soft supersymmetry breaking transforms an initially single-field model into a multi-field model.
On the burst of branched polymer melts during inflation
DEFF Research Database (Denmark)
Rasmussen, Henrik K.; Yu, Kaijia
2008-01-01
Two molten low-density polyethylene melts, shaped as plates, have been inflated into a circular cylinder during isothermal conditions. Lowering the inflation rates allow the plates to be inflated into a larger volume of the cylinder before bursting. Numerical simulations of the inflations have been...
Delaying the waterfall transition in warm hybrid inflation
Bastero-Gil, Mar; Berera, Arjun; Metcalf, Thomas P.; Rosa, João G.
2014-01-01
We analyze the dynamics and observational predictions of supersymmetric hybrid inflation in the warm regime, where dissipative effects are mediated by the waterfall fields and their subsequent decay into light degrees of freedom. This produces a quasi-thermal radiation bath with a slowly-varying temperature during inflation and further damps the inflaton's motion, thus prolonging inflation. As in the standard supercooled scenario, inflation ends when the waterfall fields become tachyonic and ...
Theories of inflation and conformal transformations
International Nuclear Information System (INIS)
Kalara, S.; Kaloper, N.; Olive, K.A.
1990-01-01
We show that several different theories of inflation including R 2 , Brans-Dicke, and induced-gravity inflation are all related to generalized or power-law inflation by means of conformal transformations. These theories all involve non-standard gravity, and the use of conformal transformations allows one to obtain standard inflationary predictions such as the expansion time-scale, reheating and density perturbations in each case very simply. We also discuss the possibilities of this method to be applied to string theory. (orig.)
When Parents’ Praise Inflates, Children's Self-Esteem Deflates
Brummelman, Eddie; Nelemans, Stefanie A.; Thomaes, Sander; Orobio De Castro, Bram
2017-01-01
Western parents often give children overly positive, inflated praise. One perspective holds that inflated praise sets unattainable standards for children, eventually lowering children's self-esteem (self-deflation hypothesis). Another perspective holds that children internalize inflated praise to
Towards matter inflation in heterotic string theory
International Nuclear Information System (INIS)
Antusch, Stefan; Erdmenger, Johanna; Halter, Sebastian; Dutta, Koushik
2011-02-01
Recently, a class of inflation models in supergravity with gauge non-singlet matter fields as the inflaton has been proposed. It is based on a 'tribrid' structure in the superpotential and on a 'Heisenberg symmetry' for solving the η-problem. We suggest that a generalization of this model class may be suitable for realising inflation in heterotic orbifold compactifications, where the Heisenberg symmetry is a property of the tree-level Kaehler potential of untwisted matter fields. We discuss moduli stabilization in this setup and propose a mechanism to stabilize the modulus associated to the inflaton, which respects the symmetry in the large radius limit. Inflation ends via a waterfall phase transition, as in hybrid inflation. We give conditions which have to be satisfied for realising inflation along these lines in the matter sector of heterotic orbifolds. (orig.)
A viable D-term hybrid inflation model
Kadota, Kenji; Kobayashi, Tatsuo; Sumita, Keigo
2017-11-01
We propose a new model of the D-term hybrid inflation in the framework of supergravity. Although our model introduces, analogously to the conventional D-term inflation, the inflaton and a pair of scalar fields charged under a U(1) gauge symmetry, we study the logarithmic and exponential dependence on the inflaton field, respectively, for the Kähler and superpotential. This results in a characteristic one-loop scalar potential consisting of linear and exponential terms, which realizes the small-field inflation dominated by the Fayet-Iliopoulos term. With the reasonable values for the coupling coefficients and, in particular, with the U(1) gauge coupling constant comparable to that of the Standard Model, our D-term inflation model can solve the notorious problems in the conventional D-term inflation, namely, the CMB constraints on the spectral index and the generation of cosmic strings.
Classical anisotropies in models of open inflation
International Nuclear Information System (INIS)
Garriga, J.; Mukhanov, V.F.
1997-01-01
In the simplest model of open inflation there are two inflaton fields decoupled from each other. One of them, the tunneling field, produces a first stage of inflation which prepares the ground for the nucleation of a highly symmetric bubble. The other, a free field, drives a second period of slow-roll inflation inside the bubble. However, the second field also evolves during the first stage of inflation, which to some extent breaks the needed symmetry. We show that this generates large supercurvature anisotropies which, together with the results of Tanaka and Sasaki, rule out this class of simple models (unless, of course, Ω 0 is sufficiently close to 1). The problem does not arise in modified models where the second field does not evolve in the first stage of inflation. copyright 1997 The American Physical Society
Towards matter inflation in heterotic string theory
Energy Technology Data Exchange (ETDEWEB)
Antusch, Stefan; Erdmenger, Johanna; Halter, Sebastian [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany); Dutta, Koushik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2011-02-15
Recently, a class of inflation models in supergravity with gauge non-singlet matter fields as the inflaton has been proposed. It is based on a 'tribrid' structure in the superpotential and on a 'Heisenberg symmetry' for solving the {eta}-problem. We suggest that a generalization of this model class may be suitable for realising inflation in heterotic orbifold compactifications, where the Heisenberg symmetry is a property of the tree-level Kaehler potential of untwisted matter fields. We discuss moduli stabilization in this setup and propose a mechanism to stabilize the modulus associated to the inflaton, which respects the symmetry in the large radius limit. Inflation ends via a waterfall phase transition, as in hybrid inflation. We give conditions which have to be satisfied for realising inflation along these lines in the matter sector of heterotic orbifolds. (orig.)
46 CFR 506.3 - Civil monetary penalty inflation adjustment.
2010-10-01
... 46 Shipping 9 2010-10-01 2010-10-01 false Civil monetary penalty inflation adjustment. 506.3... PENALTY INFLATION ADJUSTMENT § 506.3 Civil monetary penalty inflation adjustment. The Commission shall... each civil monetary penalty provided by law within the jurisdiction of the Commission by the inflation...
Helical Phase Inflation and Monodromy in Supergravity Theory
Directory of Open Access Journals (Sweden)
Tianjun Li
2015-01-01
Full Text Available We study helical phase inflation which realizes “monodromy inflation” in supergravity theory. In the model, inflation is driven by the phase component of a complex field whose potential possesses helicoid structure. We construct phase monodromy based on explicitly breaking global U(1 symmetry in the superpotential. By integrating out heavy fields, the phase monodromy from single complex scalar field is realized and the model fulfills natural inflation. The phase-axion alignment is achieved from explicitly symmetry breaking and gives super-Planckian phase decay constant. The F-term scalar potential provides strong field stabilization for all the scalars except inflaton, which is protected by the approximate global U(1 symmetry. Besides, we show that helical phase inflation can be naturally realized in no-scale supergravity with SU(2,1/SU(2×U(1 symmetry since the supergravity setup needed for phase monodromy is automatically provided in the no-scale Kähler potential. We also demonstrate that helical phase inflation can be reduced to another well-known supergravity inflation model with shift symmetry. Helical phase inflation is free from the UV-sensitivity problem although there is super-Planckian field excursion, and it suggests that inflation can be effectively studied based on supersymmetric field theory while a UV-completed framework is not prerequisite.
Low-ℓ power suppression in punctuated inflation
Energy Technology Data Exchange (ETDEWEB)
Qureshi, Mussadiq H.; Iqbal, Asif; Malik, Manzoor A. [Department of Physics, University of Kashmir, Hazratbal, Srinagar, Jammu and Kashmir 190006 (India); Souradeep, Tarun, E-mail: mussadiqqureshi111@gmail.com, E-mail: asifiqbal@kashmiruniversity.net, E-mail: mmalik@kashmiruniversity.ac.in, E-mail: tarun@iucaa.in [Inter-University Center for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India)
2017-04-01
Motivated by Planck confirmation of an anomalously low value of the CMB temperature fluctuations up to multipole ℓ < 40, we in this paper try to explain such feature by investigating case of punctuated inflation scenario. This form of inflation potential is inspired by Minimal Super-symmetric Standard Model (MSSM) wherein suppression of curvature perturbation power at large scales is produced by introducing period of fast-roll phase of the inflation sandwiched between two stages of slow-roll phase. We apply Markov Chain Monte Carlo analysis to determine posterior distribution and the best fit values of the model parameters using recent WMAP9 and Planck data. We show that WMAP9 and Planck results are consistent with each other and that with Planck data we obtain tighter constraints for punctuated inflation parameters. We find that punctuated inflation leads to better fit in CMB data compared to simple power law model. The improvement in the fit to the WMAP9 data is Δ χ{sup 2} ∼ 3.6 and for Planck the improvement is Δ χ{sup 2} ∼ 5.4. We find that AIC does not discriminate between punctuated inflation and simple power law model for WMAP9 data. However, for Planck data we find that punctuated inflation is moderately preferred over a simple power law model.
Sneutrino warm inflation in the minimal supersymmetric model
International Nuclear Information System (INIS)
Bastero-Gil, Mar; Berera, Arjun
2005-01-01
The model of RH neutrino fields coupled to the MSSM is shown to yield a large parameter regime of warm inflation. In the strong dissipative regime, it is shown that inflation, driven by a single sneutrino field, occurs with all field amplitudes below the Planck scale. Analysis is also made of leptogenesis, neutrino mass generation and gravitino constraints. A new warm inflation scenario is purposed in which one scalar field drives a period of warm inflation and a second field drives a subsequent phase of reheating. Such a model is able to reduce the final temperature after inflation, thus helping to mitigate gravitino constraints
Inflation in a shear-or curvature-dominated universe
International Nuclear Information System (INIS)
Steigman, G.; Turner, M.S.
1983-01-01
We show that new inflation occurs even if the universe is shear-or (negative) curvature-dominated when the phase transition begins. In such situations the size of a causally coherent region, after inflation, is only slightly smaller (by powers, but not by exponential factors) than the usual result. The creation and evolution of density perturbations is unaffected. This result is marked contrast to 'old' inflation, where shear- or curvature-domination could quench inflation. (orig.)
The properties of inflation expectations: Evidence for India
Naresh Kumar Sharma; Motilal Bicchal
2018-01-01
Empirical inferences about particular forms of agents’ inflation expectations are crucial for the conduct of monetary policy. This paper is an attempt to explore the properties of the Reserve Bank of India’s survey data of households’ inflation expectations. The paper shows that survey respondents do not form expectations rationally, regardless of the reference measures of inflation used. Further, results indicate that inflation expectations are formed purely in backward-looking manner, sugge...
26 CFR 1.1275-7 - Inflation-indexed debt instruments.
2010-04-01
... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Inflation-indexed debt instruments. 1.1275-7... Inflation-indexed debt instruments. (a) Overview. This section provides rules for the Federal income tax treatment of an inflation-indexed debt instrument. If a debt instrument is an inflation-indexed debt...
2014-12-01
have to do so in the water. Shortly thereafter, the Survival Research Unit at CAMI devel- oped a prototype life preserver, with a primary goal of...calculate the various donning function times, as defined below. These were entered into IBM SPSS ® version 21 for statistical analysis. “TSO Test Time...inflation tubes, manual inflation triggering devices with pull tabs and CO2 cartridges, and designed to be reversible. The experimental life preserver
Inflation gifts and endogenous growth through learning-by-doing
Andrea Vaona
2013-01-01
We investigate the link between inflation, growth and unemployment nesting a model of fair wages into one of endogenous growth of learning by doing and assuming that firms protect wages' purchasing power against inflation in exchange of worker's effort. Unemployment decreases with higher inflation and real growth rates. These effects tends to vanish as inflation and growth increase. Depending on the assumptions on learning-by-doing mechanisms, the effect of inflation on growth can be either n...
Macroeconomic susceptibility, inflation, and aggregate supply
Hawkins, Raymond J.
2017-03-01
We unify aggregate-supply dynamics as a time-dependent susceptibility-mediated relationship between inflation and aggregate economic output. In addition to representing well various observations of inflation-output dynamics this parsimonious formalism provides a straightforward derivation of popular representations of aggregate-supply dynamics and a natural basis for economic-agent expectations as an element of inflation formation. Our formalism also illuminates questions of causality and time-correlation that challenge central banks for whom aggregate-supply dynamics is a key constraint in their goal of achieving macroeconomic stability.
Inflation as de Sitter instability
Energy Technology Data Exchange (ETDEWEB)
Cadoni, Mariano; Franzin, Edgardo [Universita di Cagliari, Cittadella Universitaria, Dipartimento di Fisica, Monserrato (Italy); INFN, Sezione di Cagliari, Monserrato (Italy); Mignemi, Salvatore [INFN, Sezione di Cagliari, Monserrato (Italy); Universita di Cagliari, Dipartimento di Matematica e Informatica, Cagliari (Italy)
2016-09-15
We consider cosmological inflation generated by a scalar field slowly rolling off from a de Sitter maximum of its potential. The models belong to the class of hilltop models and represent the most general model of this kind in which the scalar potential can be written as the sum of two exponentials. The minimally coupled Einstein-scalar gravity theory obtained in this way is the cosmological version of a two-scale generalization of known holographic models, allowing for solitonic solutions interpolating between an AdS spacetime in the infrared and scaling solutions in the ultraviolet. We then investigate cosmological inflation in the slow-roll approximation. Our model reproduces correctly, for a wide range of its parameters, the most recent experimental data for the power spectrum of primordial perturbations. Moreover, it predicts inflation at energy scales of four to five orders of magnitude below the Planck scale. At the onset of inflation, the mass of the tachyonic excitation, i.e. of the inflaton, turns out to be seven to eight orders of magnitude smaller than the Planck mass. (orig.)
Dark energy in hybrid inflation
International Nuclear Information System (INIS)
Gong, Jinn-Ouk; Kim, Seongcheol
2007-01-01
The situation that a scalar field provides the source of the accelerated expansion of the Universe while rolling down its potential is common in both the simple models of the primordial inflation and the quintessence-based dark energy models. Motivated by this point, we address the possibility of causing the current acceleration via the primordial inflation using a simple model based on hybrid inflation. We trigger the onset of the motion of the quintessence field via the waterfall field, and find that the fate of the Universe depends on the true vacuum energy determined by choosing the parameters. We also briefly discuss the variation of the equation of state and the possible implementation of our scenario in supersymmetric theories
Energy Technology Data Exchange (ETDEWEB)
Barbón, J.L.F.; Casas, J.A. [IFT-UAM/CSIC, Universidad Autónoma de Madrid,C/Nicolás Cabrera 13, 28049 Madrid (Spain); Elias-Miró, J. [Departament de Física/IFAE, Universitat Autònoma de Barcelona,Edifici Cn, 08193 Bellaterra, Barcelona (Spain); Espinosa, J.R. [ICREA/IFAE, Universitat Autònoma de Barcelona,Edifici Cn, 08193 Bellaterra, Barcelona (Spain)
2015-09-04
We discuss a simple unitarization of Higgs inflation that is genuinely weakly coupled up to Planckian energies. A large non-minimal coupling between the Higgs and the Ricci curvature is induced dynamically at intermediate energies, as a simple ratio of mass scales. Despite not being dominated by the Higgs field, inflationary dynamics simulates the ‘Higgs inflation’ one would get by blind extrapolation of the low-energy effective Lagrangian, at least qualitatively. Hence, Higgs inflation arises as an approximate ‘mirage’ picture of the true dynamics. We further speculate on the generality of this phenomenon and show that, if Higgs-inflation arises as an effective description, the details of the UV completion are necessary to extract robust quantitative predictions.
International Nuclear Information System (INIS)
Barbón, J.L.F.; Casas, J.A.; Elias-Miró, J.; Espinosa, J.R.
2015-01-01
We discuss a simple unitarization of Higgs inflation that is genuinely weakly coupled up to Planckian energies. A large non-minimal coupling between the Higgs and the Ricci curvature is induced dynamically at intermediate energies, as a simple ratio of mass scales. Despite not being dominated by the Higgs field, inflationary dynamics simulates the ‘Higgs inflation’ one would get by blind extrapolation of the low-energy effective Lagrangian, at least qualitatively. Hence, Higgs inflation arises as an approximate ‘mirage’ picture of the true dynamics. We further speculate on the generality of this phenomenon and show that, if Higgs-inflation arises as an effective description, the details of the UV completion are necessary to extract robust quantitative predictions.
Inflation and Growth: Positive or Negative Relationship?
Berument, Hakan; Inamlik, Ali; Olgun, Hasan
This study has been motivated by two developments. Firstly, by the vast literature on the relationship between inflation and growth which is abundantly endowed with diverse theoretical explanations and contradictory evidence and by the unique experience of the Turkish economy with inflation and growth. A preliminary examination of the Turkish data pointed to a negative relation between inflation and growth. Moreover, there is a unanimous agreement among the students of the Turkish economy that many factors have contributed to inflation in this country. In view of these facts this paper employs a VAR model which will enable us to identify the sources of the shocks and control for external factors. In addition VAR models have a high predictive power and enable the researcher to observe the impulse response functions. The study employs Generalised Impulse Response analysis. In the empirical experiments oil prices, money supply, government spending and taxes have been taken as the most likely determinants of inflation. The study shows that there is a negative relationship between inflation and output growth in Turkey and that the underlying explanatory factor is the real exchange rate. This result is robust.
Plateau inflation in R-parity violating MSSM
Directory of Open Access Journals (Sweden)
Girish Kumar Chakravarty
2016-12-01
Full Text Available Inflation with plateau potentials give the best fit to the CMB observables as they predict tensor to scalar ratio stringently bounded by the observations from Planck and BICEP2/Keck. In supergravity models it is possible to obtain plateau potentials for scalar fields in the Einstein frame which can serve as the inflation potential by considering higher dimensional Planck suppressed operators and by the choice of non-canonical Kähler potentials. We construct a plateau inflation model in MSSM where the inflation occurs along a sneutrino-Higgs flat direction. A hidden sector Polonyi field is used for the breaking of supersymmetry after the end of the inflation. The proper choice of superpotential leads to strong stabilization of the Polonyi field, mZ2≫m3/22, which is required to solve the cosmological moduli problem. Also, the SUSY breaking results in a TeV scale gravitino mass and scalar masses and gives rise to bilinear and trilinear couplings of scalars which can be tested at the LHC. The sneutrino inflation field can be observed at the LHC as a TeV scale diphoton resonance like the one reported by CMS and ATLAS.
The impact of inflation uncertainty on interest rates
Cheong, Chongcheul; Kim, Gi-Hong; Podivinsky, Jan M.
2010-01-01
In this paper, the impact of inflation uncertainty on interest rates is investigated for the case of the U.S. three-month Treasury bill rate. We emphasize how consistentOLS estimation can be applied to an empirical equation which includes a proxy variable of inflation uncertainty measured by an ARCH-type model. A significant negative relationship between the two variables is provided. This evidence is contrasted with the view of the inflation risk premium in which inflation uncertainty positi...
Assisted inflation from geometric tachyon
International Nuclear Information System (INIS)
Panigrahi, Kamal L.; Singh, Harvendra
2007-01-01
We study the effect of rolling of N D3-branes in the vicinity of NS5-branes. We find out that this system coupled with the four dimensional gravity gives the slow roll assisted inflation of the scalar field theory. Once again this expectation is exactly similar to that of N-tachyon assisted inflation on unstable D-branes
Inflation in the standard cosmological model
Uzan, Jean-Philippe
2015-12-01
The inflationary paradigm is now part of the standard cosmological model as a description of its primordial phase. While its original motivation was to solve the standard problems of the hot big bang model, it was soon understood that it offers a natural theory for the origin of the large-scale structure of the universe. Most models rely on a slow-rolling scalar field and enjoy very generic predictions. Besides, all the matter of the universe is produced by the decay of the inflaton field at the end of inflation during a phase of reheating. These predictions can be (and are) tested from their imprint of the large-scale structure and in particular the cosmic microwave background. Inflation stands as a window in physics where both general relativity and quantum field theory are at work and which can be observationally studied. It connects cosmology with high-energy physics. Today most models are constructed within extensions of the standard model, such as supersymmetry or string theory. Inflation also disrupts our vision of the universe, in particular with the ideas of chaotic inflation and eternal inflation that tend to promote the image of a very inhomogeneous universe with fractal structure on a large scale. This idea is also at the heart of further speculations, such as the multiverse. This introduction summarizes the connections between inflation and the hot big bang model and details the basics of its dynamics and predictions. xml:lang="fr"
Chaotic inflation in models with flat directions
International Nuclear Information System (INIS)
Graziani, F.; Olive, K.
1989-01-01
We consider the chaotic inflationary scenario in models with flat directions. We find that unless the scalars along the flat directions have vacuum expectation values p or 10 14 M p 15 M p depending on the expectation values of the chaotic inflator, Ψ, one or two or more periods of inflation occur but with a resulting energy density perturbation δρ/ρ ≅ 10 -16 , far too small to be of any consequence for galaxy formation. Even with p only limited initial values of ≅ (3-200) M p result in inflation with reasonable density perturbations. Thus chaotic inflation in models with flat directions require rather special initial conditions. (orig.)
1984-01-01
Helicopter, Helicopter Cost Growth, Historical Cost, Historical Inflation R~ates, Indexes, Inflation ( Economic ), Methodology, Model, , Prices, Procurement...Producer Price Index and hourly: wace data were suzplied by the Kansas City Regional office of the Bureau of Labor Statistics, U.S. Department of Labor. The...most closely related commodities. To minimize the effect from related commodities which have relatively little economic impact, each price per pound
International Nuclear Information System (INIS)
Dimopoulos, Konstantinos; Lyth, David H.; Kohri, Kazunori; Matsuda, Tomohiro
2012-01-01
The primordial curvature perturbation ζ may be generated by some curvaton field σ, which is negligible during inflation and has more or less negligible interactions until it decays. In the current scenario, the curvaton starts to oscillate while its energy density ρσ is negligible. We explore the opposite scenario, in which ρσ drives a few e-folds of inflation before the oscillation begins. In this scenario for generating ζ it is exceptionally easy to solve the η problem; one just has to make the curvaton a string axion, with anomaly-mediated susy breaking which may soon be tested at the LHC. The observed spectral index n can be obtained with a potential V∝φ p for the first inflation; p = 1 or 2 is allowed by the current uncertainty in n but the improvement in accuracy promised by Planck may rule out p = 1. The predictions include (i) running n' ≅ 0.0026 (0.0013) for p = 1 (2) that will probably be observed, (ii) non-gaussianity parameter f NL ; ∼ −1 that may be observed, (iii) tensor fraction r is probably too small to ever observed
A Signature of Inflation from Dynamical Supersymmetry Breaking
Kinney, W H; Kinney, William H.; Riotto, Antonio
1998-01-01
In models of cosmological inflation motivated by dynamical supersymmetry breaking, the potential driving inflation may be characterized by inverse powers of a scalar field. These models produce observables similar to those typical of the hybrid inflation scenario: negligible production of tensor (gravitational wave) modes, and a blue scalar spectral index. In this short note, we show that, unlike standard hybrid inflation models, dynamical supersymmetric inflation (DSI) predicts a measurable deviation from a power-law spectrum of fluctuations, with a variation in the scalar spectral index $|dn / d(\\ln k)|$ may be as large as 0.05. DSI can be observationally distinguished from other hybrid models with cosmic microwave background measurements of the planned sensitivity of the ESA's Planck Surveyor.
Inflation from extra dimensions
International Nuclear Information System (INIS)
Barr, S.M.
1984-01-01
Recently there has been growing interest (1) in the possibility that the universe could have more than four dimensions. Aside from any light this may shed on problems in particle physics, if true it would undoubtedly have important implications for early cosmology. A rather speculative but very appealing possibility suggested by D. Sahdev and by E. Alvarez and B. Gavela is that the gravitational collapse of extra spatial dimensions could drive an inflation of ordinary space. This kind of inflationary cosmology would be quite different from the inflationary cosmologies now so intensively studied which are supposed to result from changes in vacuum energy during phase transitions in the early universe. In our work we examine the physics of these Kaluza-Klein inflationary cosmologies and come to three main conclusions. (1) It is desirable to have many extra dimensions, many being of order forty or fifty. (2) For models which give a realistically large inflation almost all of this inflation occurs in a period when quantum gravity is certainly important. This means that Einstein's equations cannot be used to calculate the details of this inflationary period. (3) Under plausible assumptions one may argue from the second law of thermodynamics that given appropriate initial conditions a large inflation will occur even when details of the inflationary phase cannot be calculated classically
A general framework of automorphic inflation
International Nuclear Information System (INIS)
Schimmrigk, Rolf
2016-01-01
Automorphic inflation is an application of the framework of automorphic scalar field theory, based on the theory of automorphic forms and representations. In this paper the general framework of automorphic and modular inflation is described in some detail, with emphasis on the resulting stratification of the space of scalar field theories in terms of the group theoretic data associated to the shift symmetry, as well as the automorphic data that specifies the potential. The class of theories based on Eisenstein series provides a natural generalization of the model of j-inflation considered previously.
A general framework of automorphic inflation
Energy Technology Data Exchange (ETDEWEB)
Schimmrigk, Rolf [Department of Physics, Indiana University at South Bend,1700 Mishawaka Ave. South Bend, IN 46634 (United States)
2016-05-24
Automorphic inflation is an application of the framework of automorphic scalar field theory, based on the theory of automorphic forms and representations. In this paper the general framework of automorphic and modular inflation is described in some detail, with emphasis on the resulting stratification of the space of scalar field theories in terms of the group theoretic data associated to the shift symmetry, as well as the automorphic data that specifies the potential. The class of theories based on Eisenstein series provides a natural generalization of the model of j-inflation considered previously.
Inflation in a closed universe
Ratra, Bharat
2017-11-01
To derive a power spectrum for energy density inhomogeneities in a closed universe, we study a spatially-closed inflation-modified hot big bang model whose evolutionary history is divided into three epochs: an early slowly-rolling scalar field inflation epoch and the usual radiation and nonrelativistic matter epochs. (For our purposes it is not necessary to consider a final dark energy dominated epoch.) We derive general solutions of the relativistic linear perturbation equations in each epoch. The constants of integration in the inflation epoch solutions are determined from de Sitter invariant quantum-mechanical initial conditions in the Lorentzian section of the inflating closed de Sitter space derived from Hawking's prescription that the quantum state of the universe only include field configurations that are regular on the Euclidean (de Sitter) sphere section. The constants of integration in the radiation and matter epoch solutions are determined from joining conditions derived by requiring that the linear perturbation equations remain nonsingular at the transitions between epochs. The matter epoch power spectrum of gauge-invariant energy density inhomogeneities is not a power law, and depends on spatial wave number in the way expected for a generalization to the closed model of the standard flat-space scale-invariant power spectrum. The power spectrum we derive appears to differ from a number of other closed inflation model power spectra derived assuming different (presumably non de Sitter invariant) initial conditions.
76 FR 74625 - Civil Monetary Penalties Inflation Adjustment
2011-12-01
...-2011] RIN 1125-AA69 Civil Monetary Penalties Inflation Adjustment AGENCIES: U.S. Customs and Border... adjust for inflation certain civil monetary penalties assessed under the Immigration and Nationality Act... assessed under the INA. The Federal Civil Penalties Inflation Adjustment Act of 1990 (Adjustment Act...
M-theory inflation from multi M5-brane dynamics
International Nuclear Information System (INIS)
Becker, Katrin; Becker, Melanie; Krause, Axel
2005-01-01
We derive inflation from M-theory on S 1 /Z 2 via the non-perturbative dynamics of N M5-branes. The open membrane instanton interactions between the M5-branes give rise to exponential potentials which are too steep for inflation individually but lead to inflation when combined together. The resulting type of inflation, known as assisted inflation, facilitates considerably the requirement of having all moduli, except the inflaton, stabilized at the beginning of inflation. During inflation the distances between the M5-branes, which correspond to the inflatons, grow until they reach the size of the S 1 /Z 2 orbifold. At this stage the M5-branes will reheat the universe by dissolving into the boundaries through small instanton transitions. Further flux and non-perturbative contributions become important at this late stage, bringing inflation to an end and stabilizing the moduli. We find that with moderate values for N, one obtains both a sufficient amount of e-foldings and the right size for the spectral index
Evading the Lyth bound in hybrid natural inflation
International Nuclear Information System (INIS)
Hebecker, A.; Kraus, S.C.; Westphal, Alexander
2013-05-01
Generically, the gravitational-wave or tensor-mode contribution to the primordial curvature spectrum of inflation is tiny if the field-range of the inflaton is much smaller than the Planck scale. We show that this pessimistic conclusion is naturally avoided in a rather broad class of small-field models. More specifically, we consider models where an axion-like shift symmetry keeps the inflaton potential flat (up to non-perturbative cosine-shaped modulations), but inflation nevertheless ends in a waterfall-regime, as is typical for hybrid inflation. In such hybrid natural inflation scenarios (examples are provided by Wilson line inflation and fluxbrane inflation), the slow-roll parameter ε can be sizable during an early period (relevant for the CMB spectrum). Subsequently, ε quickly becomes very small before the tachyonic instability eventually terminates the slow-roll regime. In this scenario, one naturally generates a considerable tensor-mode contribution in the curvature spectrum, collecting nevertheless the required amount of e-foldings during the final period of inflation. While non-observation of tensors by Planck is certainly not a problem, a discovery in the medium to long term future is realistic.
Evading the Lyth bound in hybrid natural inflation
Hebecker, A.; Kraus, S. C.; Westphal, A.
2013-12-01
Generically, the gravitational-wave or tensor-mode contribution to the primordial curvature spectrum of inflation is tiny if the field range of the inflaton is much smaller than the Planck scale. We show that this pessimistic conclusion is naturally avoided in a rather broad class of small-field models. More specifically, we consider models where an axionlike shift symmetry keeps the inflaton potential flat (up to nonperturbative cosine-shaped modulations), but inflation nevertheless ends in a waterfall regime, as is typical for hybrid inflation. In such hybrid natural inflation scenarios (examples are provided by Wilson line inflation and fluxbrane inflation), the slow-roll parameter ɛ can be sizable during an early period (relevant for the cosmic microwave background spectrum). Subsequently, ɛ quickly becomes very small before the tachyonic instability eventually terminates the slow-roll regime. In this scenario, one naturally generates a considerable tensor-mode contribution in the curvature spectrum, collecting nevertheless the required amount of e-foldings during the final period of inflation. While nonobservation of tensors by Planck is certainly not a problem, a discovery in the medium- to long-term future is realistic.
How likely are constituent quanta to initiate inflation?
Directory of Open Access Journals (Sweden)
Lasha Berezhiani
2015-10-01
Full Text Available We propose an intuitive framework for studying the problem of initial conditions in slow-roll inflation. In particular, we consider a universe at high, but sub-Planckian energy density and analyze the circumstances under which it is plausible for it to become dominated by inflated patches at late times, without appealing to the idea of self-reproduction. Our approach is based on defining a prior probability distribution for the constituent quanta of the pre-inflationary universe. To test the idea that inflation can begin under very generic circumstances, we make specific – yet quite general and well grounded – assumptions on the prior distribution. As a result, we are led to the conclusion that the probability for a given region to ignite inflation at sub-Planckian densities is extremely small. Furthermore, if one chooses to use the enormous volume factor that inflation yields as an appropriate measure, we find that the regions of the universe which started inflating at densities below the self-reproductive threshold nevertheless occupy a negligible physical volume in the present universe as compared to those domains that have never inflated.
Intermediate inflation from a non-canonical scalar field
Energy Technology Data Exchange (ETDEWEB)
Rezazadeh, K.; Karami, K. [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of); Karimi, P., E-mail: rezazadeh86@gmail.com, E-mail: KKarami@uok.ac.ir, E-mail: parvin.karimi67@yahoo.com [Center for Excellence in Astronomy and Astrophysics (CEAA-RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)
2015-09-01
We study the intermediate inflation in a non-canonical scalar field framework with a power-like Lagrangian. We show that in contrast with the standard canonical intermediate inflation, our non-canonical model is compatible with the observational results of Planck 2015. Also, we estimate the equilateral non-Gaussianity parameter which is in well agreement with the prediction of Planck 2015. Then, we obtain an approximation for the energy scale at the initial time of inflation and show that it can be of order of the Planck energy scale, i.e. M{sub P} ∼ 10{sup 18}GeV. We will see that after a short period of time, inflation enters in the slow-roll regime that its energy scale is of order M{sub P}/100 ∼ 10{sup 16}GeV and the horizon exit takes place in this energy scale. We also examine an idea in our non-canonical model to overcome the central drawback of intermediate inflation which is the fact that inflation never ends. We solve this problem without disturbing significantly the nature of the intermediate inflation until the time of horizon exit.
Evading the Lyth bound in hybrid natural inflation
Energy Technology Data Exchange (ETDEWEB)
Hebecker, A.; Kraus, S.C. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Westphal, Alexander [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany). Theory Group
2013-05-15
Generically, the gravitational-wave or tensor-mode contribution to the primordial curvature spectrum of inflation is tiny if the field-range of the inflaton is much smaller than the Planck scale. We show that this pessimistic conclusion is naturally avoided in a rather broad class of small-field models. More specifically, we consider models where an axion-like shift symmetry keeps the inflaton potential flat (up to non-perturbative cosine-shaped modulations), but inflation nevertheless ends in a waterfall-regime, as is typical for hybrid inflation. In such hybrid natural inflation scenarios (examples are provided by Wilson line inflation and fluxbrane inflation), the slow-roll parameter {epsilon} can be sizable during an early period (relevant for the CMB spectrum). Subsequently, {epsilon} quickly becomes very small before the tachyonic instability eventually terminates the slow-roll regime. In this scenario, one naturally generates a considerable tensor-mode contribution in the curvature spectrum, collecting nevertheless the required amount of e-foldings during the final period of inflation. While non-observation of tensors by Planck is certainly not a problem, a discovery in the medium to long term future is realistic.
PERSPECTIVES OF INFLATION TARGETING, IN THE CURRENT ECONOMIC CONTEXT
Directory of Open Access Journals (Sweden)
COROIU SORINA IOANA
2015-04-01
Full Text Available In the context of economic crisis, monetary policy makers are facing a number of challenges, including the selection and implementation of the best monetary policy. In this paper, we want to see if inflation targeting is or is not a solution to exit the economic crisis. If the answer is positive, then what would be the optimal level of inflation? Many central banks target an inflation rate of 2%. In this paper we intend to show that, in certain circumstances, a very low level of inflation can significantly reduce the stabilizing effects of monetary policy. A slightly higher value of inflation targeting would reduce the constraints on monetary policy, caused by the appearance of liquidity trap. The risk for the interest rates of monetary policy to achieve zero level is related to the central banks’ choise of the appropriate inflation target. We believe that an increase in the inflation target of 2% to 4% would ease monetary policy constraints arising from the liquidity trap problem. If inflation targeting is not a solution to exit the crisis, then are there other strategies that would be a better alternative? Following this analysis, no obvious alternatives were identified, so far, there is no clear reason for that to abandon inflation targeting.
Inflation protection from home-ownership : Long-run evidence
Brounen, Dirk; Eichholtz, P.; Staetmans, S.; Theebe, Marcel
2014-01-01
This article examines the inflation hedging capacity of the private home. We employ unique long-term data for inflation, house price dynamics and rents for Amsterdam dating back to 1814, allowing us to study total housing returns in different inflation regimes and for varying investment horizons.
46 CFR 185.518 - Inflatable survival craft placards.
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Inflatable survival craft placards. 185.518 Section 185... 100 GROSS TONS) OPERATIONS Preparations for Emergencies § 185.518 Inflatable survival craft placards. (a) Every vessel equipped with an inflatable survival craft must have approved placards or other...
Tourism Led-Inflation: A case of Malaysia
Directory of Open Access Journals (Sweden)
Shaari M. S.
2018-01-01
Full Text Available The importance of the tourism industry has prevailed among developed and even developing countries. It has been perceived to be an important contribution to economic growth. However, in the proliferation of studies on inflation, information on the extent to which tourism industry able to influence inflation, is still sparse. Therefore, this study embarks on investigating tourism as a potential factor towards inflation. Data on consumer price index and the number of tourist arrival from 1986 until 2014 are used in the analysis. This study adopts a quantitative approach employing the Autoregressive Distributed Lag (ARDL approach. Several controlled variables such as money supply, economic growth, government expenditure, and interest rate are also included. The results suggest that the tourism industry plays an important role in determining inflation in both short-and long-runs. Therefore, governments should take proactive measures in ascertaining that any expansion of the tourism industry can avert inflation.
Lin, Chia-Min; Cheung, Kingman
Following Ref. 10, we explore the parameter space of the case when the supersymmetry (SUSY) breaking scale is lower, for example, in gauge mediated SUSY breaking model. During inflation, the form of the potential is V0 plus MSSM (or A-term) inflation. We show that the model works for a wide range of the potential V0 with the soft SUSY breaking mass m O(1) TeV. The implication to MSSM (or A-term) inflation is that the flat directions which is lifted by the non-renormalizable terms described by the superpotential W=λ p φ p-1/Mp-3 P with p = 4 and p = 5 are also suitable to be an inflaton field for λp = O(1) provided there is an additional false vacuum term V0 with appropriate magnitude. The flat directions correspond to p = 6 also works for 0 < ˜ V0/M_ P4 < ˜ 10-40.
Inflation in random Gaussian landscapes
Energy Technology Data Exchange (ETDEWEB)
Masoumi, Ali; Vilenkin, Alexander; Yamada, Masaki, E-mail: ali@cosmos.phy.tufts.edu, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: Masaki.Yamada@tufts.edu [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)
2017-05-01
We develop analytic and numerical techniques for studying the statistics of slow-roll inflation in random Gaussian landscapes. As an illustration of these techniques, we analyze small-field inflation in a one-dimensional landscape. We calculate the probability distributions for the maximal number of e-folds and for the spectral index of density fluctuations n {sub s} and its running α {sub s} . These distributions have a universal form, insensitive to the correlation function of the Gaussian ensemble. We outline possible extensions of our methods to a large number of fields and to models of large-field inflation. These methods do not suffer from potential inconsistencies inherent in the Brownian motion technique, which has been used in most of the earlier treatments.
Individual differences in imagination inflation.
Heaps, C; Nash, M
1999-06-01
Garry, Manning, Loftus, and Sherman (1996) found that when adult subjects imagined childhood events, these events were subsequentlyjudged as more likely to have occurred than were not-imagined events. The authors termed this effect imagination inflation. We replicated the effect, using a novel set of Life Events Inventory events. Further, we tested whether the effect is related to four subject characteristics possibly associated with false memory creation. The extent to which subjects inflated judged likelihood following imagined events was associated with indices of hypnotic suggestibility and dissociativity, but not with vividness of imagery or interrogative suggestibility. Results suggest that imagination plays a role in subsequent likelihood judgments regarding childhood events, and that some individuals are more likely than others to experience imagination inflation.
Targeting nominal income growth or inflation?
DEFF Research Database (Denmark)
Jensen, Henrik
2002-01-01
Within a simple New Keynesian model emphasizing forward-looking behavior of private agents, I evaluate optimal nominal income growth targeting versus optimal inflation targeting. When the economy is mainly subject to shocks that do not involve monetary policy trade-offs for society, inflation...
78 FR 56868 - Adjustment of Indemnification for Inflation
2013-09-16
... DEPARTMENT OF ENERGY Adjustment of Indemnification for Inflation AGENCY: Office of General Counsel...-Anderson Act. Subsection 170t. of the AEA requires an inflation adjustment of the indemnification amount at... inflation-adjusted amount based on the aggregate percentage change in the CPI during the 5-year period from...
46 CFR 122.518 - Inflatable survival craft placards.
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Inflatable survival craft placards. 122.518 Section 122... Preparations for Emergencies § 122.518 Inflatable survival craft placards. (a) Every vessel equipped with an inflatable survival craft must have approved placards or other cards containing instructions for launching...
Inflation and dark energy from three-forms
International Nuclear Information System (INIS)
Koivisto, Tomi S.; Nunes, Nelson J.
2009-01-01
Three-forms can give rise to viable cosmological scenarios of inflation and dark energy with potentially observable signatures distinct from standard single scalar field models. In this study, the background dynamics and linear perturbations of self-interacting three-form cosmology are investigated. The phase space of cosmological solutions possesses (super)-inflating attractors and saddle points, which can describe three-form driven inflation or dark energy. The quantum generation and the classical evolution of perturbations is considered. The scalar and tensor spectra from a three-form inflation and the impact from the presence of a three-form on matter perturbations are computed. Stability properties and equivalence of the model with alternative formulations are discussed.
Issues on generating primordial anisotropies at the end of inflation
Energy Technology Data Exchange (ETDEWEB)
Emami, Razieh; Firouzjahi, Hassan, E-mail: emami@mail.ipm.ir, E-mail: firouz@mail.ipm.ir [School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)
2012-01-01
We revisit the idea of generating primordial anisotropies at the end of inflation in models of inflation with gauge fields. To be specific we consider the charged hybrid inflation model where the waterfall field is charged under a U(1) gauge field so the surface of end of inflation is controlled both by inflaton and the gauge fields. Using δN formalism properly we find that the anisotropies generated at the end of inflation from the gauge field fluctuations are exponentially suppressed on cosmological scales. This is because the gauge field evolves exponentially during inflation while in order to generate appreciable anisotropies at the end of inflation the spectator gauge field has to be frozen. We argue that this is a generic feature, that is, one can not generate observable anisotropies at the end of inflation within an FRW background.
Issues on generating primordial anisotropies at the end of inflation
International Nuclear Information System (INIS)
Emami, Razieh; Firouzjahi, Hassan
2012-01-01
We revisit the idea of generating primordial anisotropies at the end of inflation in models of inflation with gauge fields. To be specific we consider the charged hybrid inflation model where the waterfall field is charged under a U(1) gauge field so the surface of end of inflation is controlled both by inflaton and the gauge fields. Using δN formalism properly we find that the anisotropies generated at the end of inflation from the gauge field fluctuations are exponentially suppressed on cosmological scales. This is because the gauge field evolves exponentially during inflation while in order to generate appreciable anisotropies at the end of inflation the spectator gauge field has to be frozen. We argue that this is a generic feature, that is, one can not generate observable anisotropies at the end of inflation within an FRW background
On the bursting of linear polymer melts in inflation processes
DEFF Research Database (Denmark)
Rasmussen, Henrik Koblitz; Bach, Anders
2005-01-01
Molten LLDPE and HDPE plates (thickness 2 mm) have been inflated into a circular cylinder (inner radius 31 mm) under isothermal conditions. Low deformation rates allow the plates to be inflated considerably into the cylinder, and at high inflation rates an early burst is observed. Axis-symmetric ......Molten LLDPE and HDPE plates (thickness 2 mm) have been inflated into a circular cylinder (inner radius 31 mm) under isothermal conditions. Low deformation rates allow the plates to be inflated considerably into the cylinder, and at high inflation rates an early burst is observed. Axis...
Evaluation of Wavelet-based Core Inflation Measures: Evidence from Peru
Erick Lahura; Marco Vega
2011-01-01
Under inflation targeting and other related monetary policy regimes, the identication of non-transitory inflation and forecasts about future inflation constitute key ingredients for monetary policy decisions. In practice, central banks perform these tasks using so-called "core inflation measures". In this paper we construct alternative core inflation measures using wavelet functions and multiresolution analysis (MRA), and then evaluate their relevance for monetary policy. The construction of ...
International Nuclear Information System (INIS)
Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.A.; Srednicki, M.
1985-01-01
We present a simple model for primordial inflation in the context of SU(N, 1) no-scale n=1 supergravity. Because the model at zero temperature very closely resembles global supersymmetry, minima with negative cosmological constants do not exist, and it is easy to have a long inflationary epoch while keeping density perturbations of the right magnitude and satisfying other cosmological constraints. We pay specific attention to satisfying the thermal constraint for inflation, i.e. the existence of a high temperature minimum at the origin. (orig.)
Warm Inflation with Nonminimal Derivative Coupling
International Nuclear Information System (INIS)
Rashidi, N.; Nozari, Kourosh; Shoukrani, M.
2014-01-01
We study the effects of the nonminimal derivative coupling on the dissipative dynamics of the warm inflation where the scalar field is nonminimally coupled to gravity via its kinetic term. We present a detailed calculation of the cosmological perturbations in this setup. We use the recent observational data from the joint data set of WMAP9 + BAO + H 0 and also the Planck satellite data to constrain our model parameters for natural and chaotic inflation potentials. We study also the levels of non-Gaussianity in this warm inflation model and we confront the result with recent observational data from the Planck satellite
Heterogeneous inflation expectations, learning, and market outcomes
Madeira, Carlos; Zafar, Basit
2012-01-01
Using the panel component of the Michigan Survey of Consumers, we show that individuals, in particular women and ethnic minorities, are highly heterogeneous in their expectations of inflation. We estimate a model of inflation expectations based on learning from experience that also allows for heterogeneity in both private information and updating. Our model vastly outperforms existing models of inflation expectations in explaining the heterogeneity in the data. We find that women, ethnic mino...
Heterogeneus Inflation Expectations Learning and Market Outcomes
Carlos Madeira; Basit Zafar
2012-01-01
Using the panel component of the Michigan Survey of Consumers we estimate a learning model of inflation expectations, allowing for heterogeneous use of both private information and lifetime inflation experience. We find that women, ethnic minorities, and less educated agents have a higher degree of heterogeneity in their private information, and are slower to update their expectations. During the 2000s, consumers believe inflation to be more persistent in the short term, but temporary fluctua...
New type of hill-top inflation
Energy Technology Data Exchange (ETDEWEB)
Barvinsky, A.O.; Nesterov, D.V. [Theory Department, Lebedev Physics Institute, Leninsky Prospect 53, Moscow 119991 (Russian Federation); Kamenshchik, A.Yu., E-mail: barvin@td.lpi.ru, E-mail: Alexander.Kamenshchik@bo.infn.it, E-mail: nesterov@td.lpi.ru [Dipartimento di Fisica and INFN, via Irnerio 46, 40126 Bologna (Italy)
2016-01-01
We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model with a large number of quantum fields conformally coupled to gravity. Initial conditions for inflation are set up by cosmological instantons describing underbarrier oscillations in the vicinity of the inflaton potential maximum. These periodic oscillations of the inflaton field and cosmological scale factor are obtained within the approximation of two coupled oscillators subject to the slow roll regime in the Euclidean time. This regime is characterized by rapid oscillations of the scale factor on the background of a slowly varying inflaton, which guarantees smallness of slow roll parameters ε and η of the following inflation stage. A hill-like shape of the inflaton potential is shown to be generated by logarithmic loop corrections to the tree-level asymptotically shift-invariant potential in the non-minimal Higgs inflation model and R{sup 2}-gravity. The solution to the problem of hierarchy between the Planckian scale and the inflation scale is discussed within the concept of conformal higher spin fields, which also suggests the mechanism bringing the model below the gravitational cutoff and, thus, protecting it from large graviton loop corrections.
New type of hill-top inflation
Energy Technology Data Exchange (ETDEWEB)
Barvinsky, A.O. [Theory Department, Lebedev Physics Institute,Leninsky Prospect 53, Moscow 119991 (Russian Federation); Department of Physics, Tomsk State University,Lenin Ave. 36, Tomsk 634050 (Russian Federation); Department of Physics and Astronomy, Pacific Institue for Theoretical Physics,University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Kamenshchik, A.Yu. [Dipartimento di Fisica and INFN,via Irnerio 46, 40126 Bologna (Italy); L.D. Landau Institute for Theoretical Physcis,Kosygin str. 2, 119334 Moscow (Russian Federation); Nesterov, D.V. [Theory Department, Lebedev Physics Institute,Leninsky Prospect 53, Moscow 119991 (Russian Federation)
2016-01-20
We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model with a large number of quantum fields conformally coupled to gravity. Initial conditions for inflation are set up by cosmological instantons describing underbarrier oscillations in the vicinity of the inflaton potential maximum. These periodic oscillations of the inflaton field and cosmological scale factor are obtained within the approximation of two coupled oscillators subject to the slow roll regime in the Euclidean time. This regime is characterized by rapid oscillations of the scale factor on the background of a slowly varying inflaton, which guarantees smallness of slow roll parameters ϵ and η of the following inflation stage. A hill-like shape of the inflaton potential is shown to be generated by logarithmic loop corrections to the tree-level asymptotically shift-invariant potential in the non-minimal Higgs inflation model and R{sup 2}-gravity. The solution to the problem of hierarchy between the Planckian scale and the inflation scale is discussed within the concept of conformal higher spin fields, which also suggests the mechanism bringing the model below the gravitational cutoff and, thus, protecting it from large graviton loop corrections.
Evolution of the curvature perturbations during warm inflation
International Nuclear Information System (INIS)
Matsuda, Tomohiro
2009-01-01
This paper considers warm inflation as an interesting application of multi-field inflation. Delta-N formalism is used for the calculation of the evolution of the curvature perturbations during warm inflation. Although the perturbations considered in this paper are decaying after the horizon exit, the corrections to the curvature perturbations sourced by these perturbations can remain and dominate the curvature perturbations at large scales. In addition to the typical evolution of the curvature perturbations, inhomogeneous diffusion rate is considered for warm inflation, which may lead to significant non-Gaussianity of the spectrum
Creating perturbations from a decaying field during inflation
DEFF Research Database (Denmark)
Mazumdar, A.; Wang, L.
2013-01-01
Typically, the fluctuations generated from a decaying field during inflation do not contribute to the large scale structures. In this paper, we provide an example where it is possible for a field which slowly rolls and then decays during inflation to create all the matter perturbations with a sli......Typically, the fluctuations generated from a decaying field during inflation do not contribute to the large scale structures. In this paper, we provide an example where it is possible for a field which slowly rolls and then decays during inflation to create all the matter perturbations...
Quarterly inflation rate target and forecasts in Romania
Directory of Open Access Journals (Sweden)
Mihaela Simionescu
2016-12-01
Full Text Available In this study, we proposed some inflation rate predictions based on econometric models that performed better than the targets of the National Bank of Romania. Few econometric models (multiple regressions model and a vector-autoregression were used to predict the quarterly inflation rate in Romania during 2000:Q1-2016:Q4. The GDP growth has a negative impact on inflation rate in Romania, an increase in logarithm of GDP with one percentage point determining a decrease in inflation logarithm with less than 0.1 units according to both proposed models. However, an increase in inflation rate in the previous period determined an increase in this variable in the current period. The inverse of unemployment rate is positively correlated with the index of prices. The causal relationship between inflation rate and unemployment rate is reciprocal. In the first period the index of prices evolution is explained only by changes in this variable. The inflation rate volatility is due mainly to the evolution of this indicator, the influence decreasing insignificantly in time, not descending under 88%. More than 99% of the variation in unemployment rate is explained by the own volatility for all lags. The annual forecasts based on these models performed better than the targets on the horizon 2015-2016.
77 FR 65100 - Adjustment of Civil Monetary Penalties for Inflation
2012-10-25
... Penalties for Inflation AGENCY: Commodity Futures Trading Commission ACTION: Final rule. SUMMARY: The... civil monetary penalties, to adjust for inflation. This rule sets forth the maximum, inflation-adjusted... Federal Civil Penalties Inflation Adjustment Act of 1990, as amended by the Debt Collection Improvement...
10 CFR 765.12 - Inflation index adjustment procedures.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Inflation index adjustment procedures. 765.12 Section 765... THORIUM PROCESSING SITES Reimbursement Criteria § 765.12 Inflation index adjustment procedures. (a) The... § 765.2(i) of this rule) shall be adjusted for inflation as provided by this section. (b) To make...
Enqvist, K
2012-01-01
The very basics of cosmological inflation are discussed. We derive the equations of motion for the inflaton field, introduce the slow-roll parameters, and present the computation of the inflationary perturbations and their connection to the temperature fluctuations of the cosmic microwave background.
Felder, G; Linde, Andrei D; Tkachev, Igor I; Felder, Gary; Kofman, Lev; Linde, Andrei; Tkachev, Igor
2000-01-01
Preheating after inflation may lead to nonthermal phase transitions with symmetry restoration. These phase transitions may occur even if the total energy density of fluctuations produced during reheating is relatively small as compared with the vacuum energy in the state with restored symmetry. As a result, in some inflationary models one encounters a secondary, nonthermal stage of inflation due to symmetry restoration after preheating. We review the theory of nonthermal phase transitions and make a prediction about the expansion factor during the secondary inflationary stage. We then present the results of lattice simulations which verify these predictions, and discuss possible implications of our results for the theory of formation of topological defects during nonthermal phase transitions.
Inflation perceptions and inflation expectation in South Africa: trends ...
African Journals Online (AJOL)
Inflation expectations are related to expected future changes .... had to choose from a menu of options with a further response in one instance, while .... 1The marginal effect or partial derivatives depend on the value of x, and the marginal.
Zero inflated negative binomial-Sushila distribution and its application
Yamrubboon, Darika; Thongteeraparp, Ampai; Bodhisuwan, Winai; Jampachaisri, Katechan
2017-11-01
A new zero inflated distribution is proposed in this work, namely the zero inflated negative binomial-Sushila distribution. The new distribution which is a mixture of the Bernoulli and negative binomial-Sushila distributions is an alternative distribution for the excessive zero counts and over-dispersion. Some characteristics of the proposed distribution are derived including probability mass function, mean and variance. The parameter estimation of the zero inflated negative binomial-Sushila distribution is also implemented by maximum likelihood method. In application, the proposed distribution can provide a better fit than traditional distributions: zero inflated Poisson and zero inflated negative binomial distributions.
Inflation risk and international asset returns
G.A. Moerman (Gerard); M.A. van Dijk (Mathijs)
2010-01-01
textabstractWe show that inflation risk is priced in international asset returns. We analyze inflation risk in a framework that encompasses the International Capital Asset Pricing Model (ICAPM) of Adler and Dumas (1983). In contrast to the extant empirical literature on the ICAPM, we relax the
No-scale D-term inflation with stabilized moduli
Energy Technology Data Exchange (ETDEWEB)
Buchmueller, Wilfried; Domcke, Valerie; Wieck, Clemens
2013-09-15
We study the consistency of hybrid inflation and moduli stabilization, using the Kallosh- Linde model as an example for the latter. We find that F-term hybrid inflation is not viable since inflationary trajectories are destabilized by tachyonic modes. On the other hand, D-term hybrid inflation is naturally compatible with moduli stabilization due to the absence of a large superpotential term during the inflationary phase. Our model turns out to be equivalent to superconformal D-term inflation and it therefore successfully accounts for the CMB data in the large-field regime. Supersymmetry breaking can be incorporated via an O'Raifeartaigh model. For GUT-scale inflation one obtains a stringent bound on the gravitino mass. A rough estimate yields m{sub 3/2}>or similar 10{sup 5} GeV, contrary to naive expectation.
No-scale D-term inflation with stabilized moduli
International Nuclear Information System (INIS)
Buchmueller, Wilfried; Domcke, Valerie; Wieck, Clemens
2013-09-01
We study the consistency of hybrid inflation and moduli stabilization, using the Kallosh- Linde model as an example for the latter. We find that F-term hybrid inflation is not viable since inflationary trajectories are destabilized by tachyonic modes. On the other hand, D-term hybrid inflation is naturally compatible with moduli stabilization due to the absence of a large superpotential term during the inflationary phase. Our model turns out to be equivalent to superconformal D-term inflation and it therefore successfully accounts for the CMB data in the large-field regime. Supersymmetry breaking can be incorporated via an O'Raifeartaigh model. For GUT-scale inflation one obtains a stringent bound on the gravitino mass. A rough estimate yields m 3/2 >or similar 10 5 GeV, contrary to naive expectation.
Inflation and the theory of cosmological perturbations
International Nuclear Information System (INIS)
Riotto, A.
2003-01-01
These lectures provide a pedagogical introduction to inflation and the theory of cosmological perturbations generated during inflation which are thought to be the origin of structure in the universe. (author)
Solving stochastic inflation for arbitrary potentials
International Nuclear Information System (INIS)
Martin, Jerome; Musso, Marcello
2006-01-01
A perturbative method for solving the Langevin equation of inflationary cosmology in the presence of backreaction is presented. In the Gaussian approximation, the method permits an explicit calculation of the probability distribution of the inflaton field for an arbitrary potential, with or without the volume effects taken into account. The perturbative method is then applied to various concrete models, namely, large field, small field, hybrid, and running mass inflation. New results on the stochastic behavior of the inflaton field in those models are obtained. In particular, it is confirmed that the stochastic effects can be important in new inflation while it is demonstrated they are negligible in (vacuum dominated) hybrid inflation. The case of stochastic running mass inflation is discussed in some details and it is argued that quantum effects blur the distinction between the four classical versions of this model. It is also shown that the self-reproducing regime is likely to be important in this case
Private Sector Credit and Inflation Volatility
Directory of Open Access Journals (Sweden)
Lorna Katusiime
2018-04-01
Full Text Available This paper investigates the effect of inflation volatility on private sector credit growth. The results indicate that private sector credit growth is positively linked to the one period lagged inflation volatility. Given that past monetary policy actions continue to affect the targeted variables due to the substantial lags in the transmission mechanism, the positive response of private sector credit growth to past inflation volatility suggests a credible monetary policy regime in Uganda, which has led to a reduction in the level of macroeconomic uncertainty and the restoration of favorable economic conditions and prospects, thus increasing the demand for credit. Further, the study finds that the lagged private sector credit growth, nominal exchange rate, and inflation have a statistically significant effect on private sector credit growth while financial innovation, interest rates, and GDP growth appear not to be important determinants of private sector credit growth. The robustness of our findings is confirmed by sensitivity checks.
Simple types of anisotropic inflation
International Nuclear Information System (INIS)
Barrow, John D.; Hervik, Sigbjoern
2010-01-01
We display some simple cosmological solutions of gravity theories with quadratic Ricci curvature terms added to the Einstein-Hilbert Lagrangian which exhibit anisotropic inflation. The Hubble expansion rates are constant and unequal in three orthogonal directions. We describe the evolution of the simplest of these homogeneous and anisotropic cosmological models from its natural initial state and evaluate the deviations they will create from statistical isotropy in the fluctuations produced during a period of anisotropic inflation. The anisotropic inflation is not a late-time attractor in these models but the rate of approach to a final isotropic de Sitter state is slow and is conducive to the creation of observable anisotropic statistical effects in the microwave background. The statistical anisotropy would not be scale invariant and the level of statistical anisotropy will grow with scale.
A note on calm excited states of inflation
International Nuclear Information System (INIS)
Ashoorioon, Amjad; Shiu, Gary
2011-01-01
We identify a two-parameter family of excited states within slow-roll inflation for which either the corrections to the two-point function or the characteristic signatures of excited states in the three-point function — i.e. the enhancement for the flattened momenta configurations– are absent. These excited states may nonetheless violate the adiabaticity condition maximally. We dub these initial states of inflation calm excited states. We show that these two sets do not intersect, i.e., those that leave the power-spectrum invariant can be distinguished from their bispectra, and vice versa. The same set of calm excited states that leave the two-point function invariant for slow-roll inflation, do the same task for DBI inflation. However, at the level of three-point function, the calm excited states whose flattened configuration signature is absent for slow-roll inflation, will lead to an enhancement for DBI inflation generally, although the signature is smaller than what suggested by earlier analysis. This example also illustrates that imposing the Wronskian condition is important for obtaining a correct estimate of the non-Gaussian signatures
A state-dependent model for inflation forecasting
Andrea Stella; James H. Stock
2012-01-01
We develop a parsimonious bivariate model of inflation and unemployment that allows for persistent variation in trend inflation and the NAIRU. The model, which consists of five unobserved components (including the trends) with stochastic volatility, implies a time-varying VAR for changes in the rates of inflation and unemployment. The implied backwards-looking Phillips curve has a time-varying slope that is steeper in the 1970s than in the 1990s. Pseudo out-of-sample forecasting experiments i...
Inflation targeting and interest rate policy
Verhagen, W.H.
2001-01-01
The thesis contains a collection of papers on issues in inflation targeting and its implications for the way interest rates are set. In this respect, the first part deals with two largely positive issues: the effect of inflation forecast targeting on the term structure of interest rates and the
Inflation with a constant rate of roll
International Nuclear Information System (INIS)
Motohashi, Hayato; Starobinsky, Alexei A.; Yokoyama, Jun'ichi
2015-01-01
We consider an inflationary scenario where the rate of inflaton roll defined by ·· φ/H φ-dot remains constant. The rate of roll is small for slow-roll inflation, while a generic rate of roll leads to the interesting case of 'constant-roll' inflation. We find a general exact solution for the inflaton potential required for such inflaton behaviour. In this model, due to non-slow evolution of background, the would-be decaying mode of linear scalar (curvature) perturbations may not be neglected. It can even grow for some values of the model parameter, while the other mode always remains constant. However, this always occurs for unstable solutions which are not attractors for the given potential. The most interesting particular cases of constant-roll inflation remaining viable with the most recent observational data are quadratic hilltop inflation (with cutoff) and natural inflation (with an additional negative cosmological constant). In these cases even-order slow-roll parameters approach non-negligible constants while the odd ones are asymptotically vanishing in the quasi-de Sitter regime
Inflation, economic policy, and the inner city
Energy Technology Data Exchange (ETDEWEB)
Curtis, L.A.
1981-07-01
This article describes the greater impact of inflation among the poor and minorities in American inner cities than among other population groups. Surveys show, however, that minorities are even more concerned over unemployment and racial discrimination than over inflation. There are indications that, especially today, crime and potential group disorder are affected by or influence inflation, unemployment, and discrimination in the inner city. With these interrelated factors in mind, present federal economic policy is reviewed, critiqued, and interpreted as basically consistent with Keynesian economic theory. Modifications of and alternatives to present policy are offered that fit both inner-city needs and the concerns of the rest of American society. These policies include targeted private sector neighborhood development and self-help, private sector productivity increases through workplace democracy, private-public sector codetermination of investment, private-public sector job guarantees, and public anti-inflation policy carefully targeted at the basic necessities of energy, food, housing, and health care - which have a disproportionate effect on inflation in the inner city, as well as the overall economy. Coalitions are suggested that could politically implement such policies.
Origin of density fluctuations in extended inflation
International Nuclear Information System (INIS)
Kolb, E.W.; Salopek, D.S.; Turner, M.S.
1990-05-01
The density fluctuations (both curvature and isocurvature) that arise due to quantum fluctuations in a simple model of extended inflation based upon the Jordan-Brans-Dicke theory are calculated. Curvature fluctuations arise due to quantum fluctuations in the Brans-Dicke field, in general have a nonscale-invariant spectrum, and can have an amplitude that is cosmologically acceptable and interesting without having to tune any coupling constant to a very small value. The density perturbations that arise due to the inflation field are subdominant. If there are other massless fields in the theory, e.g., an axion or an ilion, then isocurvature fluctuations arise in these fields too. Production of gravitational waves and the massless particles associated with excitations of the Brans-Dicke field are also discussed. Several attempts at more realistic models of extended inflation are also analyzed. The importance of the Einstein conformal frame in calculating curvature fluctuations is emphasized. When viewed in this frame, extended inflation closely resembles slow-rollover inflation with an exponential potential and the usual formula for the amplitude of curvature perturbations applies
Curvaton as dark matter with secondary inflation
Energy Technology Data Exchange (ETDEWEB)
Gong, Jinn-Ouk; Kitajima, Naoya [Asia Pacific Center for Theoretical Physics, Pohang 37673 (Korea, Republic of); Terada, Takahiro, E-mail: jinn-ouk.gong@apctp.org, E-mail: naoya.kitajima@apctp.org, E-mail: terada@kias.re.kr [Korea Institute for Advanced Study, Seoul 02455 (Korea, Republic of)
2017-03-01
We consider a novel cosmological scenario in which a curvaton is long-lived and plays the role of cold dark matter (CDM) in the presence of a short, secondary inflation. Non-trivial evolution of the large scale cosmological perturbation in the curvaton scenario can affect the duration of the short term inflation, resulting in the inhomogeneous end of inflation. Non-linear parameters of the curvature perturbation are predicted to be f {sub NL} ≈ 5/4 and g {sub NL} ≈ 0. The curvaton abundance can be well diluted by the short-term inflation and accordingly, it does not have to decay into the Standard Model particles. Then the curvaton can account for the present CDM with the isocurvature perturbation being sufficiently suppressed because both the adiabatic and CDM isocurvature perturbations have the same origin. As an explicit example, we consider the thermal inflation scenario and a string axion as a candidate for this curvaton-dark matter. We further discuss possibilities to identify the curvaton-dark matter with the QCD axion.
Wirelessly Controllable Inflated Electroactive Polymer (EAP) Reflectors
Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart; Badescu, Mircea
2005-01-01
Inflatable membrane reflectors are attractive for deployable, large aperture, lightweight optical and microwave systems in micro-gravity space environment. However, any fabrication flaw or temperature variation may results in significant aberration of the surface. Even for a perfectly fabricated inflatable membrane mirror with uniform thickness, theory shows it will form a Hencky curve surface but a desired parabolic or spherical surface. Precision control of the surfaceshape of extremely flexible membrane structures is a critical challenge for the success of this technology. Wirelessly controllable inflated reflectors made of electroactive polymers (EAP) are proposed in this paper. A finite element model was configured to predict the behavior of the inflatable EAP membranes under pre-strains, pressures and distributed electric charges on the surface. To explore the controllability of the inflatable EAP reflectors, an iteration algorism was developed to find the required electric actuation for correcting the aberration of the Hencky curve to the desired parabolic curve. The correction capability of the reflectors with available EAP materials was explored numerically and is presented in this paper.
What Is Wrong with Grade Inflation (If Anything)?
Finefter-Rosenbluh, Ilana; Levinson, Meira
2015-01-01
Grade inflation is a global phenomenon that has garnered widespread condemnation among educators, researchers, and the public. Yet, few have deliberated over the ethics of grading, let alone the ethics of grade inflation. The purpose of this paper is to map out and examine the ethics of grade inflation. By way of beginning, we clarify why grade…
Air Tight: Building Inflatables/Inflatable Construction: Planning and Details
Kennedy, Kriss J.
2016-01-01
A design-build seminar consisting of students from Physics, Mechanical and Civil Engineering, Robotic, Material Science, Art, and Architecture who will work together on a deployable "closed-loop" inflatable greenhouse for Mars in theory, and an Earth analogue physical mockup on campus.
A picture for the coupling of unemployment and inflation
Safdari, H.; Hosseiny, A.; Vasheghani Farahani, S.; Jafari, G. R.
2016-02-01
The aim of this article is to illustrate the scaling features of two well heard characters in the media; unemployment and inflation. We carry out a scaling analysis on the coupling between unemployment and inflation. This work is based on the wavelet analysis as well as the detrended fluctuation analysis (DFA). Through our analysis we state that while unemployment is time scale invariant, inflation is bi-scale. We show that inflation possess a five year time scale where it experiences different behaviours before and after this scale period. This behaviour of inflation provides basis for the coupling to inherit the stated time interval. Although inflation is bi-scale, it is unemployment that shows a strong multifractality feature. Owing to the cross wavelet analysis we provide a picture that illustrates the dynamics of coupling between unemployment and inflation regarding intensity, direction, and scale. The fact of the matter is that the coupling between inflation and unemployment is not equal in one way compared to the opposite. Regarding the scaling; coupling exhibits different features in various scales. In a sense that although in one scale its correlation behaves in a positive/negative manner, at the same time it can be negative/positive for another scale.
Dark energy from gravitoelectromagnetic inflation?
Membiela, F. A.; Bellini, M.
2008-02-01
Gravitoectromagnetic Inflation (GI) was introduced to describe in an unified manner, electromagnetic, gravitatory and inflaton fields from a 5D vacuum state. On the other hand, the primordial origin and evolution of dark energy is today unknown. In this letter we show using GI that the zero modes of some redefined vector fields $B_i=A_i/a$ produced during inflation, could be the source of dark energy in the universe.
Inflation, Reionization, and All That: The Primordial Inflation Explorer
Kogut, Alan J.
2012-01-01
The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10(exp -3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.
Combining high-scale inflation with low-energy SUSY
Energy Technology Data Exchange (ETDEWEB)
Antusch, Stefan [Basel Univ. (Switzerland). Dept. of Physics; Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut; Dutta, Koushik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Halter, Sebastian [Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut
2011-12-15
We propose a general scenario for moduli stabilization where low-energy supersymmetry can be accommodated with a high scale of inflation. The key ingredient is that the stabilization of the modulus field during and after inflation is not associated with a single, common scale, but relies on two different mechanisms. We illustrate this general scenario in a simple example, where during inflation the modulus is stabilized with a large mass by a Kaehler potential coupling to the field which provides the inflationary vacuum energy via its F-term. After inflation, the modulus is stabilized, for instance, by a KKLT superpotential. (orig.)
Heterogeneity, learning and information stickiness in inflation expectations
DEFF Research Database (Denmark)
Pfajfar, Damjan; Santoro, Emiliano
2010-01-01
In this paper we propose novel techniques for the empirical analysis of adaptive learning and sticky information in inflation expectations. These methodologies are applied to the distribution of households’ inflation expectations collected by the University of Michigan Survey Research Center....... To account for the evolution of the cross-section of inflation forecasts over time and measure the degree of heterogeneity in private agents’ forecasts, we explore time series of percentiles from the empirical distribution. Our results show that heterogeneity is pervasive in the process of inflation...... hand side of the median formed in accordance with adaptive learning and sticky information....
Evading Lyth bound in models of quintessential inflation
International Nuclear Information System (INIS)
Hossain, Md. Wali; Myrzakulov, R.; Sami, M.; Saridakis, Emmanuel N.
2014-01-01
Quintessential inflation refers to an attempt to unify inflation and late-time cosmic acceleration using a single scalar field. In this letter we consider two different classes of quintessential inflation, one of which is based upon a Lagrangian with non-canonical kinetic term k 2 (ϕ)∂ μ ϕ∂ μ ϕ and a steep exponential potential while the second class uses the concept of steep brane world inflation. We show that in both cases the Lyth bound can be evaded, despite the large tensor-to-scalar ratio of perturbations. The post-inflationary dynamics is consistent with nucleosynthesis constraint in these cases
MHz gravitational waves from short-term anisotropic inflation
International Nuclear Information System (INIS)
Ito, Asuka; Soda, Jiro
2016-01-01
We reveal the universality of short-term anisotropic inflation. As a demonstration, we study inflation with an exponential type gauge kinetic function which is ubiquitous in models obtained by dimensional reduction from higher dimensional fundamental theory. It turns out that an anisotropic inflation universally takes place in the later stage of conventional inflation. Remarkably, we find that primordial gravitational waves with a peak amplitude around 10 −26 ∼10 −27 are copiously produced in high-frequency bands 10 MHz∼100 MHz. If we could detect such gravitational waves in future, we would be able to probe higher dimensional fundamental theory.
Replenishment policy for an inventory model under inflation
Singh, Vikramjeet; Saxena, Seema; Singh, Pushpinder; Mishra, Nitin Kumar
2017-07-01
The purpose of replenishment is to keep the flow of inventory in the system. To determine an optimal replenishment policy is a great challenge in developing an inventory model. Inflation is defined as the rate at which the prices of goods and services are rising over a time period. The cost parameters are affected by the rate of inflation. High rate of inflation affects the organizations financial conditions. Based on the above backdrop the present paper proposes the retailers replenishment policy for deteriorating items with different cycle lengths under inflation. The shortages are partially backlogged. At last numerical examples validate the results.
Portfolio Management with Stochastic Interest Rates and Inflation Ambiguity
DEFF Research Database (Denmark)
Munk, Claus; Rubtsov, Alexey Vladimirovich
We solve a stock-bond-cash portfolio choice problem for a risk- and ambiguity-averse investor in a setting where the inflation rate and interest rates are stochastic. The expected inflation rate is unobservable, but the investor may learn about it from realized inflation and observed stock and bond...... prices. The investor is aware that his model for the observed inflation is potentially misspecified, and he seeks an investment strategy that maximizes his expected utility from real terminal wealth and is also robust to inflation model misspecification. We solve the corresponding robust Hamilton......-Jacobi-Bellman equation in closed form and derive and illustrate a number of interesting properties of the solution. For example, ambiguity aversion affects the optimal portfolio through the correlation of price level with the stock index, a bond, and the expected inflation rate. Furthermore, unlike other settings...
Spontaneous non-thermal leptogenesis in high-scale inflation models
International Nuclear Information System (INIS)
Endo, M.; Takahashi, F.; Yanagida, T.T.; Tokyo Univ.
2006-11-01
We argue that a non-thermal leptogenesis occurs spontaneously, without direct couplings of the inflation with right-handed neutrinos, in a wide class of high-scale inflation models such as the chaotic and hybrid inflation. It is only a finite vacuum expectation value of the inflaton, of more precisely, a linear term in the Kaehler potential, that is a prerequisite for the spontaneous non-thermal leptogenesis. To exemplify how it works, we show that a chaotic inflation model in supergravity naturally produces a right amount of baryon asymmetry via the spontaneous non-thermal leptogenesis. We also discuss the gravitino production from the inflation. (orig.)
Inflation in the Universe, circa 1986
International Nuclear Information System (INIS)
Turner, M.S.; Chicago Univ., IL
1988-01-01
The status of the 'Inflationary Paradigm', Circa 1986 is reviewed. At present essentially all inflationary models involve a very weakly-coupled scalar field which is displaced from the minimum of its potential. Regions of the Universe where the scalar field is initially displaced from its minimum undergo inflation as the scalar field relaxes, resulting in a Universe today which resembles ours in regions much larger than our present Hubble volume (≅ 10 28 cm), but which on very largescales (>> 10 28 cm) may be highly irregular. Some other unresolved issues facing inflation, including the confrontation between the predictions of inflation and observational data, are also reviewed. (author) 113 refs.; 4 figs
First observational tests of eternal inflation.
Feeney, Stephen M; Johnson, Matthew C; Mortlock, Daniel J; Peiris, Hiranya V
2011-08-12
The eternal inflation scenario predicts that our observable Universe resides inside a single bubble embedded in a vast inflating multiverse. We present the first observational tests of eternal inflation, performing a search for cosmological signatures of collisions with other bubble universes in cosmic microwave background data from the WMAP satellite. We conclude that the WMAP 7-year data do not warrant augmenting the cold dark matter model with a cosmological constant with bubble collisions, constraining the average number of detectable bubble collisions on the full sky N(s) < 1.6 at 68% C.L. Data from the Planck satellite can be used to more definitively test the bubble-collision hypothesis.
On inflating magnetic fields, and the backreactions thereof
Energy Technology Data Exchange (ETDEWEB)
Urban, Federico R., E-mail: urban@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1 (Canada)
2011-12-01
We investigate in more depth the issue of backreaction in models that attempt at generating cosmological magnetic fields at inflation. By choosing different, physically motivated, parametrisations, we are able to isolate the heart of the problem, namely the existence, alongside the wanted magnetic field, of its electric counterpart, which turns out quite generally to be stronger and redder. We were also able to identify a few more interwoven weak spots (the typically very high scale of inflation, the width of the spectrum of modes processed by inflation, the blindness of the amplification mechanism to the energy scale processed), in a way independent on the specifications of the coupling between inflation and electromagnetism. Despite having stripped down the problem to the core, the obstacles encountered appear insurmountable, thereby posing a challenge to inflation as the incubator of cosmological magnetism.
Natural inflation and moduli stabilization in heterotic orbifolds
International Nuclear Information System (INIS)
Ruehle, Fabian; Wieck, Clemens
2015-03-01
We study moduli stabilization in combination with inflation in heterotic orbifold compactifications in the light of a large Hubble scale and the favored tensor-to-scalar ratio r∼0.05. To account for a trans-Planckian field range we implement aligned natural inflation. Although there is only one universal axion in heterotic constructions, further axions from the geometric moduli can be used for alignment and inflation. We argue that such an alignment is rather generic on orbifolds, since all non-perturbative terms are determined by modular weights of the involved fields and the Dedekind η function. We present two setups inspired by the mini-landscape models of the Z 6-II orbifold which realize aligned inflation and stabilization of the relevant moduli. One has a supersymmetric vacuum after inflation, while the other includes a gaugino condensate which breaks supersymmetry at a high scale.
End of multifield inflation and the perturbation spectrum
International Nuclear Information System (INIS)
Gong, Jinn-Ouk
2007-01-01
We investigate the dynamics of inflation models driven by multiple, decoupled scalar fields and calculate the Hubble parameter and the amplitude of the lightest field at the end of inflation which may be responsible for interesting, or possibly dangerous cosmological consequences after inflation. The results are very simple and similar to those of the single field inflation, mainly depending on the underlying spectrum of the masses. The mass distribution is heavily constrained by the power spectrum of density perturbations P and the spectral index n s . The overall mass scale gives the amplitude of P, and n s is affected by the number of fields and the spacing between masses in the distribution. The dropout effect of the massive fields makes the perturbation spectrum typically redder than the single field inflation spectrum. We illustrate this using two different mass distributions
Inflation Targeting and Exchange Rate Management in Korea
Directory of Open Access Journals (Sweden)
Won-Am Park
2008-06-01
Full Text Available This paper investigates the experience of inflation targeting in Korea with an emphasis on exchange rate management. The Korean call rate responded to not only expected inflation, but also to output gap and changes in the real effective exchange rate of the Korean won, when we estimated the call rate reaction function over the period of 1999-2007. It was found that the call rate responded to changes in real effective exchange rate more than it did to expected inflation. We also examined whether Korean inflation targeting was actually centered on the exchange rate by estimating the Singaporean style of exchange rate reaction function. It was found that Korean monetary policy was not exchange-rate- centered, since the nominal effective exchange rate of the Korean won responded modestly to inflation and output gap, far less than did the Singaporean dollar.
Rapid roll inflation with conformal coupling
International Nuclear Information System (INIS)
Kofman, Lev; Mukohyama, Shinji
2008-01-01
Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor inflationary solution with the rapidly rolling inflaton field. We discuss models with the conformal inflaton with a flat potential (including hybrid inflation). There is no generation of cosmological fluctuations from the conformally coupled inflaton. We consider realizations of modulated (inhomogeneous reheating) or curvaton cosmological fluctuations in these models. We also implement these unusual features for the popular string-theoretic warped inflationary scenario, based on the interacting D3-D3 branes. The original warped brane inflation suffers a large inflaton mass due to conformal coupling to 4-dimensional gravity. Instead of considering this as a problem and trying to cure it with extra engineering, we show that warped inflation with the conformally coupled, rapidly rolling inflaton is yet possible with N=37 efoldings, which requires low-energy scales 1-100 TeV of inflation. Coincidentally, the same warping numerology can be responsible for the hierarchy. It is shown that the scalars associated with angular isometries of the warped geometry of compact manifold (e.g. S 3 of Klebanov-Strassler (KS) geometry) have solutions identical to conformally coupled modes and also cannot be responsible for cosmological fluctuations. We discuss other possibilities
Rapid roll inflation with conformal coupling
Kofman, Lev; Mukohyama, Shinji
2008-02-01
Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor inflationary solution with the rapidly rolling inflaton field. We discuss models with the conformal inflaton with a flat potential (including hybrid inflation). There is no generation of cosmological fluctuations from the conformally coupled inflaton. We consider realizations of modulated (inhomogeneous reheating) or curvaton cosmological fluctuations in these models. We also implement these unusual features for the popular string-theoretic warped inflationary scenario, based on the interacting D3-D¯3 branes. The original warped brane inflation suffers a large inflaton mass due to conformal coupling to 4-dimensional gravity. Instead of considering this as a problem and trying to cure it with extra engineering, we show that warped inflation with the conformally coupled, rapidly rolling inflaton is yet possible with N=37 efoldings, which requires low-energy scales 1 100 TeV of inflation. Coincidentally, the same warping numerology can be responsible for the hierarchy. It is shown that the scalars associated with angular isometries of the warped geometry of compact manifold (e.g. S3 of Klebanov-Strassler (KS) geometry) have solutions identical to conformally coupled modes and also cannot be responsible for cosmological fluctuations. We discuss other possibilities.
Herrera, Ramón
2017-05-01
A warm inflationary universe in the context of Galileon model or G-model is studied. Under a general formalism we study the inflationary dynamics and the cosmological perturbations considering a coupling of the form G(phi,X)=g(phi) X. As a concrete example, we consider an exponential potential together with the cases in which the dissipation and Galilean coefficients are constants. Also, we study the weak regime given by the condition RR+3gHdot phi. Additionally, we obtain constraints on the parameters during the evolution of G-warm inflation, assuming the condition for warm inflation in which the temperature T>H, the conditions or the weak and strong regimes, together with the consistency relation r=r(ns) from Planck data.
Energy Technology Data Exchange (ETDEWEB)
Bachlechner, Thomas C. [Department of Physics, Columbia University,New York, NY 10027 (United States)
2016-12-30
We argue that moduli stabilization generically restricts the evolution following transitions between weakly coupled de Sitter vacua and can induce a strong selection bias towards inflationary cosmologies. The energy density of domain walls between vacua typically destabilizes Kähler moduli and triggers a runaway towards large volume. This decompactification phase can collapse the new de Sitter region unless a minimum amount of inflation occurs after the transition. A stable vacuum transition is guaranteed only if the inflationary expansion generates overlapping past light cones for all observable modes originating from the reheating surface, which leads to an approximately flat and isotropic universe. High scale inflation is vastly favored. Our results point towards a framework for studying parameter fine-tuning and inflationary initial conditions in flux compactifications.
Chameleon field dynamics during inflation
Saba, Nasim; Farhoudi, Mehrdad
By studying the chameleon model during inflation, we investigate whether it can be a successful inflationary model, wherein we employ the common typical potential usually used in the literature. Thus, in the context of the slow-roll approximations, we obtain the e-folding number for the model to verify the ability of resolving the problems of standard big bang cosmology. Meanwhile, we apply the constraints on the form of the chosen potential and also on the equation of state parameter coupled to the scalar field. However, the results of the present analysis show that there is not much chance of having the chameleonic inflation. Hence, we suggest that if through some mechanism the chameleon model can be reduced to the standard inflationary model, then it may cover the whole era of the universe from the inflation up to the late time.
Partially massless fields during inflation
Baumann, Daniel; Goon, Garrett; Lee, Hayden; Pimentel, Guilherme L.
2018-04-01
The representation theory of de Sitter space allows for a category of partially massless particles which have no flat space analog, but could have existed during inflation. We study the couplings of these exotic particles to inflationary perturbations and determine the resulting signatures in cosmological correlators. When inflationary perturbations interact through the exchange of these fields, their correlation functions inherit scalings that cannot be mimicked by extra massive fields. We discuss in detail the squeezed limit of the tensor-scalar-scalar bispectrum, and show that certain partially massless fields can violate the tensor consistency relation of single-field inflation. We also consider the collapsed limit of the scalar trispectrum, and find that the exchange of partially massless fields enhances its magnitude, while giving no contribution to the scalar bispectrum. These characteristic signatures provide clean detection channels for partially massless fields during inflation.
INFLATION TARGETING IN EASTERN EUROPE
Directory of Open Access Journals (Sweden)
Laurian Lungu
2006-05-01
Full Text Available This paper addresses the inflation targeting approach in three transition economies, namely Hungary, Poland and the Czech Republic with the use of Taylor rules as benchmarks. The three economies considered have been successful at achieving disinflation, but deviations of inflation from its target have been persistent in all cases. Except for the Czech Republic, deviations from the Taylor rule are large and persistent, with Hungary displaying the largest fluctuations. Polish interest rates have consistently exceeded those suggested by the Taylor rule and given the prevalence of high unemployment, these undershootings do not augur well for the stability of monetary policy. Finally, the behaviour of Czech interest rates can be remarkably captured by the simple Taylor rule proposed in this paper, suggesting that the Czech National Bank has been the most successful at stabilising inflation and output around their target levels.
Inflation and cosmic strings: Two mechanisms for producing structure in the universe
International Nuclear Information System (INIS)
Brandenberger, R.
1987-01-01
Contents: Introduction; Big Bang Cosmology and its Problems; The Old and the New Inflationary Universe; The Onset of Inflation; Chaotic Inflation; The Origin of Small Scale Structure in Inflationary Universe Models: Generation of Perturbations; Gauge Invariant Analysis of Classical Perturbations; Evolution of Perturbations in Inflationary Universe Models; Cosmological Constrains on Inflationary Universe Models; Beyond the Simplest Models of Inflation; Generalized Inflation (Kaluza-Klein Inflation, Inflation in Induced Gravity Models and in Superstring Theories); Quantum Cosmology and Inflation; Inflation and Cosmic Strings: A Comparison between Two Mechanisms for Forming Structures in the Early Universe
Stability of extra dimensions in the inflating early universe
International Nuclear Information System (INIS)
Wieck, Clemens
2015-08-01
Cosmic inflation is an attractive paradigm to explain the initial conditions of the universe. It can be conveniently described by the dynamics of a single scalar field within N=1 supergravity. Due to the high energy scale during the inflationary epoch, which is favored by recent observations of the cosmic microwave background radiation, and the flatness of the inflaton potential it is necessary to consider inflation in the context of a UV-complete theory like string theory. To this end, we study the effects of moduli stabilization on inflation models in supergravity, focussing on Kahler moduli in type IIB string theory which govern the size of extra dimensions. For generic models of F-term inflation we calculate back-reaction terms by integrating out the moduli at a high energy scale. When the moduli are stabilized supersymmetrically, all effects decouple in the limit of very heavy moduli. The corrections, however, may be sizeable for realistic moduli masses above the Hubble scale and affect the predicted observables of many models like chaotic inflation and hybrid inflation. If, on the other hand, moduli stabilization entails spontaneous supersymmetry breaking, there are non-decoupling effects like soft mass terms for the inflaton. By the example of chaotic inflation we show that a careful choice of parameters and initial conditions is necessary to reconcile large-field inflation with popular moduli stabilization schemes like KKLT stabilization or the Large Volume Scenario. Furthermore, we study the interplay of moduli stabilization and D-term inflation. If inflation is driven by a constant Fayet-Iliopoulos term, the back-reaction decouples but the gravitino mass in the vacuum is surprisingly constrained. For a field-dependent Fayet-Iliopoulos term associated with an anomalous U(1) symmetry we discuss a number of obstructions to realizing inflation. Moreover, we propose a way to evade them using a new mechanism for supersymmetric moduli stabilization with world
Inflation Targeting as the Monetary Policy Framework: Bangladesh Perspective
Directory of Open Access Journals (Sweden)
Mohammed SAIFUL ISLAM
2011-06-01
Full Text Available Inflation targeting strategy has become a widely accepted monetary policy framework in many countries all over the world. Our study finds that the central bank of Bangladesh is neither inflation targeting nor does follow any other rule-guided monetary policy, rather the policy is formulated with substantial discretion under the guidelines of donor agencies. This paper provides the evidence that monetary sector of Bangladesh economy has gained considerable degree of maturity and fulfils a number of prerequisites to adopt inflation targeting strategy. Using data over 1980-2010 we estimate an error correction model in order to examine if interest rate policy could fight the inflation. This is evident that deviation in inflation from target can be corrected via the changes in interest rate. Empirical findings jointly with few descriptive statistics provide strong evidence to recommend inflation targeting as the monetary policy strategy for Bangladesh.
EXTERNAL FACTORS INFLUENCE ON INFLATION: THE CASE OF ROMANIA
Directory of Open Access Journals (Sweden)
Ihnatov Iulian
2011-07-01
Full Text Available In this paper we try to assess the main external determinants of inflation dynamics in Romania. The literature in the field of measuring inflation dynamics is wealthy and various. There are many developing country - level studies that examine inflation dynamics: Blavy (2004 - Guinea, Duma (2008 - Sri Lanka, Gottschalk et al (2008 - Sierra Leone, Moriyama (2008 - Sudan, Mwase (2006 - Tanzania, Williams and Adedeji (2004 - Dominican Republic, Hossain (2005 - Indonesia, Almounsor (2010 - Yemen. The issue of Romanian inflation dynamics is present in many and various studies, like Hammermann (2007, Pelinescu and Dospinescu (2006, Budina et al (2006 etc. There are no other recent studies that analyze the external determinants on Romanian inflation dynamics. In our paper we estimate an OLS single equation model, using a methodology derived from Almounsor (2010. The empirical analysis uses monthly data from August 2005 to January 2011. The start point of the data series is the moment of a major change in the National Bank of Romania (NBR monetary policy: adoption of the inflation targeting regime. The independent variables used in our research are: harmonized consumer price index of EU-25 countries, EUR/RON exchange rate, crude oil price index (for analyzing the external shocks effect and M2 monetary aggregate (intermediate money supply as a control variable. The outcomes suggest that inflation in Romania is driven mainly by international price shocks - harmonized consumer price index of EU-25 countries. The EUR/RON exchange rate depreciation has a small influence on domestic inflation. In the short run, the effect of the international oil price is insignificant. Money supply, used here as a control variable, is shown to have a very small effect on inflation in Romania when using OLS regressions. The results show that 66% of the domestic inflation variance is explained by the independent variables in our model.
Fear of Floating and Inflation Targeting in Turkey
Directory of Open Access Journals (Sweden)
Vasif Abiyev
2014-12-01
Full Text Available The objective of this paper is to test empirical validity of Fear of Floating hypothesis for Turkey after the adoption of Inflation Targeting. We start applying methodologies developed by Calvo and Reinhart (2002 and Ball and Reyes (2004, 2008 to check the probabilities of changes in exchange rate and monetary policy instruments before and after inflation targeting regime. We then use a VAR model to estimate exchange rate pass-through and response of monetary policy instruments to exchange rate shocks before and after inflation targeting regime. VAR model helps to understand the impacts of switch in monetary policy regime on exchange rate pass-through and foreign exchange market interventions. The paper concludes that after the adoption of inflation targeting regime, the exchange rate pass-through still matters for the attainment of inflation targets and the monetary policy do not exhibit a fear of floating practices.
Loop quantum gravity effects on inflation and the CMB
International Nuclear Information System (INIS)
Tsujikawa, Shinji; Singh, Parampreet; Maartens, Roy
2004-01-01
In loop quantum cosmology, the universe avoids a big bang singularity and undergoes an early and short super-inflation phase. During super-inflation, non-perturbative quantum corrections to the dynamics drive an inflaton field up its potential hill, thus setting the initial conditions for standard inflation. We show that this effect can raise the inflaton high enough to achieve sufficient e-foldings in the standard inflation era. We analyse the cosmological perturbations generated when slow-roll is violated after super-inflation and show that loop quantum effects can in principle leave an indirect signature on the largest scales in the CMB, with some loss of power and running of the spectral index
Understanding Inflation and Revising National Price Data
International Development Research Centre (IDRC) Digital Library (Canada)
Pete
In parallel, official inflation statistics attribute inflation to other expenditure items. Whereas ..... Finally, instead of using a fixed-based index, other methods employ non-fixed bases for ...... Furniture and Household Maintenance. 7.9. 3.9. 8.18.
76 FR 47177 - Publication of Housing Price Inflation Adjustment
2011-08-04
... DEPARTMENT OF DEFENSE Office of the Secretary Publication of Housing Price Inflation Adjustment AGENCY: Office of the Under Secretary (Personnel and Readiness), Department of Defense. ACTION: Notice... reflect inflation and to publish the new amount in the Federal Register. We have applied the inflation...
Higgs inflation and the cosmological constant
Energy Technology Data Exchange (ETDEWEB)
Jegerlehner, Fred [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2014-02-15
The Higgs not only induces the masses of all SM particles, the Higgs, given its special mass value, is the natural candidate for the inflaton and in fact is ruling the evolution of the early universe, by providing the necessary dark energy which remains the dominant energy density. SM running couplings not only allow us to extrapolate SM physics up to the Planck scale, but equally important they are triggering the Higgs mechanism. This is possible by the fact that the bare mass term in the Higgs potential changes sign at about μ{sub 0}≅1.40 x 10{sup 16} GeV and in the symmetric phase is enhanced by quadratic terms in the Planck mass. Such a huge Higgs mass term is able to play a key role in triggering inflation in the early universe. In this article we extend our previous investigation by working out the details of a Higgs inflation scenario. We show how different terms contributing to the Higgs Lagrangian are affecting inflation. Given the SM and its extrapolation to scales μ>μ{sub 0} we find a calculable cosmological constant V(0) which is weakly scale dependent and actually remains large during inflation. This is different to the Higgs fluctuation field dependent ΔV(φ), which decays exponentially during inflation, and actually would not provide a sufficient amount of inflation. The fluctuation field has a different effective mass which shifts the bare Higgs transition point to a lower value μ'{sub 0} ≅7.7 x 10{sup 14} GeV. The vacuum energy V(0) being proportional to M{sub Pl}{sup 4} has a coefficient which vanishes near the Higgs transition point, such that the bare and the renormalized cosmological constant match at this point. The role of the Higgs in reheating and baryogenesis is emphasized.
Grand unification and subcritical hybrid inflation
International Nuclear Information System (INIS)
Buchmueller, Wilfried; Ishiwata, Koji
2014-12-01
We consider hybrid inflation for small couplings of the inflaton to matter such that the critical value of the inflaton field exceeds the Planck mass. It has recently been shown that inflation then continues at subcritical inflaton field values where quantum fluctuations generate an effective inflaton mass. The effective inflaton potential interpolates between a quadratic potential at small field values and a plateau at large field values. An analysis of the allowed parameter space leads to predictions for the scalar spectral index n s and the tensor-to-scalar ratio r similar to those of natural inflation. Using the range for n s and r favoured by the Planck data, we find that the energy scale of the plateau is constrained to the interval (1.6-2.4) x 10 16 GeV which includes the energy scale of gauge coupling unification in the supersymmetric standard model. The tensor-to-scalar ratio is predicted to have the lower bound r>0.049 for 60 e-folds before the end of inflation.
Large-field inflation and supersymmetry breaking
International Nuclear Information System (INIS)
Buchmueller, Wilfried; Wieck, Clemens; Dudas, Emilian; Heurtier, Lucien; Ecole Polytechnique, Palaiseau
2014-07-01
Large-field inflation is an interesting and predictive scenario. Its non-trivial embedding in supergravity was intensively studied in the recent literature, whereas its interplay with supersymmetry breaking has been less thoroughly investigated. We consider the minimal viable model of chaotic inflation in supergravity containing a stabilizer field, and add a Polonyi field. Furthermore, we study two possible extensions of the minimal setup. We show that there are various constraints: first of all, it is very hard to couple an O'Raifeartaigh sector with the inflaton sector, the simplest viable option being to couple them only through gravity. Second, even in the simplest model the gravitino mass is bounded from above parametrically by the inflaton mass. Therefore, high-scale supersymmetry breaking is hard to implement in a chaotic inflation setup. As a separate comment we analyze the simplest chaotic inflation construction without a stabilizer field, together with a supersymmetrically stabilized Kaehler modulus. Without a modulus, the potential of such a model is unbounded from below. We show that a heavy modulus cannot solve this problem.
The hybrid inflation waterfall and the primordial curvature perturbation
International Nuclear Information System (INIS)
Lyth, David H.
2012-01-01
Without demanding a specific form for the inflaton potential, we obtain an estimate of the contribution to the curvature perturbation generated during the linear era of the hybrid inflation waterfall. The spectrum of this contribution peaks at some wavenumber k = k * , and goes like k 3 for k * , making it typically negligible on cosmological scales. The scale k * can be outside the horizon at the end of inflation, in which case ζ = −(g 2 −(g 2 )) with g gaussian. Taking this into account, the cosmological bound on the abundance of black holes is likely to be satisfied if the curvaton mass m much bigger than the Hubble parameter H, but is likely to be violated if m∼< H. Coming to the contribution to ζ from the rest of the waterfall, we are led to consider the use of the 'end-of-inflation' formula, giving the contribution to ζ generated during a sufficiently sharp transition from nearly-exponential inflation to non-inflation, and we state for the first time the criterion for the transition to be sufficiently sharp. Our formulas are applied to supersymmetric GUT inflation and to supernatural/running-mass inflation
Deriving inflation forecasts from government bond prices
Directory of Open Access Journals (Sweden)
Kožul Nataša
2014-01-01
Full Text Available In financial research and practice, it is widely accepted that nominal interest rates derived from the prices of various financial products of different maturities comprise of corresponding real interest rates and inflation. While extensive research has been conducted on the relationship between these three variables, estimation of their levels is still largely based on the industry surveys and market data. As this information only indicates the current expectations of interest rate and inflation movements over time, a number of caveats should be noted when interpreting such measures. In the US and the UK, where the government bond markets are the largest and most active, a comparative analysis between conventional government bonds and those whose yield is linked to inflation provides a measure of inflation expectations. However, as such analyses implicitly assume that investment in government bonds is virtually risk free, it is questionable whether the derived estimates are of any value in current economic conditions. Moreover, this approach cannot be generalized to other countries, where number of traded products from which any relationship between interest rates and inflation can be determined is limited and different economic conditions prevail. Thus, this paper aims to present an overview of the methodologies used to forecast inflation rates from government bond prices, drawing attention to the key assumptions and limitations of these approaches. The goal is to ascertain their accuracy, and thus their value in determining the real yields of various interest rate-linked products.
Recent Inflation of Kilauea Volcano
Miklius, A.; Poland, M.; Desmarais, E.; Sutton, A.; Orr, T.; Okubo, P.
2006-12-01
Over the last three years, geodetic monitoring networks and satellite radar interferometry have recorded substantial inflation of Kilauea's magma system, while the Pu`u `O`o eruption on the east rift zone has continued unabated. Combined with the approximate doubling of carbon dioxide emission rates at the summit during this period, these observations indicate that the magma supply rate to the volcano has increased. Since late 2003, the summit area has risen over 20 cm, and a 2.5 km-long GPS baseline across the summit area has extended almost half a meter. The center of inflation has been variable, with maximum uplift shifting from an area near the center of the caldera to the southeastern part of the caldera in 2004-2005. In 2006, the locus of inflation shifted again, to the location of the long-term magma reservoir in the southern part of the caldera - the same area that had subsided more than 1.5 meters during the last 23 years of the ongoing eruption. In addition, the southwest rift zone reversed its long-term trend of subsidence and began uplifting in early 2006. The east rift zone has shown slightly accelerated rates of extension, but with a year-long hiatus following the January 2005 south flank aseismic slip event. Inflation rates have varied greatly. Accelerated rates of extension and uplift in early 2005 and 2006 were also associated with increased seismicity. Seismicity occurred not only at inflation centers, but was also triggered on the normal faulting area northwest of the caldera and the strike-slip faulting area in the upper east rift zone. In early 2006, at about the time that we started recording uplift on the southwest rift zone, the rate of earthquakes extending from the summit into the southwest rift zone at least quadrupled. The most recent previous episode of inflation at Kilauea, in 2002, may have resulted from reduced lava- transport capacity, as it was associated with decreased outflow at the eruption site. In contrast, eruption volumes
Non-minimally coupled tachyon and inflation
International Nuclear Information System (INIS)
Piao Yunsong; Huang Qingguo; Zhang Xinmin; Zhang Yuanzhong
2003-01-01
In this Letter, we consider a model of tachyon with a non-minimal coupling to gravity and study its cosmological effects. Regarding inflation, we show that only for a specific coupling of tachyon to gravity this model satisfies observations and solves various problems which exist in the single and multi tachyon inflation models. But noting in the string theory the coupling coefficient of tachyon to gravity is of order g s , which in general is very small, we can hardly expect that the non-minimally coupling of tachyon to gravity could provide a reasonable tachyon inflation scenario. Our work may be a meaningful try for the cosmological effect of tachyon non-minimally coupled to gravity
Generic analysis of kinetically driven inflation
Saitou, Rio
2018-04-01
We perform a model-independent analysis of kinetically driven inflation (KDI) which (partially) includes generalized G-inflation and ghost inflation. We evaluate the background evolution splitting into the inflationary attractor and the perturbation around it. We also consider the quantum fluctuation of the scalar mode with a usual scaling and derive the spectral index, ignoring the contribution from the second-order products of slow-roll parameters. Using these formalisms, we find that within our generic framework the models of KDI which possess the shift symmetry of scalar field cannot create the quantum fluctuation consistent with the observation. Breaking the shift symmetry, we obtain a few essential conditions for viable models of KDI associated with the graceful exit.
Extended inflation from higher-dimensional theories
International Nuclear Information System (INIS)
Holman, R.; Kolb, E.W.; Vadas, S.L.; Wang, Y.
1991-01-01
We consider the possibility that higher-dimensional theories may, upon reduction to four dimensions, allow extended inflation to occur. We analyze two separate models. One is a very simple toy model consisting of higher-dimensional gravity coupled to a scalar field whose potential allows for a first-order phase transition. The other is a more sophisticated model incorporating the effects of nontrivial field configurations (monopole, Casimir, and fermion bilinear condensate effects) that yield a nontrivial potential for the radius of the internal space. We find that extended inflation does not occur in these models. We also find that the bubble nucleation rate in these theories is time dependent unlike the case in the original version of extended inflation
8 CFR 280.53 - Civil monetary penalties inflation adjustment.
2010-01-01
... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Civil monetary penalties inflation... REGULATIONS IMPOSITION AND COLLECTION OF FINES § 280.53 Civil monetary penalties inflation adjustment. (a) In general. In accordance with the requirements of the Federal Civil Penalties Inflation Adjustment Act of...
32 CFR 269.3 - Civil monetary penalty inflation adjustment.
2010-07-01
... 32 National Defense 2 2010-07-01 2010-07-01 false Civil monetary penalty inflation adjustment. 269... DEFENSE (CONTINUED) MISCELLANEOUS CIVIL MONETARY PENALTY INFLATION ADJUSTMENT § 269.3 Civil monetary penalty inflation adjustment. The Department shall, not later than 180 days after the enactment of the...
17 CFR 143.8 - Inflation-adjusted civil monetary penalties.
2010-04-01
... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Inflation-adjusted civil... JURISDICTION General Provisions § 143.8 Inflation-adjusted civil monetary penalties. (a) Unless otherwise amended by an act of Congress, the inflation-adjusted maximum civil monetary penalty for each violation of...
Inflation Targeting in Emerging Market Countries
Frederic S. Mishkin
2000-01-01
This paper outlines what inflation targeting involves for emerging market/transition countries and discusses the advantages and disadvantages of this monetary policy strategy. The discussion suggests that although inflation targeting is not a panacea and may not be appropriate for many emerging market countries, it can be a highly useful monetary policy strategy in a number of them.
Inflation Metaphor in Contemporary American English
Hu, Chunyu; Chen, Zhi
2015-01-01
Inflation is often regarded as a dangerous phenomenon which poses a potential threat to economies in the world. It is thus an entity that demands the constant attention of economists, policymakers and the general public. In order to make this abstract entry more concrete and vivid, a number of metaphorical expressions are used to depict inflation.…
Complex Hybrid Inflation and Baryogenesis
Delepine, David; Martinez, Carlos; Urena-Lopez, L. Arturo
2006-01-01
We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated to the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vev of the waterfall field, which is well constrained by diverse cosmological observations.
Theoretical aspects of inflation targeting
Directory of Open Access Journals (Sweden)
Obradović Jelena
2014-01-01
Full Text Available Inflation targeting is one of the possible strategies used by central banks during conducting monetary policy. The basic characteristics, advantages and disadvantages of inflation targeting will be presented in this paper. The focus is on the the presentation and interpretation of the understanding of this strategy from the perspective of monetarist and Keynesian theory, the theory of rational expectations, and methodological analysis of the strategy in light of the game theory using payoff matrix.
Some problems with extended inflation
International Nuclear Information System (INIS)
Weinberg, E.J.
1989-01-01
The recently proposed extended inflation scenario is examined. Upper bounds on the Brans-Dicke parameter ω are obtained by requiring that the recovery from the supercooled regime be such that the presently observed Universe could have emerged. These bounds are well below the present-day experimental limits, implying that one must use models which have a potential to fix the present value of the Brans-Dicke-like scalar field. The implications for extended inflation in such models are discussed
Mathematical issues in eternal inflation
Singh Kohli, Ikjyot; Haslam, Michael C.
2015-04-01
In this paper, we consider the problem of the existence and uniqueness of solutions to the Einstein field equations for a spatially flat Friedmann-Lemaître-Robertson-Walker universe in the context of stochastic eternal inflation, where the stochastic mechanism is modelled by adding a stochastic forcing term representing Gaussian white noise to the Klein-Gordon equation. We show that under these considerations, the Klein-Gordon equation actually becomes a stochastic differential equation. Therefore, the existence and uniqueness of solutions to Einstein’s equations depend on whether the coefficients of this stochastic differential equation obey Lipschitz continuity conditions. We show that for any choice of V(φ ), the Einstein field equations are not globally well-posed, hence, any solution found to these equations is not guaranteed to be unique. Instead, the coefficients are at best locally Lipschitz continuous in the physical state space of the dynamical variables, which only exist up to a finite explosion time. We further perform Feller’s explosion test for an arbitrary power-law inflaton potential and prove that all solutions to the Einstein field equations explode in a finite time with probability one. This implies that the mechanism of stochastic inflation thus considered cannot be described to be eternal, since the very concept of eternal inflation implies that the process continues indefinitely. We therefore argue that stochastic inflation based on a stochastic forcing term would not produce an infinite number of universes in some multiverse ensemble. In general, since the Einstein field equations in both situations are not well-posed, we further conclude that the existence of a multiverse via the stochastic eternal inflation mechanism considered in this paper is still very much an open question that will require much deeper investigation.
8 CFR 1280.53 - Civil monetary penalties inflation adjustment.
2010-01-01
... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Civil monetary penalties inflation... penalties inflation adjustment. (a) In general. In accordance with the requirements of the Federal Civil Penalties Inflation Adjustment Act of 1990, Pub. L. 101-410, 104 Stat. 890, as amended by the Debt...
The Determinants of Inflation in Pakistan: An Econometric Analysis
Nazima Ellahi
2017-01-01
Inflation is not just a rise in general price level, but a much more complex phenomenon. It is well admitted fact that mild inflation is natural and a greasing factor to the wheel of economy and commerce and on the other hand, high inflation causes negative impact on economy. In order to formulate policies regarding its control and keeping it at a moderate level, it is necessary to explore its major determinants. Present study is an attempt to discuss the determinants of inflation in Pakistan...
Mutated hilltop inflation: a natural choice for early universe
International Nuclear Information System (INIS)
Pal, Barun Kumar; Pal, Supratik; Basu, B.
2010-01-01
We propose a model of inflation with a suitable potential for a single scalar field which falls in the wide class of hilltop inflation. We derive the analytical expressions for most of the physical quantities related to inflation and show that all of them represent the true behavior as required from a model of inflation. We further subject the results to observational verification by formulating the theory of perturbations based on our model followed by an estimation for the values of those observable parameters. Our model is found to be in excellent agreement with observational data. Thus, the features related to the model leads us to infer that this type of hilltop inflation may be a natural choice for explaining the early universe
Inflating wormholes in the braneworld models
Energy Technology Data Exchange (ETDEWEB)
Wong, K C; Harko, T; Cheng, K S, E-mail: fankywong@gmail.com, E-mail: harko@hkucc.hku.hk, E-mail: hrspksc@hkucc.hku.hk [Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong)
2011-07-21
The braneworld model, in which our Universe is a three-brane embedded in a five-dimensional bulk, allows the existence of wormholes, without any violation of the energy conditions. A fundamental ingredient of traversable wormholes is the violation of the null energy condition (NEC). However, in the braneworld models, the stress-energy tensor confined on the brane, threading the wormhole, satisfies the NEC. In conventional general relativity, wormholes existing before inflation can be significantly enlarged by the expanding spacetime. We investigate the evolution of an inflating wormhole in the braneworld scenario, in which the wormhole is supported by the nonlocal braneworld effects. As a first step in our study, we consider the possibility of embedding a four-dimensional braneworld wormhole into a five-dimensional bulk. The conditions for the embedding are obtained by studying the junction conditions for the wormhole geometry, as well as the full set of the five-dimensional bulk field equations. For the description of the inflation, we adopt the chaotic inflation model. We study the dynamics of the braneworld wormholes during the exponential inflation stage, and in the stage of the oscillating scalar field. A particular exact solution corresponding to a zero redshift wormhole is also obtained. The resulting evolution shows that while the physical and geometrical parameters of a zero redshift wormhole decay naturally, a wormhole satisfying some very general initial conditions could turn into a black hole and exist forever.
Curvaton paradigm can accommodate multiple low inflation scales
International Nuclear Information System (INIS)
Matsuda, Tomohiro
2004-01-01
Recent arguments show that some curvaton field may generate the cosmological curvature perturbation. As the curvaton is independent of the inflaton field, there is a hope that the fine tunings of inflation models can be cured by the curvaton scenario. More recently, however, Lyth discussed that there is a strong bound for the Hubble parameter during inflation even if one assumes the curvaton scenario. Although the most serious constraint was evaded, the bound seems rather crucial for many models of a low inflation scale. In this paper we try to remove the constraint. We show that the bound is drastically modified if there were multiple stages of inflation. (letter to the editor)
Forecasting inflation with gradual regime shifts and exogenous information
DEFF Research Database (Denmark)
González, Andrés; Hubrich, Kirstin; Teräsvirta, Timo
to be forecast to form a single inflation forecast. We show, both theoretically and by simulations, how this is done by using the penalised likelihood in the estimation of model parameters. In forecasting inflation, the central bank inflation target, if it exists, is a natural example of such prior information...
Dynamical baryogenesis through complex hybrid inflation
International Nuclear Information System (INIS)
Delepine, D; MartInez, C; Urena-Lopez, L A
2008-01-01
We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U (1) global symmetry associated to the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry [1
Dynamical baryogenesis through complex hybrid inflation
Energy Technology Data Exchange (ETDEWEB)
Delepine, D; MartInez, C; Urena-Lopez, L A [Instituto de Fisica de la Universidad de Guanajuato, C.P. 37150, Leon, Guanajuato (Mexico)], E-mail: delepine@fisica.ugto.mx, E-mail: crmtz@fisica.ugto.mx, E-mail: lurena@fisica.ugto.mx
2008-06-01
We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U (1) global symmetry associated to the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry [1].
Fluctuations in models with primordial inflation
International Nuclear Information System (INIS)
Kahn, R.; Brandenberger, R.
1984-01-01
The recently proposed general framework for calculating the growth of primordial energy density fluctuations in cosmological models is applied to two models of phenomenological interest in which the cosmological evolution differs crucially from that in new inflationary universe models. Both in a model of primordial supersymmetric inflation and in Linde's proposal of chaotic inflation we verify the conjectured results. (orig.)
Inflatable antenna for earth observing systems
Wang, Hong-Jian; Guan, Fu-ling; Xu, Yan; Yi, Min
2010-09-01
This paper describe mechanical design, dynamic analysis, and deployment demonstration of the antenna , and the photogrammetry detecting RMS of inflatable antenna surface, the possible errors results form the measurement are also analysed. Ticra's Grasp software are used to predict the inflatable antenna pattern based on the coordinates of the 460 points on the parabolic surface, the final results verified the whole design process.
Technology & Mechanics Overview of Air-Inflated Fabric Structures
National Research Council Canada - National Science Library
Cavallaro, Paul V
2006-01-01
.... Examples include air ships, weather balloons, inflatable radomes, shelters, pneumatic muscles, inflatable boats, bridging, and energy absorbers such as automotive air bags and landing cushions for space vehicles...
The hybrid inflation waterfall and the primordial curvature perturbation
Lyth, David H.
2012-05-01
Without demanding a specific form for the inflaton potential, we obtain an estimate of the contribution to the curvature perturbation generated during the linear era of the hybrid inflation waterfall. The spectrum of this contribution peaks at some wavenumber k = k*, and goes like k3 for k Lt k*, making it typically negligible on cosmological scales. The scale k* can be outside the horizon at the end of inflation, in which case ζ = -(g2-langg2rang) with g gaussian. Taking this into account, the cosmological bound on the abundance of black holes is likely to be satisfied if the curvaton mass m much bigger than the Hubble parameter H, but is likely to be violated if mlsimH. Coming to the contribution to ζ from the rest of the waterfall, we are led to consider the use of the `end-of-inflation' formula, giving the contribution to ζ generated during a sufficiently sharp transition from nearly-exponential inflation to non-inflation, and we state for the first time the criterion for the transition to be sufficiently sharp. Our formulas are applied to supersymmetric GUT inflation and to supernatural/running-mass inflation. A preliminary version of this paper appeared as arXiv:1107.1681.
The hybrid inflation waterfall and the primordial curvature perturbation
Energy Technology Data Exchange (ETDEWEB)
Lyth, David H., E-mail: d.lyth@lancaster.ac.uk [Consortium for Fundamental Physics, Cosmology and Astroparticle Group, Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)
2012-05-01
Without demanding a specific form for the inflaton potential, we obtain an estimate of the contribution to the curvature perturbation generated during the linear era of the hybrid inflation waterfall. The spectrum of this contribution peaks at some wavenumber k = k{sub *}, and goes like k{sup 3} for k << k{sub *}, making it typically negligible on cosmological scales. The scale k{sub *} can be outside the horizon at the end of inflation, in which case ζ = −(g{sup 2}−(g{sup 2})) with g gaussian. Taking this into account, the cosmological bound on the abundance of black holes is likely to be satisfied if the curvaton mass m much bigger than the Hubble parameter H, but is likely to be violated if m∼
Complex Hybrid Inflation and Baryogenesis
International Nuclear Information System (INIS)
Delepine, David; Martinez, Carlos; Urena-Lopez, L. Arturo
2007-01-01
We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated with the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vacuum expectation value of the waterfall field, which is well constrained by diverse cosmological observations
Complex hybrid inflation and baryogenesis.
Delepine, David; Martínez, Carlos; Ureña-López, L Arturo
2007-04-20
We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated with the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vacuum expectation value of the waterfall field, which is well constrained by diverse cosmological observations.
A dynamical weak scale from inflation
Energy Technology Data Exchange (ETDEWEB)
You, Tevong, E-mail: tty20@cam.ac.uk [DAMTP, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)
2017-09-01
Dynamical scanning of the Higgs mass by an axion-like particle during inflation may provide a cosmological component to explaining part of the hierarchy problem. We propose a novel interplay of this cosmological relaxation mechanism with inflation, whereby the backreaction of the Higgs vacuum expectation value near the weak scale causes inflation to end. As Hubble drops, the relaxion's dissipative friction increases relative to Hubble and slows it down enough to be trapped by the barriers of its periodic potential. Such a scenario raises the natural cut-off of the theory up to ∼ 10{sup 10} GeV, while maintaining a minimal relaxion sector without having to introduce additional scanning scalars or new physics coincidentally close to the weak scale.
Cosmic Microwave Background Polarization and Inflation
Chuss, David T.
2011-01-01
Measurements of the cosmic microwave background (CMB) offer a means to explore the universe at a very early epoch. Specifically, if the universe went through a brief period of exponential expansion called inflation as current data suggest, gravitational waves from this period would polarize the CMB in a specific pattern. At GSFC, we are currently working towards two experiments that work in concert to measure this polarization pattern in search of evidence for inflation. The Cosmology Large Angular Scale Surveyor (CLASS) will measure the polarization at frequencies between 40 and 150 GHz from the Atacama Desert in Chile. The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne experiment that will make similar measurements at frequencies between 200 and 600 GHz.
No-scale SUGRA SO(10) inflation
International Nuclear Information System (INIS)
Garg, Ila
2017-01-01
We show that a renormalizable theory based on gauge group SO(10) and Higgs system 10⊕210⊕126⊕126 with no scale supergravity can lead to a Starobinsky kind of potential for inflation. Successful inflation is possible in cases where the potential during inflation corresponds to SU(3)_C×SU(2)_L×SU(2)_R×U(1)_B_−_L, SU(5)×U(1) and flipped SU(5) × U(1) symmetries with suitable choice of superpotential parameters. The reheating in such a scenario can occur via non-perturbative decay of inflaton, i.e. through ‘preheating’. After the end of reheating, when Universe cools down, the finite-temperature potential can have a minimum which corresponds to MSSM. (author)
Extended inflation from higher dimensional theories
International Nuclear Information System (INIS)
Holman, R.; Kolb, E.W.; Vadas, S.L.; Wang, Yun.
1990-04-01
The possibility is considered that higher dimensional theories may, upon reduction to four dimensions, allow extended inflation to occur. Two separate models are analayzed. One is a very simple toy model consisting of higher dimensional gravity coupled to a scalar field whose potential allows for a first-order phase transition. The other is a more sophisticated model incorporating the effects of non-trivial field configurations (monopole, Casimir, and fermion bilinear condensate effects) that yield a non-trivial potential for the radius of the internal space. It was found that extended inflation does not occur in these models. It was also found that the bubble nucleation rate in these theories is time dependent unlike the case in the original version of extended inflation
Exchange rate regimes and inflation: Evidence from India.
Mohanty, Biswajit; Bhanumurthy, N.R.
2014-01-01
Exchange rate stability is crucial for inflation management as a stable rate is expected to reduce domestic inflation pressures through a `policy discipline effect'- restricting money supply growth, and a `credibility effect'- inducing higher money demand and reduced velocity of money. Alternatively, the impossibility trillema predicts that in the presence of an open capital account, a stable exchange rate may lead to lack of control on monetary policy and, hence, higher inflation. Using a mo...
Implementing inflation targeting regimes: The case of Poland
Gottschalk, Jan; Moore, David
1999-01-01
This paper assesses the prospects for the new Polish monetary policy strategy of inflation targeting. Regarding the general requirements for implementing an inflation targeting strategy it appears that Poland has made sufficient progress in reducing fiscal dominance and hardening budget constraints. The paper also finds that the exchange rate has played a dominant role as a policy instrument, with the linkages between the short-term interest rate and inflation remaining unclear. Given this un...
Hinson, W. F.; Keafer, L. S.
1984-01-01
It is proposed that for inflatable antenna systems, technology feasibility can be demonstrated and parametric design and scalability (scale factor 10 to 20) can be validated with an experiment using a 16-m-diameter antenna attached to the Shuttle. The antenna configuration consists of a thin film cone and paraboloid held to proper shape by internal pressure and a self-rigidizing torus. The cone and paraboloid would be made using pie-shaped gores with the paraboloid being coated with aluminum to provide reflectivity. The torus would be constructed using an aluminum polyester composite that when inflated would erect to a smooth shell that can withstand loads without internal pressure.
Supersymmetric inflation: Recent progress
International Nuclear Information System (INIS)
Ovrut, B.A.; Steinhardt, P.J.
1986-01-01
The new inflationary universe scenario is, in principle, a simple and powerful approach to resolving a large number of fundamental cosmological problems. However, in order for the scenario to be considered a complete theory, one critical question remains to be answered: What is the physics responsible for the phase transition that triggers the exponential expansion (inflation) of the universe? One possibility that the authors and several other groups have been pursuing is that the physics responsible for the phase transition involves (local) supersymmetry. The goal of this paper is to review the present status of ''Supersymmetric Inflation'', particularly emphasizing some very exciting results that they recently obtained
How Inside Money Makes Inflation Costly For Most (but Gainful For Some)
William Coleman
2007-01-01
It is argued that inflation creates private incentives for (socially costly) inside money to supplant (socially costless) outside money. Consequently, the familiar 'shoe leather cost' of inflation, that operates through a reduced demand for money under inflation, is supplemented by a separate social cost of inflation that operates through an increased supply of (inside) money under inflation. It is further argued that allowance of the costliness of an inflation-induced expansion of inside mon...
Probing Inflation via Cosmic Microwave Background Polarimetry
Chuss, David T.
2008-01-01
The Cosmic Microwave Background (CMB) has been a rich source of information about the early Universe. Detailed measurements of its spectrum and spatial distribution have helped solidify the Standard Model of Cosmology. However, many questions still remain. Standard Cosmology does not explain why the early Universe is geometrically flat, expanding, homogenous across the horizon, and riddled with a small anisotropy that provides the seed for structure formation. Inflation has been proposed as a mechanism that naturally solves these problems. In addition to solving these problems, inflation is expected to produce a spectrum of gravitational waves that will create a particular polarization pattern on the CMB. Detection of this polarized signal is a key test of inflation and will give a direct measurement of the energy scale at which inflation takes place. This polarized signature of inflation is expected to be -9 orders of magnitude below the 2.7 K monopole level of the CMB. This measurement will require good control of systematic errors, an array of many detectors having the requisite sensitivity, and a reliable method for removing polarized foregrounds, and nearly complete sky coverage. Ultimately, this measurement is likely to require a space mission. To this effect, technology and mission concept development are currently underway.
Multifield consequences for D-brane inflation
International Nuclear Information System (INIS)
Dias, Mafalda; Frazer, Jonathan; Liddle, Andrew R.
2012-01-01
We analyse the multifield behaviour in D-brane inflation when contributions from the bulk are taken into account. For this purpose, we study a large number of realisations of the potential; we find the nature of the inflationary trajectory to be very consistent despite the complex construction. Inflation is always canonical and occurs in the vicinity of an inflection point. Extending the transport method to non-slow-roll and to calculate the running, we obtain distributions for observables. The spectral index is typically blue and the running positive, putting the model under moderate pressure from WMAP7 constraints. The local f NL and tensor-to-scalar ratio are typically unobservably small, though we find approximately 0.5% of realisations to give observably large local f NL . Approximating the potential as sum-separable, we are able to give fully analytic explanations for the trends in observed behaviour. Finally we find the model suffers from the persistence of isocurvature perturbations, which can be expected to cause further evolution of adiabatic perturbations after inflation. We argue this is a typical problem for models of multifield inflation involving inflection points and renders models of this type technically unpredictive without a description of reheating
Initial conditions for critical Higgs inflation
Salvio, Alberto
2018-05-01
It has been pointed out that a large non-minimal coupling ξ between the Higgs and the Ricci scalar can source higher derivative operators, which may change the predictions of Higgs inflation. A variant, called critical Higgs inflation, employs the near-criticality of the top mass to introduce an inflection point in the potential and lower drastically the value of ξ. We here study whether critical Higgs inflation can occur even if the pre-inflationary initial conditions do not satisfy the slow-roll behavior (retaining translation and rotation symmetries). A positive answer is found: inflation turns out to be an attractor and therefore no fine-tuning of the initial conditions is necessary. A very large initial Higgs time-derivative (as compared to the potential energy density) is compensated by a moderate increase in the initial field value. These conclusions are reached by solving the exact Higgs equation without using the slow-roll approximation. This also allows us to consistently treat the inflection point, where the standard slow-roll approximation breaks down. Here we make use of an approach that is independent of the UV completion of gravity, by taking initial conditions that always involve sub-planckian energies.
Non-Gaussianity from tachyonic preheating in hybrid inflation
International Nuclear Information System (INIS)
Barnaby, Neil; Cline, James M.
2007-01-01
In a previous work we showed that large non-Gaussianities and nonscale-invariant distortions in the cosmic microwave background power spectrum can be generated in hybrid inflation models, due to the contributions of the tachyon (waterfall) field to the second order curvature perturbation. Here we clarify, correct, and extend those results. We show that large non-Gaussianity occurs only when the tachyon remains light throughout inflation, whereas n=4 contamination to the spectrum is the dominant effect when the tachyon is heavy. We find constraints on the parameters of warped-throat brane-antibrane inflation from non-Gaussianity. For F-term and D-term inflation models from supergravity, we obtain nontrivial constraints from the spectral distortion effect. We also establish that our analysis applies to complex tachyon fields
Estimation of Unobserved Inflation Expectations in India using State-Space Model
Chattopadhyay, Siddhartha; Sahu, Sohini; Jha, Saakshi
2016-01-01
Inflation expectations is an important marker for monetary policy makers. India being a new entrant to the group of countries that pursue inflation targeting as its monetary policy objective, estimating the inflation expectation is of paramount importance. This paper estimates the unobserved inflation expectations in India between 1993:Q1 to 2016:Q1 from the Fisher equation relation using the state space approach (Kalman Filter). We find that our results match well with the inflation forecast...
76 FR 56294 - Inflatable Personal Flotation Devices
2011-09-13
... direct final rule, UL 1191 was revised to return this value to 10%. Another commenter expressed concern... into effect, would facilitate teens using existing inflatable PFDs, and would enable the marketing of existing inflatable PFDs to youth. The commenter also expressed concern that this rulemaking is premature...
Demystify Learning Expectations to Address Grade Inflation
Hodges, Linda C.
2014-01-01
This article describes the subject of "grade inflation," a reference to educators giving higher grades to student work than their expectations for student achievement warrant. Of the many reasons why this practice happens, Hodges specifically discusses inflating grades as "a natural consequence" when the faculty really…
The inflation-output nexus:empirical evidence from India, Brazil and South Africa
Paresh Kumar Narayan; Seema Narayan
2011-01-01
In this paper we study the relationship between output and inflation for India, Brazil, and South Africa using the EGARCH model. For India and South Africa, we find evidence for: (1) the Cukierman and Meltzer hypothesis that inflation volatility raises inflation; (2) the Friedman hypothesis that inflation raises inflation volatility; and (3) the Black hypothesis that output volatility raises output growth, and that output volatility reduces inflation. For Brazil, we do not find any evidence o...
Inflation in the Costs of Building Aircraft Carriers
2016-04-01
amount the Navy could spend on the second and following ships in the Ford class. That amount could be adjusted to account for economic inflation and...other factors. (The legislation did not clearly define “economic inflation ,” but the Navy has interpreted it to mean increases in the prices of...Actual inflation in the prices of labor and materials was the most important contributor to the rise in the cost cap, accounting for $2.5 billion of the
International Nuclear Information System (INIS)
Oh, P.; Chicago Univ., IL
1986-01-01
Cosmological solutions with three exponentially expanding space dimensions in the N=1 supersymmetric Yang-Mills supergravity system are found under the assumption of gluino and ''subgravitino'' condensation. The potential has a long flat region providing sufficient inflation. (orig.)
Cosmological perturbations in transient phantom inflation scenarios
Energy Technology Data Exchange (ETDEWEB)
Richarte, Martin G. [Universidade Federal do Parana, Departamento de Fisica, Caixa Postal 19044, Curitiba (Brazil); Universidad de Buenos Aires, Ciudad Universitaria 1428, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Kremer, Gilberto M. [Universidade Federal do Parana, Departamento de Fisica, Caixa Postal 19044, Curitiba (Brazil)
2017-01-15
We present a model of inflation where the inflaton is accommodated as a phantom field which exhibits an initial transient pole behavior and then decays into a quintessence field which is responsible for a radiation era. We must stress that the present unified model only deals with a single field and that the transition between the two eras is achieved in a smooth way, so the model does not suffer from the eternal inflation issue. We explore the conditions for the crossing of the phantom divide line within the inflationary era along with the structural stability of several critical points. We study the behavior of the phantom field within the slow-climb approximation along with the necessary conditions to have sufficient inflation. We also examine the model at the level of classical perturbations within the Newtonian gauge and determine the behavior of the gravitational potential, contrast density and perturbed field near the inflation stage and the subsequent radiation era. (orig.)
Ruling out Critical Higgs Inflation? arXiv
Masina, Isabella
We consider critical Higgs inflation, namely Higgs inflation with a rising inflection point at smaller field values than those of the plateau induced by the non-minimal coupling to gravity. It has been proposed that such configuration is compatible with the present CMB observational constraints on inflation, and also with primordial black hole production accounting for the totality or a fraction of the observed dark matter. We study the model taking into account the NNLO corrections to the Higgs effective potential: such corrections are extremely important to reduce the theoretical error associated to the calculation. We find that, in the 3 sigma window for the relevant low energy parameters, which are the strong coupling and the Higgs mass (the top mass follows by requiring an inflection point), the potential at the inflection point is so large (and so is the Hubble constant during inflation) that the present bound on the tensor-to-scalar ratio is violated. The model is viable only allowing the strong coupli...
QED vacuum loops and inflation
Energy Technology Data Exchange (ETDEWEB)
Fried, H.M. [Brown University, Department of Physics, Providence, RI (United States); Gabellini, Y. [UMR 6618 CNRS, Institut Non Lineaire de Nice, Valbonne (France)
2015-03-01
A QED-based model of a new version of vacuum energy has recently been suggested, which leads to a simple, finite, one parameter representation of dark energy. An elementary, obvious, but perhaps radical generalization is then able to describe both dark energy and inflation in the same framework of vacuum energy. One further, obvious generalization then leads to a relation between inflation and the big bang, to the automatic inclusion of dark matter, and to a possible understanding of the birth (and death) of a universe. (orig.)
QED vacuum loops and inflation
International Nuclear Information System (INIS)
Fried, H.M.; Gabellini, Y.
2015-01-01
A QED-based model of a new version of vacuum energy has recently been suggested, which leads to a simple, finite, one parameter representation of dark energy. An elementary, obvious, but perhaps radical generalization is then able to describe both dark energy and inflation in the same framework of vacuum energy. One further, obvious generalization then leads to a relation between inflation and the big bang, to the automatic inclusion of dark matter, and to a possible understanding of the birth (and death) of a universe. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Herrera, Ramón, E-mail: ramon.herrera@pucv.cl [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2950, Casilla 4059, Valparaíso (Chile)
2017-05-01
A warm inflationary universe in the context of Galileon model or G-model is studied. Under a general formalism we study the inflationary dynamics and the cosmological perturbations considering a coupling of the form G (φ, X )= g (φ) X . As a concrete example, we consider an exponential potential together with the cases in which the dissipation and Galilean coefficients are constants. Also, we study the weak regime given by the condition R <1+3 gH φ-dot , and the strong regime in which 1< R +3 gH φ-dot . Additionally, we obtain constraints on the parameters during the evolution of G-warm inflation, assuming the condition for warm inflation in which the temperature T > H , the conditions or the weak and strong regimes, together with the consistency relation r = r ( n {sub s} ) from Planck data.
Fairbairn, Malcolm; Markkanen, Tommi; Rodriguez Roman, David
2018-04-01
We consider the effect of the Gibbons-Hawking radiation on the inflaton in the situation where it is coupled to a large number of spectator fields. We argue that this will lead to two important effects - a thermal contribution to the potential and a gradual change in parameters in the Lagrangian which results from thermodynamic and energy conservation arguments. We present a scenario of hilltop inflation where the field starts trapped at the origin before slowly experiencing a phase transition during which the field extremely slowly moves towards its zero temperature expectation value. We show that it is possible to obtain enough e-folds of expansion as well as the correct spectrum of perturbations without hugely fine-tuned parameters in the potential (albeit with many spectator fields). We also comment on how initial conditions for inflation can arise naturally in this situation.
International Nuclear Information System (INIS)
Turner, M.S.
1983-01-01
The hot big bang cosmology provides a reliable accounting of the evolution of the Universe from -- 0.01 s after 'the bang' until the present (10-20 Byr after 'the bang'). This is a truly impressive achievement. There are, however, a handful of very fundamental 'cosmological facts' which the model by itself fails to elucidate. They include: the large-scale homogeneity, the isotropy, the small-scale inhomogeneity, the near critical expansion rate, the predominance of matter, the 'monopole problem', and the extremely tiny value of the present cosmological term. Inflation makes the present state of the observable Universe virtually insensitive to the initial state of the Universe. Unfortunately, at present there is no model of new inflation which both resolves the cosmological puzzles and leads to sensible particle physics. A general prescription for the cosmologically-desirable Higgs potential does exist
Effect of inflation on parametric resonance during preheating
International Nuclear Information System (INIS)
Hirai, Shiro
2002-01-01
The effect of inflation on parametric resonance during preheating is investigated. The behaviour of the preheating scalar field during inflation is investigated and is found to become squeezed in cases ranging from small-scale cases to large-scale cases. However, the positive-frequency solution is usually adopted in the initial condition of the scalar field at preheating. Although large squeezing occurs during inflation, the difference in the comoving occupation number of particles n k between two initial conditions is shown to be not so large. Rather, the ratio n k varies from 0.2 to 5.0, depending on k. In order to clarify this situation, we introduce the squeeze formulation. The squeeze parameters r and φ are calculated not only in preheating, but also in inflation. Since the squeeze parameters are calculated from inflation to preheating, we can clarify the behaviour of the parametric resonance. In preheating, the behaviour of r is shown to remain relatively unchanged with respect to k; however, the squeeze angle φ displays different behaviour for large-scale cases and small-scale cases
Portfolio Management with Stochastic Interest Rates and Inflation Ambiguity
DEFF Research Database (Denmark)
Munk, Claus; Rubtsov, Alexey Vladimirovich
We solve a stock-bond-cash portfolio choice problem for a risk- and ambiguity-averse investor in a setting where the inflation rate and interest rates are stochastic. The expected inflation rate is unobservable, but the investor may learn about it from realized inflation and observed stock and bond......-Jacobi-Bellman equation in closed form and derive and illustrate a number of interesting properties of the solution. For example, ambiguity aversion affects the optimal portfolio through the correlation of price level with the stock index, a bond, and the expected inflation rate. Furthermore, unlike other settings...
Ho, Chiu Man; Kephart, Thomas W.
2010-01-01
We consider a 4+N dimensional Einstein gravity coupled to a non-linear sigma model. This theory admits a solution in which the N extra dimensions contract exponentially while the ordinary space expand exponentially. Physically, the non-linear sigma fields induce the dynamical compactification of the extra dimensions, which in turn drives inflation. No inflatons are required.
Zero inflated negative binomial-generalized exponential distributionand its applications
Directory of Open Access Journals (Sweden)
Sirinapa Aryuyuen
2014-08-01
Full Text Available In this paper, we propose a new zero inflated distribution, namely, the zero inflated negative binomial-generalized exponential (ZINB-GE distribution. The new distribution is used for count data with extra zeros and is an alternative for data analysis with over-dispersed count data. Some characteristics of the distribution are given, such as mean, variance, skewness, and kurtosis. Parameter estimation of the ZINB-GE distribution uses maximum likelihood estimation (MLE method. Simulated and observed data are employed to examine this distribution. The results show that the MLE method seems to have high efficiency for large sample sizes. Moreover, the mean square error of parameter estimation is increased when the zero proportion is higher. For the real data sets, this new zero inflated distribution provides a better fit than the zero inflated Poisson and zero inflated negative binomial distributions.
New mechanism for generating density perturbations from inflation
International Nuclear Information System (INIS)
Dvali, Gia; Gruzinov, Andrei; Zaldarriaga, Matias
2004-01-01
We propose a new mechanism to generate density perturbations in inflationary models. Spatial fluctuations in the decay rate of the inflaton field to ordinary matter lead to fluctuations in the reheating temperature. We argue that in most realistic models of inflation the coupling of the inflaton to normal matter is determined by the vacuum expectation values of fields in the theory. If those fields are light during inflation (this is a generic situation in the minimal models of supersymmetric inflation) they will fluctuate leading to density perturbations through the proposed mechanism. We show that these fluctuations could easily dominate over the ones generated through the standard mechanism. The new scenario has several consequences for inflation model building and observations. The proposed mechanism allows us to generate the observed level of density perturbations with a much lower scale of inflation and thus generically predicts a smaller level of gravitational waves. The relation between the slope of the spectrum of the produced density perturbations and the potential of the inflaton field is different from the standard relations obtained in the context of slow roll inflation. Because the field responsible for the fluctuations is not the inflaton, it can have significantly larger self-couplings and thus density perturbations could be non-Gaussian. The non-Gaussianity can be large enough to be detectable by CMB and large scale structure observations
77 FR 19937 - Inflatable Personal Flotation Devices
2012-04-03
... Advancement Act OMB Office of Management and Budget PFD Personal flotation device STP Standards Technical... using existing inflatable PFDs, and would enable marketing of existing inflatable PFDs to youth. The... approved, and thus does not affect the availability, use, or marketing of existing PFDs to or by the youth...
Primordial two-component maximally symmetric inflation
Enqvist, K.; Nanopoulos, D. V.; Quirós, M.; Kounnas, C.
1985-12-01
We propose a two-component inflation model, based on maximally symmetric supergravity, where the scales of reheating and the inflation potential at the origin are decoupled. This is possible because of the second-order phase transition from SU(5) to SU(3)×SU(2)×U(1) that takes place when φ≅φcinflation at the global minimum, and leads to a reheating temperature TR≅(1015-1016) GeV. This makes it possible to generate baryon asymmetry in the conventional way without any conflict with experimental data on proton lifetime. The mass of the gravitinos is m3/2≅1012 GeV, thus avoiding the gravitino problem. Monopoles are diluted by residual inflation in the broken phase below the cosmological bounds if φcUSA.
Pole inflation in Jordan frame supergravity
Energy Technology Data Exchange (ETDEWEB)
Saikawa, Ken' ichi [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yamaguchi, Masahide [Tokyo Institute of Technology, Ookayama (Japan). Dept. of Physics; Yamashita, Yasuho [Kyoto Univ. (Japan). Yukawa Inst. for Theoretical Physics; Yoshida, Daisuke [Montreal Univ., QC (Canada). Dept. of Physics
2017-09-15
We investigate inflation models in Jordan frame supergravity, in which an inflaton non-minimally couples to the scalar curvature. By imposing the condition that an inflaton would have the canonical kinetic term in the Jordan frame, we construct inflation models with asymptotically flat potential through pole inflation technique and discuss their relation to the models based on Einstein frame supergravity. We also show that the model proposed by Ferrara et al. has special position and the relation between the Kaehler potential and the frame function is uniquely determined by requiring that scalars take the canonical kinetic terms in the Jordan frame and that a frame function consists only of a holomorphic term (and its anti-holomorphic counterpart) for symmetry breaking terms. Our case corresponds to relaxing the latter condition.
Global embedding of fibre inflation models
Energy Technology Data Exchange (ETDEWEB)
Cicoli, Michele [Dipartimento di Fisica e Astronomia, Università di Bologna,via Irnerio 46, 40126 Bologna (Italy); INFN - Sezione di Bologna,viale Berti Pichat 6/2, 40127 Bologna (Italy); Abdus Salam ICTP,Strada Costiera 11, Trieste 34151 (Italy); Muia, Francesco [Rudolf Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Rd., Oxford OX1 3NP (United Kingdom); Shukla, Pramod [Abdus Salam ICTP,Strada Costiera 11, Trieste 34151 (Italy)
2016-11-30
We present concrete embeddings of fibre inflation models in globally consistent type IIB Calabi-Yau orientifolds with closed string moduli stabilisation. After performing a systematic search through the existing list of toric Calabi-Yau manifolds, we find several examples that reproduce the minimal setup to embed fibre inflation models. This involves Calabi-Yau manifolds with h{sup 1,1}=3 which are K3 fibrations over a ℙ{sup 1} base with an additional shrinkable rigid divisor. We then provide different consistent choices of the underlying brane set-up which generate a non-perturbative superpotential suitable for moduli stabilisation and string loop corrections with the correct form to drive inflation. For each Calabi-Yau orientifold setting, we also compute the effect of higher derivative contributions and study their influence on the inflationary dynamics.
Pole inflation in Jordan frame supergravity
International Nuclear Information System (INIS)
Saikawa, Ken'ichi; Yamaguchi, Masahide; Yamashita, Yasuho; Yoshida, Daisuke
2017-09-01
We investigate inflation models in Jordan frame supergravity, in which an inflaton non-minimally couples to the scalar curvature. By imposing the condition that an inflaton would have the canonical kinetic term in the Jordan frame, we construct inflation models with asymptotically flat potential through pole inflation technique and discuss their relation to the models based on Einstein frame supergravity. We also show that the model proposed by Ferrara et al. has special position and the relation between the Kaehler potential and the frame function is uniquely determined by requiring that scalars take the canonical kinetic terms in the Jordan frame and that a frame function consists only of a holomorphic term (and its anti-holomorphic counterpart) for symmetry breaking terms. Our case corresponds to relaxing the latter condition.
RE-INFLATED WARM JUPITERS AROUND RED GIANTS
Energy Technology Data Exchange (ETDEWEB)
Lopez, Eric D. [Institute for Astronomy, Royal Observatory Edinburgh, University of Edinburgh, Blackford Hill, Edinburgh (United Kingdom); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)
2016-02-10
Since the discovery of the first transiting hot Jupiters, models have sought to explain the anomalously large radii of highly irradiated gas giants. We now know that the size of hot Jupiter radius anomalies scales strongly with a planet's level of irradiation and numerous models like tidal heating, ohmic dissipation, and thermal tides have since been developed to help explain these inflated radii. In general, however, these models can be grouped into two broad categories: models that directly inflate planetary radii by depositing a fraction of the incident irradiation into the interior and models that simply slow a planet's radiative cooling, allowing it to retain more heat from formation and thereby delay contraction. Here we present a new test to distinguish between these two classes of models. Gas giants orbiting at moderate orbital periods around post-main-sequence stars will experience enormous increases to their irradiation as their host stars move up the sub-giant and red-giant branches. If hot Jupiter inflation works by depositing irradiation into the planet's deep interiors then planetary radii should increase in response to the increased irradiation. This means that otherwise non-inflated gas giants at moderate orbital periods of >10 days can re-inflate as their host stars evolve. Here we explore the circumstances that can lead to the creation of these “re-inflated” gas giants and examine how the existence or absence of such planets can be used to place unique constraints on the physics of the hot Jupiter inflation mechanism. Finally, we explore the prospects for detecting this potentially important undiscovered population of planets.
A toy model for single field open inflation
International Nuclear Information System (INIS)
Vaudrevange, Pascal M.; Westphal, Alexander
2012-05-01
Inflation in an open universe produced by Coleman-De Luccia (CDL) tunneling induces a friction term that is strong enough to allow for successful small-field inflation in models that would otherwise suffer from a severe overshoot problem. In this paper, we present a polynomial scalar potential which allows for a full analysis. This provides a simple model of single-field open inflation on a small-field inflection point after tunneling. We present numerical results and compare them with analytic approximations.
Impact of inflation on the macroeconomic indicators in transition economies
Directory of Open Access Journals (Sweden)
Ranković Marko
2012-06-01
Full Text Available This paper is dealing with treats of inflation in times of world financial turmoil. It examines how inflation is impacting macroeconomic factors. Is there relationship and how strong it is between inflation and economic growth, unemployment rate and other selected economic indicators? Motivated by these questions, this paper examines the relationship between inflation and selected macroeconomic indicators: real GDP annual growth rate, privatization revenues, as part of the GDP, level of investments, unemployment rate and share of assets of foreign banks in domestic bank system by using data for 13 transition economies over the period 1993-2008. The evidence strongly supports the view that the relationship between inflation and selected macroeconomic indicators is significantly and strongly negative, observed for the region. However, for small number countries in transition there is no direct significant relationship between inflation, but indirect relationship has been showed.
Inflation and Instability of a Polymeric Membrane
DEFF Research Database (Denmark)
Neergaard, Jesper; Hassager, Ole
1999-01-01
We consider an axisymmetric polymeric membrane inflated by a uniform pressure difference acting across the membrane. The polymeric materialis described by an arbitrary combination of a viscoelastic and a purely viscous component to the stress. Some viscoelastic materials described by a Mooney......-Rivlin model show a monotone increasingpressure during inflation of a spherical membrane. These materials develop a homogeneous membrane thickness in agreement with the Considere-Pearson condition. Molecularly based models such as the neo-Hookean, Doi-Edwards or Tom-Pom model show a pressure maximum when...... inflated. Membranesdescribed by these models develop a local thinning of the membrane which may lead to bursting in finite time....
Spacetime Curvature and Higgs Stability after Inflation.
Herranen, M; Markkanen, T; Nurmi, S; Rajantie, A
2015-12-11
We investigate the dynamics of the Higgs field at the end of inflation in the minimal scenario consisting of an inflaton field coupled to the standard model only through the nonminimal gravitational coupling ξ of the Higgs field. Such a coupling is required by renormalization of the standard model in curved space, and in the current scenario also by vacuum stability during high-scale inflation. We find that for ξ≳1, rapidly changing spacetime curvature at the end of inflation leads to significant production of Higgs particles, potentially triggering a transition to a negative-energy Planck scale vacuum state and causing an immediate collapse of the Universe.
Large non-Gaussianity in non-minimal inflation
Gong, Jinn-Ouk
2011-01-01
We consider a simple inflation model with a complex scalar field coupled to gravity non-minimally. Both the modulus and the angular directions of the complex scalar are slowly rolling, leading to two-field inflation. The modulus direction becomes flat due to the non-minimal coupling, and the angular direction becomes a pseudo-Goldstone boson from a small breaking of the global U(1) symmetry. We show that large non-Gaussianity can be produced during slow-roll inflation under a reasonable assumption on the initial condition of the angular direction. This scenario may be realized in particle physics models such as the Standard Model with two Higgs doublets.
Instability of capitalism inflation, unemployment, and business cycles
Directory of Open Access Journals (Sweden)
Adil H. Mouhammed
2006-12-01
Full Text Available This paper investigates the instability of capitalism defined as a condition under which capitalism creates inflation, unemployment, and business cycles. Great economists such as Marx, Veblen, and Schumpeter have examined this problem, concluding that capitalist instability will transform capitalism. A model is developed in this paper to investigate instability, and the finding is that the basic causebehind instability is the conflict on income share: wages and profits. The fluctuations in the share of profits create inflation, unemployment, and business cycles. This generalization has been verified by using data from the American economy for the 1970s, 1980s, and the 1990s. Over this period, the paper concludes, whenthe profit share is high, moderate inflation and employment were generated, and when profit share is low, inflation, unemployment, and business cycles have appeared.
The Starobinsky model from superconformal D-term inflation
International Nuclear Information System (INIS)
Buchmuller, W.; Domcke, V.; Kamada, K.
2013-06-01
We point out that in the large field regime, the recently proposed superconformal D-term inflation model coincides with the Starobinsky model. In this regime, the inflaton field dominates over the Planck mass in the gravitational kinetic term in the Jordan frame. Slow-roll inflation is realized in the large field regime for sufficiently large gauge couplings. The Starobinsky model generally emerges as an effective description of slow-roll inflation if a Jordan frame exists where, for large inflaton field values, the action is scale invariant and the ratio λ of the inflaton self-coupling and the nonminimal coupling to gravity is tiny. The interpretation of this effective coupling is different in different models. In superconformal D-term inflation it is determined by the scale of grand unification, λ∝(Λ GUT /M P ) 4 .
Inflation with light Weyl ghost
Directory of Open Access Journals (Sweden)
Tokareva Anna
2016-01-01
Full Text Available Inflationary perturbations are considered in a renormalizable but non-unitary theory of gravity with the additional Weyl term. We obtained that ghost degrees of freedom do not spoil the inflation and the scalar perturbation amplitude at the linear level even in a case of the ghost with mass smaller than Hubble parameter at inflation. The ghost impact to the observables is also estimated to be negligible for the range of masses allowed by the experiment. The non-linear level of the theory and its possible application are also discussed.
Grade Inflation: An Issue for Higher Education?
Caruth, Donald L.; Caruth, Gail D.
2013-01-01
Grade inflation impacts university credibility, student courses of study, choices of institution, and other areas. There has been an upward shift in grades without a corresponding upward shift in knowledge gained. Some of the most frequently mentioned causes of grade inflation are: (1) student evaluations of professors; (2) student teacher…
Inflation, large scale structure and particle physics
Indian Academy of Sciences (India)
Logo of the Indian Academy of Sciences ... Hybrid inflation; Higgs scalar field; structure formation; curvation. ... We then discuss a particle physics model of supersymmetric hybrid inflation at the intermediate scale in which ... May 2018. Home · Volumes & Issues · Special Issues · Forthcoming Articles · Search · Editorial Board ...
Eternal inflation and the quantum birth of cosmic structure
Energy Technology Data Exchange (ETDEWEB)
Leon, Gabriel [Universidad Nacional de La Plata, Grupo de Astrofisica, Relatividad y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, La Plata (Argentina); Universidad de Buenos Aires, Ciudad Universitaria-Pab. I, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)
2017-10-15
We consider the eternal inflation scenario of the slow-roll/chaotic type with the additional element of an objective collapse of the wave function. The incorporation of this new agent to the traditional inflationary setting might represent a possible solution to the quantum measurement problem during inflation, a subject that has not reached a consensus among the community. Specifically, it could provide an explanation for the generation of the primordial anisotropies and inhomogeneities, starting from a perfectly symmetric background and invoking symmetric dynamics. We adopt the continuous spontaneous localization model, in the context of inflation, as the dynamical reduction mechanism that generates the primordial inhomogeneities. Furthermore, when enforcing the objective reduction mechanism, the condition for eternal inflation can be bypassed. In particular, the collapse mechanism incites the wave function, corresponding to the inflaton, to localize itself around the zero mode of the field. Then the zero mode will evolve essentially unperturbed, driving inflation to an end in any region of the Universe where inflation occurred. Also, our approach achieves a primordial spectrum with an amplitude and shape consistent with the one that best fits the observational data. (orig.)
A test of inflated zeros for Poisson regression models.
He, Hua; Zhang, Hui; Ye, Peng; Tang, Wan
2017-01-01
Excessive zeros are common in practice and may cause overdispersion and invalidate inference when fitting Poisson regression models. There is a large body of literature on zero-inflated Poisson models. However, methods for testing whether there are excessive zeros are less well developed. The Vuong test comparing a Poisson and a zero-inflated Poisson model is commonly applied in practice. However, the type I error of the test often deviates seriously from the nominal level, rendering serious doubts on the validity of the test in such applications. In this paper, we develop a new approach for testing inflated zeros under the Poisson model. Unlike the Vuong test for inflated zeros, our method does not require a zero-inflated Poisson model to perform the test. Simulation studies show that when compared with the Vuong test our approach not only better at controlling type I error rate, but also yield more power.
Inflation and quantum cosmology
International Nuclear Information System (INIS)
Linde, A.
1990-01-01
We investigate an interplay between elementary particle physics, quantum cosmology and inflation. These results obtained within this approach are compared with the results obtained in the context of Euclidean quantum cosmology. In particular, we discuss relations between the stochastic approach to inflationary cosmology and the approaches based on the investigation of the Hartle-Hawking and tunneling wave functions of the universe. We argue that neither of these wave functions can be used for a complete description of the inflationary universe, but in certain cases they can be used for a description of some particular stages of inflation. It is shown that if the present vacuum energy density ρ υ exceeds some extremely small critical value ρ c (ρ c ∼ 10 -107 ) g cm -3 for chaotic inflation in the theory 1/2m 2 φ 2 ), then the lifetime of mankind in the inflationary universe should be finite, even though the universe as a whole will exist without end. A possible way to justify the anthropic principle in the context of the baby universe theory and to apply it to the evaluation of masses of elementary particles, of their coupling constants and of the vacuum energy density is also discussed. (author)
What do the shadow rates tell us about future inflation?
Kuusela, Annika; Hännikäinen, Jari
2017-01-01
This paper investigates whether shadow interest rates contain predictive power for U.S. inflation in a data-rich environment. We find that shadow rates are useful leading indicators of inflation. Shadow rates contain substantial in-sample and out-of-sample predictive power for inflation in both the zero lower bound (ZLB) and non-ZLB periods. We find that the shadow rate suggested by Wu and Xia (2016) contains more information about future inflation than the shadow rate suggested by Krippner (...
Hilltop Supernatural Inflation
Lin, C.
In this talk, I will explain how to reduce the spectral index to be n_s = 0.96 for supernatural inflation. I will also show the constraint to the reheating temperature from Big Bang Nucleosynthesis of both thermal and non-thermal gravitino production.
Inflation Metaphor in the TIME Magazine Corpus
Hu, Chunyu; Liu, Huijie
2016-01-01
A historical perspective on economy metaphor can shed new lights on economic thoughts. Based on the TIME Magazine Corpus (TMC), this paper investigates inflation metaphor over 83 years and compares findings against the economic data over the relatively corresponding period. The results show how inflation, an abstract concept and a normal economic…
The Role of Inflation-Linked Bonds. Increasing, but Still Modest
Westerhout, Ed; Ciocyte, Ona
2017-01-01
Although the market for inflation-linked bonds has expanded enormously, nominal bonds are still the main instrument to finance public debts. This paper seeks to explain why. It focuses on the Eurozone countries for which the standard argument that inflation-linked bonds may help to reduce inflation
Reconstruction of Orion Engineering Development Unit (EDU) Parachute Inflation Loads
Ray, Eric S.
2013-01-01
The process of reconstructing inflation loads of Capsule Parachute Assembly System (CPAS) has been updated as the program transitioned to testing Engineering Development Unit (EDU) hardware. The equations used to reduce the test data have been re-derived based on the same physical assumptions made by simulations. Due to instrumentation challenges, individual parachute loads are determined from complementary accelerometer and load cell measurements. Cluster inflations are now simulated by modeling each parachute individually to better represent different inflation times and non-synchronous disreefing. The reconstruction procedure is tailored to either infinite mass or finite mass events based on measurable characteristics from the test data. Inflation parameters are determined from an automated optimization routine to reduce subjectivity. Infinite mass inflation parameters have been re-defined to avoid unrealistic interactions in Monte Carlo simulations. Sample cases demonstrate how best-fit inflation parameters are used to generate simulated drag areas and loads which favorably agree with test data.
Higgs Inflation, Reheating and Gravitino Production in No-Scale Supersymmetric GUTs
Ellis, John; Xianyu, Zhong-Zhi
2016-08-30
We extend our previous study of supersymmetric Higgs inflation in the context of no-scale supergravity and grand unification, to include models based on the flipped SU(5) and the Pati-Salam group. Like the previous SU(5) GUT model, these yield a class of inflation models whose inflation predictions interpolate between those of the quadratic chaotic inflation and Starobinsky-like inflation, while also avoiding tension with proton decay limits. We further analyse the reheating process in these models, and derive the number of $e$-folds, which is independent of the reheating temperature. We derive the corresponding predictions for the scalar tilt and the tensor-to-scalar ratio in cosmic microwave background perturbations, and also discuss gravitino production following inflation.
Solving the tension between high-scale inflation and axion isocurvature perturbations
International Nuclear Information System (INIS)
Higaki, Tetsutaro; Takahashi, Fuminobu; Tokyo Univ., Kashiwa
2014-03-01
The BICEP2 experiment determined the Hubble parameter during inflation to be about 10 14 GeV. Such high inflation scale is in tension with the QCD axion dark matter if the Peccei-Quinn (PQ) symmetry remains broken during and after inflation, because too large axion isocurvature perturbations would be generated. The axion isocurvature perturbations can be suppressed if the axion acquires a sufficiently heavy mass during inflation. We show that this is realized if the PQ symmetry is explicitly broken down to a discrete symmetry and if the breaking is enhanced during inflation. We also show that, even when the PQ symmetry becomes spontaneously broken after inflation, such a temporarily enhanced PQ symmetry breaking relaxes the constraint on the axion decay constant.
Higgs inflation, reheating and gravitino production in no-scale Supersymmetric GUTs
Energy Technology Data Exchange (ETDEWEB)
Ellis, John [Theoretical Particle Physics and Cosmology Group,Department of Physics, King’s College London,London WC2R 2LS (United Kingdom); Theoretical Physics Department, CERN,CH-1211 Geneva 23 (Switzerland); He, Hong-Jian [Institute of Modern Physics and Center for High Energy Physics, Tsinghua University,Beijing 100084 (China); Center for High Energy Physics, Peking University,Beijing 100871 (China); Xianyu, Zhong-Zhi [Center of Mathematical Sciences and Applications andDepartment of Physics, Harvard University,Massachusetts 02138 (United States)
2016-08-30
We extend our previous study of supersymmetric Higgs inflation in the context of no-scale supergravity and grand unification, to include models based on the flipped SU(5) and the Pati-Salam group. Like the previous SU(5) GUT model, these yield a class of inflation models whose inflation predictions interpolate between those of the quadratic chaotic inflation and Starobinsky-like inflation, while avoiding tension with proton decay limits. We further analyse the reheating process in these models, and derive the number of e-folds, which is independent of the reheating temperature. We derive the corresponding predictions for the scalar tilt and the tensor-to-scalar ratio in cosmic microwave background perturbations, as well as discussing the gravitino production following inflation.
International Nuclear Information System (INIS)
Steinhardt, P.J.; Accetta, F.S.
1990-01-01
We present a dynamical mechanism for completing inflationary phase transitions via bubble nucleation which can satisfy all known constraints for a wide spectrum of models and parameters. The approach is a generalization of the recent ''extended inflation'' model which corrects a serious flaw. We find an essentially model-independent bubble-size distribution which may be important for large-scale structure
Multifield consequences for D-brane inflation
Energy Technology Data Exchange (ETDEWEB)
Dias, Mafalda; Frazer, Jonathan; Liddle, Andrew R., E-mail: m.dias@sussex.ac.uk, E-mail: j.frazer@sussex.ac.uk, E-mail: a.liddle@sussex.ac.uk [Astronomy Centre, University of Sussex, Brighton BN1 9QH (United Kingdom)
2012-06-01
We analyse the multifield behaviour in D-brane inflation when contributions from the bulk are taken into account. For this purpose, we study a large number of realisations of the potential; we find the nature of the inflationary trajectory to be very consistent despite the complex construction. Inflation is always canonical and occurs in the vicinity of an inflection point. Extending the transport method to non-slow-roll and to calculate the running, we obtain distributions for observables. The spectral index is typically blue and the running positive, putting the model under moderate pressure from WMAP7 constraints. The local f{sub NL} and tensor-to-scalar ratio are typically unobservably small, though we find approximately 0.5% of realisations to give observably large local f{sub NL}. Approximating the potential as sum-separable, we are able to give fully analytic explanations for the trends in observed behaviour. Finally we find the model suffers from the persistence of isocurvature perturbations, which can be expected to cause further evolution of adiabatic perturbations after inflation. We argue this is a typical problem for models of multifield inflation involving inflection points and renders models of this type technically unpredictive without a description of reheating.
Power suppression at large scales in string inflation
Energy Technology Data Exchange (ETDEWEB)
Cicoli, Michele [Dipartimento di Fisica ed Astronomia, Università di Bologna, via Irnerio 46, Bologna, 40126 (Italy); Downes, Sean; Dutta, Bhaskar, E-mail: mcicoli@ictp.it, E-mail: sddownes@physics.tamu.edu, E-mail: dutta@physics.tamu.edu [Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX, 77843-4242 (United States)
2013-12-01
We study a possible origin of the anomalous suppression of the power spectrum at large angular scales in the cosmic microwave background within the framework of explicit string inflationary models where inflation is driven by a closed string modulus parameterizing the size of the extra dimensions. In this class of models the apparent power loss at large scales is caused by the background dynamics which involves a sharp transition from a fast-roll power law phase to a period of Starobinsky-like slow-roll inflation. An interesting feature of this class of string inflationary models is that the number of e-foldings of inflation is inversely proportional to the string coupling to a positive power. Therefore once the string coupling is tuned to small values in order to trust string perturbation theory, enough e-foldings of inflation are automatically obtained without the need of extra tuning. Moreover, in the less tuned cases the sharp transition responsible for the power loss takes place just before the last 50-60 e-foldings of inflation. We illustrate these general claims in the case of Fibre Inflation where we study the strength of this transition in terms of the attractor dynamics, finding that it induces a pivot from a blue to a redshifted power spectrum which can explain the apparent large scale power loss. We compute the effects of this pivot for example cases and demonstrate how magnitude and duration of this effect depend on model parameters.
Signals of inflation in a friendly string landscape
International Nuclear Information System (INIS)
March-Russell, John; Riva, Francesco
2006-01-01
Following Freivogel et al we consider inflation in a predictive (or 'friendly') region of the landscape of string vacua, as modeled by Arkani-Hamed, Dimopoulos and Kachru. In such a region the dimensionful coefficients of super-renormalizable operators unprotected by symmetries, such as the vacuum energy and scalar mass-squareds are freely scanned over, and the objects of study are anthropically or 'environmentally' conditioned probability distributions for observables. In this context we study the statistical predictions of (inverted) hybrid inflation models, where the properties of the inflaton are probabilistically distributed. We derive the resulting distributions of observables, including the deviation from flatness 1-Ω, the spectral index of scalar cosmological perturbations n s (and its scale dependence dn s /dlog k), and the ratio of tensor to scalar perturbations r. The environmental bound on the curvature implies a solution to the η-problem of inflation with the predicted distribution of (1-n s ) indicating values close to current observations. We find a relatively low probability (< 3%) of 'just-so' inflation with measurable deviations from flatness. Intermediate scales of inflation are preferred in these models
What Causes Inflation in a Post Communist Economy? Evidence from Ethiopia
Directory of Open Access Journals (Sweden)
Dejene Mamo Bekana
2016-09-01
Full Text Available This paper examines the determinants of inflation for a post communist economy, in the long run as well as in the short run, using time series evidence from Ethiopia and applying the Johnson co integration and Error Correction Mechanisms. A vivid observation of the results shows that the short run determinants of inflation are broad money supply, growth of domestic gross product, real interest rate, budget deficit, Exchange rate, inflation expectation and world price movements. The result of the long run model after co integration is proved using the residual based ducky fuller test and the Johnson co integration tests revealed that broad money supply, government budget deficit, exchange rate and inflation expectation are found to be the major determinants of inflation. The result shows that domestic gross product growth rate has no effect on inflation. To curb inflation, therefore, policy makers need to implement prudential fiscal and monetary policy tools. Inflation expectations need to be tackled by way of transparent and well informed government policies to change consumer perception. Concerning this, it is important to consider targeting monetary and fiscal policy variables and appropriately implanting the set targets.
MONETARY POLICY AND INFLATION TARGETING IN A SMALL OPEN ECONOMY
Directory of Open Access Journals (Sweden)
Antoni Antoni
2011-09-01
Full Text Available The danger of inflation has been the focus of many central banks. This paper analyzes the transmission mechanism of monetary policy and inflation targeting in Malaysia with a backward-looking aggregate supply and demand analysis. The manage floating regime applied in the country has an important role in achieving a stable exchange rate against its major trading partners. It also analyzes the policy of maintaining the soundness of interest rate to perceive inflation targeting to increase its economic growth. Using 1991-2004 data and a traditional structural econometric model, it shows that output gap is important in forecasting a domestic inflation rate by controlling the interest rate. Keywords: Inflation targeting, monetary economics, structural econometric modelJEL classification numbers: E3, E52
Internal and external quasicrystal inflation center and their scaling factors
International Nuclear Information System (INIS)
Masakova, Z.; Patera, J.; Pelantova, E.
1998-01-01
The properties of quasicrystals of the cut and project type - namely, self-similarities or so-called inflation properties - are studied. A complete description is given for centers of the scaling symmetry of a quasicrystal, and the relevant scaling factors are determined for each 'inflation center'. If the center is a quasicrystal point, it is called an 'internal inflation center'; otherwise, it is an 'external' one. It turns out that, for any quasicrystal point u, the set of appropriate scaling factors is a u-dependent one-dimensional quasicrystal. There are infinitely many scaling factors common to all internal inflation centers. The description of external inflation centers, which are plentiful in any quasicrystal, is a slight modification of a similar description for the interval ones
The Starobinsky model from superconformal D-term inflation
Energy Technology Data Exchange (ETDEWEB)
Buchmuller, W.; Domcke, V.; Kamada, K.
2013-06-15
We point out that in the large field regime, the recently proposed superconformal D-term inflation model coincides with the Starobinsky model. In this regime, the inflaton field dominates over the Planck mass in the gravitational kinetic term in the Jordan frame. Slow-roll inflation is realized in the large field regime for sufficiently large gauge couplings. The Starobinsky model generally emerges as an effective description of slow-roll inflation if a Jordan frame exists where, for large inflaton field values, the action is scale invariant and the ratio {lambda} of the inflaton self-coupling and the nonminimal coupling to gravity is tiny. The interpretation of this effective coupling is different in different models. In superconformal D-term inflation it is determined by the scale of grand unification, {lambda}{proportional_to}({Lambda}{sub GUT}/M{sub P}){sup 4}.
Gravitino problem in minimal supergravity inflation
Energy Technology Data Exchange (ETDEWEB)
Hasegawa, Fuminori [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Mukaida, Kyohei [Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Nakayama, Kazunori [Department of Physics, Faculty of Science, The University of Tokyo, Bunkyo-ku, Tokyo 133-0033 (Japan); Terada, Takahiro, E-mail: terada@kias.re.kr [School of Physics, Korea Institute for Advanced Study (KIAS), Seoul 02455 (Korea, Republic of); Yamada, Yusuke [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94305 (United States)
2017-04-10
We study non-thermal gravitino production in the minimal supergravity inflation. In this minimal model utilizing orthogonal nilpotent superfields, the particle spectrum includes only graviton, gravitino, inflaton, and goldstino. We find that a substantial fraction of the cosmic energy density can be transferred to the longitudinal gravitino due to non-trivial change of its sound speed. This implies either a breakdown of the effective theory after inflation or a serious gravitino problem.
Finite temperature effects in primordial inflation
Gelmini, G. B.; Nanopoulos, D. V.; Olive, K. A.
1983-11-01
We present a detailed study of a recently proposed model for primordial inflation based on an N=1 locally supersymmetric potential. For a large class of parameters with which all cosmological constraints are satisfied, the temperature corrections can be neglected during the inflation period. At higher temperatures, the minimum is not at the origin, but very close to it. Address after July 1, 1983: Theory Group, Fermilab, PO Box 500, Batavia, IL 60510, USA.
Gravitino problem in minimal supergravity inflation
Directory of Open Access Journals (Sweden)
Fuminori Hasegawa
2017-04-01
Full Text Available We study non-thermal gravitino production in the minimal supergravity inflation. In this minimal model utilizing orthogonal nilpotent superfields, the particle spectrum includes only graviton, gravitino, inflaton, and goldstino. We find that a substantial fraction of the cosmic energy density can be transferred to the longitudinal gravitino due to non-trivial change of its sound speed. This implies either a breakdown of the effective theory after inflation or a serious gravitino problem.
Origin of density fluctuations in extended inflation
International Nuclear Information System (INIS)
Kolb, E.W.; Salopek, D.S.; Turner, M.S.
1990-01-01
We calculate both the curvature and isocurvature density fluctuations that arise due to quantum fluctuations in a simple model of extended inflation based upon the Jordan-Brans-Dicke theory. The curvature fluctuations that arise due to quantum fluctuations in the Brans-Dicke field in general have a non-scale-invariant spectrum and an amplitude that is cosmologically acceptable and interesting without having to tune any coupling constant to a very small value. The curvature perturbations that arise due to the Higgs field are subdominant. If there are other massless fields in the theory, e.g., an axion or an ilion, then isocurvature fluctuations arise in these fields too. Production of gravitational waves and the massless particles associated with excitations of the Brans-Dicke field are also discussed. Several attempts at more realistic models of extended inflation are also analyzed. The importance of the Einstein conformal frame in calculating curvature fluctuations is emphasized. When viewed in this frame, extended inflation closely resembles slow-rollover inflation with an exponential potential, and the usual formula for the amplitude of curvature perturbations applies directly
Unitarity and predictiveness in new Higgs inflation
Fumagalli, Jacopo; Mooij, Sander; Postma, Marieke
2018-03-01
In new Higgs inflation the Higgs kinetic terms are non-minimally coupled to the Einstein tensor, allowing the Higgs field to play the role of the inflaton. The new interaction is non-renormalizable, and the model only describes physics below some cutoff scale. Even if the unknown UV physics does not affect the tree level inflaton potential significantly, it may still enter at loop level and modify the running of the Standard Model (SM) parameters. This is analogous to what happens in the original model for Higgs inflation. A key difference, though, is that in new Higgs inflation the inflationary predictions are sensitive to this running. Thus the boundary conditions at the EW scale as well as the unknown UV completion may leave a signature on the inflationary parameters. However, this dependence can be evaded if the kinetic terms of the SM fermions and gauge fields are non-minimally coupled to gravity as well. Our approach to determine the model's UV dependence and the connection between low and high scale physics can be used in any particle physics model of inflation.
Consistency relation in power law G-inflation
International Nuclear Information System (INIS)
Unnikrishnan, Sanil; Shankaranarayanan, S.
2014-01-01
In the standard inflationary scenario based on a minimally coupled scalar field, canonical or non-canonical, the subluminal propagation of speed of scalar perturbations ensures the following consistency relation: r ≤ −8n T , where r is the tensor-to-scalar-ratio and n T is the spectral index for tensor perturbations. However, recently, it has been demonstrated that this consistency relation could be violated in Galilean inflation models even in the absence of superluminal propagation of scalar perturbations. It is therefore interesting to investigate whether the subluminal propagation of scalar field perturbations impose any bound on the ratio r/|n T | in G-inflation models. In this paper, we derive the consistency relation for a class of G-inflation models that lead to power law inflation. Within these class of models, it turns out that one can have r > −8n T or r ≤ −8n T depending on the model parameters. However, the subluminal propagation of speed of scalar field perturbations, as required by causality, restricts r ≤ −(32/3) n T
33 CFR 150.507 - How must the operator service inflatable lifesaving appliances?
2010-07-01
... inflatable lifesaving appliances? 150.507 Section 150.507 Navigation and Navigable Waters COAST GUARD... Specialty Equipment Inflatable Lifesaving Appliances § 150.507 How must the operator service inflatable lifesaving appliances? (a) The operator must service each inflatable liferaft according to 46 CFR subpart 160...
On the One Loop Corrections to Inflation II
DEFF Research Database (Denmark)
Sloth, Martin Snoager
2006-01-01
In this paper we extend our previous treatment of the one-loop corrections to inflation. Previously we calculated the one-loop corrections to the background and the two-point correlation function of inflaton fluctuations in a specific model of chaotic inflation. We showed that the loop correction...... model of chaotic inflation with a quadratic inflationary potential. We discuss the physical interpretation of the effect in terms of the tensor-to-scalar consistency relation. Finally, we discuss the relation to the work of Weinberg on quantum contributions to cosmological correlators....
Document of the Month: A Poster on Inflation.
Smith, Nadine; Walker, Samuel J.
1979-01-01
Presents an inflation poster as an example of the Office of Price Administration's (OPA) campaign to convince American people to control inflation during World War II. Suggestions for teaching and discussion questions based on the poster are included. (KC)
Explosive dome eruptions modulated by periodic gas-driven inflation
Johnson, Jeffrey B.; Lyons, John; Andrews, B. J.; Lees, J.M.
2014-01-01
Volcan Santiaguito (Guatemala) “breathes” with extraordinary regularity as the edifice's conduit system accumulates free gas, which periodically vents to the atmosphere. Periodic pressurization controls explosion timing, which nearly always occurs at peak inflation, as detected with tiltmeters. Tilt cycles in January 2012 reveal regular 26 ± 6 min inflation/deflation cycles corresponding to at least ~101 kg/s of gas fluxing the system. Very long period (VLP) earthquakes presage explosions and occur during cycles when inflation rates are most rapid. VLPs locate ~300 m below the vent and indicate mobilization of volatiles, which ascend at ~50 m/s. Rapid gas ascent feeds pyroclast-laden eruptions lasting several minutes and rising to ~1 km. VLPs are not observed during less rapid inflation episodes; instead, gas vents passively through the conduit producing no infrasound and no explosion. These observations intimate that steady gas exsolution and accumulation in shallow reservoirs may drive inflation cycles at open-vent silicic volcanoes.
Pati-Salam version of subcritical hybrid inflation
Bryant, B. Charles; Raby, Stuart
2016-05-01
In this paper we present a model of subcritical hybrid inflation with a Pati-Salam (PS) symmetry group. Both the inflaton and waterfall fields contribute to the necessary e -foldings of inflation, while only the waterfall field spontaneously breaks PS hence monopoles produced during inflation are diluted during the inflationary epoch. The model is able to produce a tensor-to-scalar ratio, r model also incorporates a Z4R symmetry which can resolve the μ problem and suppress dimension 5 operators for proton decay, leaving over an exact R parity. Finally the model allows for a complete three-family extension with a D4 family symmetry which reproduces low energy precision electroweak and LHC data.
Inflation and Instability of a Polymeric Membrane
DEFF Research Database (Denmark)
Hassager, Ole; Kristensen, Susanne Brogaard; Larsen, Johannes Ruben
1999-01-01
We consider an axisymmetric polymeric membrane inflated by a uniform pressure difference acting across the membrane. The polymeric material is described by an arbitrary combination of a viscoelastic and a purely viscous component to the stress. Some viscoelastic materials described by a Mooney......-Rivlin model show a monotone increasing pressure during inflation of a spherical membrane. These materials develop a homogeneous membrane thickness in agreement with the Considere-Pearson condition. Molecularly based models such as the neo-Hookean, Doi-Edwards or Tom-Pom model show a pressure maximum when...... inflated. Membranes described by these models develop a local thinning of the membrane which may lead to bursting in finite time. (C) 1999 Elsevier Science B.V. All rights reserved....
Cosmological perturbations in the new Higgs inflation
Energy Technology Data Exchange (ETDEWEB)
Germani, Cristiano [Arnold Sommerfeld Center, Ludwig-Maximilians-University, Theresienstr, 37 80333 Muenchen (Germany); Kehagias, Alex, E-mail: cristiano.germani@lmu.de, E-mail: kehagias@central.ntua.gr [Physics Division, National Technical University of Athens, 15780 Zografou Campus, Athens (Greece)
2010-05-01
We study the cosmological perturbations created during the New Higgs inflationary phase. In the New Higgs Inflation, the Higgs boson is kinetically coupled to the Einstein tensor and only three perturbative degrees of freedom, a scalar and two tensorial (gravitational waves), propagate during Inflation. Scalar perturbations are found to match the latest WMAP-7yrs data within Standard Model Higgs parameters. Primordial gravitational waves also, although propagating with superluminal speed, are consistent with present data. Finally, we estimate the values of the parameter of the New Higgs Inflation in relation to the Higgs mass, the spectral index and amplitude of the primordial scalar perturbations showing that the unitarity bound of the theory is not violated.
The problem with false vacuum Higgs inflation
International Nuclear Information System (INIS)
Fairbairn, Malcolm; Grothaus, Philipp; Hogan, Robert
2014-01-01
We investigate the possibility of using the only known fundamental scalar, the Higgs, as an inflaton with minimal coupling to gravity. The peculiar appearance of a plateau or a false vacuum in the renormalised effective scalar potential suggests that the Higgs might drive inflation. For the case of a false vacuum we use an additional singlet scalar field, motivated by the strong CP problem, and its coupling to the Higgs to lift the barrier allowing for a graceful exit from inflation by mimicking hybrid inflation. We find that this scenario is incompatible with current measurements of the Higgs mass and the QCD coupling constant and conclude that the Higgs can only be the inflaton in more complicated scenarios
Deflation of the cosmological constant associated with inflation and dark energy
International Nuclear Information System (INIS)
Geng, Chao-Qiang; Lee, Chung-Chi
2016-01-01
In order to solve the fine-tuning problem of the cosmological constant, we propose a simple model with the vacuum energy non-minimally coupled to the inflaton field. In this model, the vacuum energy decays to the inflaton during pre-inflation and inflation eras, so that the cosmological constant effectively deflates from the Planck mass scale to a much smaller one after inflation and plays the role of dark energy in the late-time of the universe. We show that our deflationary scenario is applicable to arbitrary slow-roll inflation models. We also take two specific inflation potentials to illustrate our results.
Reheating for closed string inflation
Energy Technology Data Exchange (ETDEWEB)
Cicoli, Michele [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Mazumdar, Anupam [Lancaster Univ. (United Kingdom). Physics Dept.; Copenhagen Univ. (Denmark). Niels Bohr Institute
2010-05-15
We point out some of the outstanding challenges for embedding inflationary cosmology within string theory studying the process of reheating for models where the inflaton is a closed string mode parameterising the size of an internal cycle of the compactification manifold. A realistic model of inflation must explain the tiny perturbations in the cosmic microwave background radiation and also how to excite the ordinary matter degrees of freedom after inflation, required for the success of Big Bang Nucleosynthesis. We study these issues focusing on two promising inflationary models embedded in LARGE volume type IIB flux compactifications. We show that phenomenological requirements and consistency of the effective field theory treatment imply the presence at low energies of a hidden sector together with a visible sector, where the Minimal Supersymmetric Standard Model fields are residing. A detailed calculation of the inflaton coupling to the fields of the hidden sector, visible sector, and moduli sector, reveals that the inflaton fails to excite primarily the visible sector fields, instead hidden sector fields are excited copiously after the end of inflation. This sets severe constraints on hidden sector model building where the most promising scenario emerges as a pure N=1 SYM theory, forbidding the kinematical decay of the inflaton to the hidden sector. In this case it is possible to reheat the Universe with the visible degrees of freedom even though in some cases we discover a new tension between TeV scale SUSY and reheating on top of the well-known tension between TeV scale SUSY and inflation. (orig.)
Reheating for closed string inflation
International Nuclear Information System (INIS)
Cicoli, Michele; Mazumdar, Anupam; Copenhagen Univ.
2010-05-01
We point out some of the outstanding challenges for embedding inflationary cosmology within string theory studying the process of reheating for models where the inflaton is a closed string mode parameterising the size of an internal cycle of the compactification manifold. A realistic model of inflation must explain the tiny perturbations in the cosmic microwave background radiation and also how to excite the ordinary matter degrees of freedom after inflation, required for the success of Big Bang Nucleosynthesis. We study these issues focusing on two promising inflationary models embedded in LARGE volume type IIB flux compactifications. We show that phenomenological requirements and consistency of the effective field theory treatment imply the presence at low energies of a hidden sector together with a visible sector, where the Minimal Supersymmetric Standard Model fields are residing. A detailed calculation of the inflaton coupling to the fields of the hidden sector, visible sector, and moduli sector, reveals that the inflaton fails to excite primarily the visible sector fields, instead hidden sector fields are excited copiously after the end of inflation. This sets severe constraints on hidden sector model building where the most promising scenario emerges as a pure N=1 SYM theory, forbidding the kinematical decay of the inflaton to the hidden sector. In this case it is possible to reheat the Universe with the visible degrees of freedom even though in some cases we discover a new tension between TeV scale SUSY and reheating on top of the well-known tension between TeV scale SUSY and inflation. (orig.)
A Non-linear "Inflation-Relative Prices Variability" Relationship: Evidence from Latin America
Mª Ángeles Caraballo Pou; Carlos Dabús; Diego Caramuta
2006-01-01
This paper presents evidence on a non-linear "inflation-relative prices variability" relationship in three Latin American countries with very high inflation experiences: Argentina, Brazil and Peru. More precisely, and in contrast to results found in previous literature for similar countries, we find a non-concave relation at higher inflation regimes, i.e. when inflation rate surpasses certain threshold. This non-concavity is mainly explained by the unexpected component of inflation, which sug...
Quintessential inflation on the brane and the relic gravity wave background
International Nuclear Information System (INIS)
Sami, M.; Sahni, V.
2004-01-01
Quintessential inflation describes a scenario in which both inflation and dark energy (quintessence) are described by the same scalar field. In conventional braneworld models of quintessential inflation gravitational particle-production is used to reheat the universe. This reheating mechanism is very inefficient and results in an excessive production of gravity waves which violate nucleosynthesis constraints and invalidate the model. We describe a new method of realizing quintessential inflation on the brane in which inflation is followed by 'instant preheating' (Felder, Kofman and Linde 1999). The larger reheating temperature in this model results in a smaller amplitude of relic gravity waves which is consistent with nucleosynthesis bounds. The relic gravity wave background has a 'blue' spectrum at high frequencies and is a generic byproduct of successful quintessential inflation on the brane
Particle physics models of inflation in supergravity and grand unification
International Nuclear Information System (INIS)
Kostka, Philipp Manuel
2010-01-01
In the first part of this thesis, we study classes of hybrid and chaotic inflation models in four-dimensional N=1 supergravity. Therein, the η-problem can be resolved relying on fundamental symmetries in the Kaehler potential. Concretely, we investigate explicit realizations of superpotentials, in which the flatness of the inflaton potential is protected at tree level by a shift symmetry or a Heisenberg symmetry in the Kaehler potential. In the latter case, the associated modulus field can be stabilized during inflation by supergravity effects. In the context of hybrid inflation, a novel class of models, to which we refer as ''tribrid inflation,'' turns out to be particularly compatible with such symmetry solutions to the η-problem. Radiative corrections due to operators in the superpotential, which break the respective symmetry, generate the required small slope of the inflaton potential. Additional effective operators in the Kaehler potential can reduce the predicted spectral index so that it agrees with latest observational data. Within a model of chaotic inflation in supergravity with a quadratic potential, we apply the Heisenberg symmetry to allow for viable inflation with super-Planckian field values, while the associated modulus is stabilized. We show that radiative corrections are negligible in this context. In the second part, the tribrid inflation models are extended to realize gauge non-singlet inflation. This is applied to the matter sector of supersymmetric Grand Unified Theories based on the Pati-Salam gauge group. For the specific scenario in which the right-handed sneutrino is the inflaton, we study the scalar potential in a D-flat valley. We show that despite potentially dangerous two-loop corrections, the required flatness of the potential can be maintained. The reason for this is the strong suppression of gauge interactions of the inflaton field due to its symmetry breaking vacuum expectation value. In addition, the production of stable
Particle physics models of inflation in supergravity and grand unification
Energy Technology Data Exchange (ETDEWEB)
Kostka, Philipp Manuel
2010-12-03
In the first part of this thesis, we study classes of hybrid and chaotic inflation models in four-dimensional N=1 supergravity. Therein, the {eta}-problem can be resolved relying on fundamental symmetries in the Kaehler potential. Concretely, we investigate explicit realizations of superpotentials, in which the flatness of the inflaton potential is protected at tree level by a shift symmetry or a Heisenberg symmetry in the Kaehler potential. In the latter case, the associated modulus field can be stabilized during inflation by supergravity effects. In the context of hybrid inflation, a novel class of models, to which we refer as ''tribrid inflation,'' turns out to be particularly compatible with such symmetry solutions to the {eta}-problem. Radiative corrections due to operators in the superpotential, which break the respective symmetry, generate the required small slope of the inflaton potential. Additional effective operators in the Kaehler potential can reduce the predicted spectral index so that it agrees with latest observational data. Within a model of chaotic inflation in supergravity with a quadratic potential, we apply the Heisenberg symmetry to allow for viable inflation with super-Planckian field values, while the associated modulus is stabilized. We show that radiative corrections are negligible in this context. In the second part, the tribrid inflation models are extended to realize gauge non-singlet inflation. This is applied to the matter sector of supersymmetric Grand Unified Theories based on the Pati-Salam gauge group. For the specific scenario in which the right-handed sneutrino is the inflaton, we study the scalar potential in a D-flat valley. We show that despite potentially dangerous two-loop corrections, the required flatness of the potential can be maintained. The reason for this is the strong suppression of gauge interactions of the inflaton field due to its symmetry breaking vacuum expectation value. In addition, the
The Effects of Remittances on Inflation: Evidence from Bangladesh
Directory of Open Access Journals (Sweden)
Z. S. Khan
2013-12-01
Full Text Available Like many developing countries, remittances are relatively larger capital inflows in Bangladesh in the recent years. Hence, understanding the impact of remittances on the macroeconomic variables such as inflation is essential for the policy makers of the recipient economy. Incorporating remittances as an exogenous variable to the standard inflation function, this paper verifies how it affects the inflation rate in Bangladesh in the 1972-2010 periods. Applying Vector Autoregressive (VAR techniques, the empirical results find that a one percent increase in remittances inflows increases inflation rate by 2.48 percent in the long run, whereas no significant relationship is evident between these two variables in the short-run in Bangladesh.
Zero-inflated Conway-Maxwell Poisson Distribution to Analyze Discrete Data.
Sim, Shin Zhu; Gupta, Ramesh C; Ong, Seng Huat
2018-01-09
In this paper, we study the zero-inflated Conway-Maxwell Poisson (ZICMP) distribution and develop a regression model. Score and likelihood ratio tests are also implemented for testing the inflation/deflation parameter. Simulation studies are carried out to examine the performance of these tests. A data example is presented to illustrate the concepts. In this example, the proposed model is compared to the well-known zero-inflated Poisson (ZIP) and the zero- inflated generalized Poisson (ZIGP) regression models. It is shown that the fit by ZICMP is comparable or better than these models.
Higgsed Chromo-Natural Inflation
Energy Technology Data Exchange (ETDEWEB)
Adshead, Peter [Department of Physics, University of Illinois at Urbana-Champaign,1110 West Green Street, Urbana, IL 61801 (United States); Martinec, Emil [Enrico Fermi Institute, University of Chicago,5640 S. Ellis Ave., Chicago, IL 60637-1433 (United States); Department of Physics, University of Chicago,5640 S. Ellis Ave., Chicago, IL 60637-1433 (United States); Sfakianakis, Evangelos I. [Department of Physics, University of Illinois at Urbana-Champaign,1110 West Green Street, Urbana, IL 61801 (United States); Wyman, Mark [PDT Partners,1745 Broadway, 25th Floor, New York, NY 10019 (United States)
2016-12-27
We demonstrate that Chromo-Natural Inflation can be made consistent with observational data if the SU(2) gauge symmetry is spontaneously broken. Working in the Stueckelberg limit, we show that isocurvature is negligible, and the resulting adiabatic fluctuations can match current observational constraints. Observable levels of chirally-polarized gravitational radiation (r∼10{sup −3}) can be produced while the evolution of all background fields is sub-Planckian. The gravitational wave spectrum is amplified via linear mixing with the gauge field fluctuations, and its amplitude is not simply set by the Hubble rate during inflation. This allows observable gravitational waves to be produced for an inflationary energy scale below the GUT scale. The tilt of the resulting gravitational wave spectrum can be either blue or red.
Higgsed Chromo-Natural Inflation
International Nuclear Information System (INIS)
Adshead, Peter; Martinec, Emil; Sfakianakis, Evangelos I.; Wyman, Mark
2016-01-01
We demonstrate that Chromo-Natural Inflation can be made consistent with observational data if the SU(2) gauge symmetry is spontaneously broken. Working in the Stueckelberg limit, we show that isocurvature is negligible, and the resulting adiabatic fluctuations can match current observational constraints. Observable levels of chirally-polarized gravitational radiation (r∼10 −3 ) can be produced while the evolution of all background fields is sub-Planckian. The gravitational wave spectrum is amplified via linear mixing with the gauge field fluctuations, and its amplitude is not simply set by the Hubble rate during inflation. This allows observable gravitational waves to be produced for an inflationary energy scale below the GUT scale. The tilt of the resulting gravitational wave spectrum can be either blue or red.
Effects of user experience and method in the inflation of ...
African Journals Online (AJOL)
Context: Endotracheal tube cuff pressure (ETCP) is recommended to be maintained between 20.30 cmH2O limits. While insufficient inflation of ETC may cause aspirations, over.inflation of it may lead to damage in tracheal epithelium. Aims: We planned to investigate the effects of user experience and cuff pressure inflation ...
76 FR 74720 - Inflation Adjustment of Civil Monetary Penalties; Correction
2011-12-01
... FEDERAL MARITIME COMMISSION 46 CFR Part 506 [Docket No. 09-04] RIN 3072-AC36 Inflation Adjustment... published in the Federal Register of Friday, July 31, 2009 (74 FR 38114). The rule adjusts for inflation the... accordance with the requirements of the Federal Civil Penalties Inflation Adjustment Act of 1990, as amended...
Dynamical Baryogenesis in Complex Hybrid Inflation
International Nuclear Information System (INIS)
Delepine, David; Martinez, Carlos; Urena-Lopez, L. Arturo
2008-01-01
We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U (1) global symmetry associated to the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vev of the waterfall field, which is well constrained by diverse cosmological observations
Inflation Hedging for Long-Term Investors
Shaun K. Roache; Alexander P. Attie
2009-01-01
Long-term investors face a common problem-how to maintain the purchasing power of their assets over time and achieve a level of real returns consistent with their investment objectives. While inflation-linked bonds and derivatives have been developed to hedge the effects of inflation, their limited supply and liquidity lead many investors to continue to rely on the indirect hedging properties of traditional asset classes. In this paper, we assess these properties over different time horizons,...
Inflation is Always and Everywhere an Interest-Rate Phenomenon
Belanger, Gilles
2016-01-01
Following an earlier paper, I investigate an economy where nominal interest rates are rigid, but aggregate prices are not. Though the title exaggerates, interest rates rigidity does account for an uncanny number of stylized facts about inflation. This paper shows that previously shown results are robust to changes in the specification of interest rate rigidity. Results investigated include: (1) the procyclicality of inflation, (2) inflation control through interest rate manipulation,(3) the ...
Is inflation from unwinding fluxes IIB?
Energy Technology Data Exchange (ETDEWEB)
Gautason, Fridrik Freyr [Instituut voor Theoretische Fysica, K.University Leuven,Celestijnenlaan 200D, B-3001 Leuven (Belgium); Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS,Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Schillo, Marjorie; Riet, Thomas Van [Instituut voor Theoretische Fysica, K.University Leuven,Celestijnenlaan 200D, B-3001 Leuven (Belgium)
2017-03-07
In this paper we argue that the mechanism of unwinding inflation is naturally present in warped compactifications of type IIB string theory with local throats. The unwinding of flux is caused by its annihilation against branes. The resulting inflaton potential is linear with periodic modulations. We initiate an analysis of the inflationary dynamics and cosmological observables, which are highly constrained by moduli stabilization. For the simplified model of single-Kähler Calabi-Yau spaces we find that many, though not all of the consistency constraints can be satisfied. Particularly, in this simple model geometric constraints are in tension with obtaining the observed amplitude of the scalar power spectrum. However, we do find 60 efolds of inflation with a trans-Planckian field excursion which offers the hope that slightly more complicated models can lead to a fully consistent explicit construction of large field inflation of this kind.
Lowering Regional Inflation? Improve Budget Absorption
Directory of Open Access Journals (Sweden)
Vid Adrison
2016-08-01
Full Text Available The subnational government spending in Indonesia exhibit a highly skewed distribution, i.e., it is very low in the first two-quarters and then increases significantly in the last two-quarters. Such explosive pattern poses two disadvantages. First, the regional output will fall below its optimal level as the low government capital expenditure leads to a fewer provision of public goods. Second, a significant increase in government spending in the later quarter pushes the short run aggregate demand to the northeast and creates an inflationary pressure in the following quarters. In this study, we analyze the effect of quarterly regional government expenditure growth on regional inflation during 2010–2014. Using Arellano Bond GMM estimation, we find government expenditure growth leads to higher inflation in the same quarter. A percentage increase in non-capital expenditure spending results in a higher inflation than a percentage increase in capital spending.
Ross, Graham G.; Germán, Gabriel; Vázquez, J. Alberto
2016-05-01
We construct two simple effective field theory versions of Hybrid Natural Inflation (HNI) that illustrate the range of its phenomenological implications. The resulting inflationary sector potential, V = Δ4(1 + acos( ϕ/f)), arises naturally, with the inflaton field a pseudo-Nambu-Goldstone boson. The end of inflation is triggered by a waterfall field and the conditions for this to happen are determined. Also of interest is the fact that the slow-roll parameter ɛ (and hence the tensor r) is a non-monotonic function of the field with a maximum where observables take universal values that determines the maximum possible tensor to scalar ratio r. In one of the models the inflationary scale can be as low as the electroweak scale. We explore in detail the associated HNI phenomenology, taking account of the constraints from Black Hole production, and perform a detailed fit to the Planck 2015 temperature and polarisation data.
International Nuclear Information System (INIS)
Ross, Graham G.; Germán, Gabriel; Vázquez, J. Alberto
2016-01-01
We construct two simple effective field theory versions of Hybrid Natural Inflation (HNI) that illustrate the range of its phenomenological implications. The resulting inflationary sector potential, V=Δ"4(1+acos (ϕ/f)), arises naturally, with the inflaton field a pseudo-Nambu-Goldstone boson. The end of inflation is triggered by a waterfall field and the conditions for this to happen are determined. Also of interest is the fact that the slow-roll parameter ϵ (and hence the tensor r) is a non-monotonic function of the field with a maximum where observables take universal values that determines the maximum possible tensor to scalar ratio r. In one of the models the inflationary scale can be as low as the electroweak scale. We explore in detail the associated HNI phenomenology, taking account of the constraints from Black Hole production, and perform a detailed fit to the Planck 2015 temperature and polarisation data.
International Nuclear Information System (INIS)
Mishra, Hiranmaya; Mohanty, Subhendra; Nautiyal, Akhilesh
2012-01-01
In warm inflation models there is the requirement of generating large dissipative couplings of the inflaton with radiation, while at the same time, not de-stabilising the flatness of the inflaton potential due to radiative corrections. One way to achieve this without fine tuning unrelated couplings is by supersymmetry. In this Letter we show that if the inflaton and other light fields are pseudo-Nambu-Goldstone bosons then the radiative corrections to the potential are suppressed and the thermal corrections are small as long as the temperature is below the symmetry breaking scale. In such models it is possible to fulfil the contrary requirements of an inflaton potential which is stable under radiative corrections and the generation of a large dissipative coupling of the inflaton field with other light fields. We construct a warm inflation model which gives the observed CMB-anisotropy amplitude and spectral index where the symmetry breaking is at the GUT scale.
Large non-Gaussianity from two-component hybrid inflation
International Nuclear Information System (INIS)
Byrnes, Christian T.; Choi, Ki-Young; Hall, Lisa M.H.
2009-01-01
We study the generation of non-Gaussianity in models of hybrid inflation with two inflaton fields, (2-brid inflation). We analyse the region in the parameter and the initial condition space where a large non-Gaussianity may be generated during slow-roll inflation which is generally characterised by a large f NL , τ NL and a small g NL . For certain parameter values we can satisfy τ NL >> f NL 2 . The bispectrum is of the local type but may have a significant scale dependence. We show that the loop corrections to the power spectrum and bispectrum are suppressed during inflation, if one assume that the fields follow a classical background trajectory. We also include the effect of the waterfall field, which can lead to a significant change in the observables after the waterfall field is destabilised, depending on the couplings between the waterfall and inflaton fields
Higher order corrections to asymptotic-de Sitter inflation
Mohsenzadeh, M.; Yusofi, E.
2017-08-01
Since trans-Planckian considerations can be associated with the re-definition of the initial vacuum, we investigate further the influence of trans-Planckian physics on the spectra produced by the initial quasi-de Sitter (dS) state during inflation. We use the asymptotic-dS mode to study the trans-Planckian correction of the power spectrum to the quasi-dS inflation. The obtained spectra consist of higher order corrections associated with the type of geometry and harmonic terms sensitive to the fluctuations of space-time (or gravitational waves) during inflation. As an important result, the amplitude of the power spectrum is dependent on the choice of c, i.e. the type of space-time in the period of inflation. Also, the results are always valid for any asymptotic dS space-time and particularly coincide with the conventional results for dS and flat space-time.