Parity asymmetric boost invariant plasma in AdS/CFT correspondence
We consider a simple extension to the previously found gravity solution corresponding to a boost invariant Bjorken plasma, by allowing components that are asymmetric under parity flipping of the spacetime rapidity. Besides the question whether this may have a realization in collisions of different species of projectiles, such as lead-gold collision, our new time-dependent gravity background can serve as a test ground for the recently proposed second order conformal viscous hydrodynamics. We find that non-trivial parity-asymmetric effects start to appear at second order in late time expansion, and we map the corresponding energy-momentum tensor to the second order conformal hydrodynamics to find certain second order transport coefficients. Our results are in agreement with the previous results in literature, giving one more corroborative evidence for the validity of the framework. (author)
Complexified boost invariance and holographic heavy ion collisions
Gubser, Steven; van der Schee, Wilke
2014-01-01
At strong coupling holographic studies have shown that heavy ion collisions do not obey normal boost invariance. Here we study a modified boost invariance through a complex shift in time, and show that this leads to surprisingly good agreement with numerical holographic computations. When including perturbations the agreement becomes even better, both in the hydrodynamic and the far-from-equilibrium regime. One of the main advantages is an analytic formulation of the stress-energy tensor of t...
Complexified boost invariance and holographic heavy ion collisions
Gubser, Steven S
2015-01-01
At strong coupling holographic studies have shown that heavy ion collisions do not obey normal boost invariance. Here we study a modified boost invariance through a complex shift in time, and show that this leads to surprisingly good agreement with numerical holographic computations. When including perturbations the agreement becomes even better, both in the hydrodynamic and the far-from-equilibrium regime. One of the main advantages is an analytic formulation of the stress-energy tensor of the longitudinal dynamics of holographic heavy ion collisions.
Black brane entropy and hydrodynamics: The boost-invariant case
The framework of slowly evolving horizons is generalized to the case of black branes in asymptotically anti-de Sitter spaces in arbitrary dimensions. The results are used to analyze the behavior of both event and apparent horizons in the gravity dual to boost-invariant flow. These considerations are motivated by the fact that at second order in the gradient expansion the hydrodynamic entropy current in the dual Yang-Mills theory appears to contain an ambiguity. This ambiguity, in the case of boost-invariant flow, is linked with a similar freedom on the gravity side. This leads to a phenomenological definition of the entropy of black branes. Some insights on fluid/gravity duality and the definition of entropy in a time-dependent setting are elucidated.
Area Invariance of Apparent Horizons under Arbitrary Boosts
Akcay, Sarp
2007-01-01
It is a well known analytic result in general relativity that the 2-dimensional area of the horizon of a black hole remains invariant regardless of the motion of the observer, and in fact is independent of the $ t=constant $ slice, which can be quite arbitrary in general relativity. Nonetheless the explicit computation of horizon area is often substantially more difficult in some frames (complicated by the coordinate form of the metric), than in other frames. Here we give an explicit demonstration for very restricted metric forms of (Schwarzschild and Kerr) vacuum black holes. In the Kerr-Schild coordinate expression for these spacetimes they have an explicit Lorentz-invariant form. We consider {\\it boosted} versions with the black hole moving through the coordinate system. Since these are stationary black hole spacetimes, the apparent horizons are 2D crosssections of their event horizons, so we compute the areas of apparent horizons in the boosted space with (boosted) $ t = constant $, and obtain the same re...
Black brane entropy and hydrodynamics: the boost-invariant case
Booth, Ivan; Heller, Michal P.; Spalinski, Michal
2009-01-01
The framework of slowly evolving horizons is generalized to the case of black branes in asymptotically anti-de Sitter spaces in arbitrary dimensions. The results are used to analyze the behavior of both event and apparent horizons in the gravity dual to boost-invariant flow. These considerations are motivated by the fact that at second order in the gradient expansion the hydrodynamic entropy current in the dual Yang-Mills theory appears to contain an ambiguity. This ambiguity, in the case of ...
Modifications to Lorentz invariant dispersion in relatively boosted frames
We investigate the implications of energy dependence of the speed of photons, one of the candidate effects of quantum-gravity theories that has been most studied recently, from the perspective of observations in different reference frames. We examine how a simultaneous burst of photons would be measured by two observers with a relative velocity, establishing some associated conditions for the consistency of theories. For scenarios where the Lorentz transformations remain valid, these consistency conditions allow us to characterize the violations of Lorentz symmetry through an explicit description of the modification of the quantum-gravity scale in boosted frames with respect to its definition in a preferred frame. When applied to relativistic scenarios with a deformation of Lorentz invariance that preserves the equivalence of inertial observers, we find an insightful characterization of the necessity to adopt in such frameworks nonclassical features of spacetime geometry, e.g. events that are at the same spacetime point for one observer cannot be considered at the same spacetime point for other observers. Our findings also suggest that, at least in principle (and perhaps one day even in practice), measurements of the dispersion of photons in relatively boosted frames can be particularly valuable for the purpose of testing these scenarios.
Boost invariant quantum evolution of a meson field at large proper times
Asymptotic solutions of the functional Schroedinger equation are constructed for a scalar field in the Gaussian approximation at large proper time. These solutions describe the late proper time stages of the expansion of a meson gas with boost invariant boundary conditions. The relevance of these solutions for the formation of a disoriented chiral condensate in ultra relativistic collisions is discussed. (author)
A non-boost-invariant solution of relativistic hydrodynamics in 1+3 dimensions
Hatta, Yoshitaka; Yang, Di-Lun
2015-01-01
We present a new solution of relativistic hydrodynamics in 1+3 dimensions which depends on both the transverse coordinate and rapidity. At early times the flow expands dominantly longitudinally in a non-boost-invariant manner, and at late times it expands nearly spherically. These two regimes are shown to be related by symmetry. The effect of viscosity is also discussed.
Holographic dual of a boost-invariant plasma with chemical potential
We construct a gravity dual of a boost-invariant flow of an N=4 SU(N) supersymmetric Yang-Mills gauge theory plasma with chemical potential. We present both a first-order corrected late-time solution in Eddington-Finkelstein coordinates and a zeroth-order solution in parametric form in Fefferman-Graham coordinates. The resulting background takes the form of a time-dependent AdS Reissner-Nordstroem-type black hole whose horizons move into the bulk of the AdS space. The solution correctly reproduces the energy and charge density as well as the viscosity of the plasma previously computed in the literature. (orig.)
Holographic dual of a boost-invariant plasma with chemical potential
Kalaydzhyan, Tigran; Kirsch, Ingo
2010-12-15
We construct a gravity dual of a boost-invariant flow of an N=4 SU(N) supersymmetric Yang-Mills gauge theory plasma with chemical potential. We present both a first-order corrected late-time solution in Eddington-Finkelstein coordinates and a zeroth-order solution in parametric form in Fefferman-Graham coordinates. The resulting background takes the form of a time-dependent AdS Reissner-Nordstroem-type black hole whose horizons move into the bulk of the AdS space. The solution correctly reproduces the energy and charge density as well as the viscosity of the plasma previously computed in the literature. (orig.)
Evolution of non-local observables in an expanding boost-invariant plasma
Pedraza, Juan F
2014-01-01
Using the AdS/CFT correspondence, we compute analytically the late-time behavior of two-point functions, Wilson loops and entanglement entropy in a strongly-coupled $\\mathcal{N}=4$ super-Yang-Mills plasma undergoing a boost-invariant expansion. We take into account the effects of first order dissipative hydrodynamics and investigate the effects of the (time dependent) shear viscosity on the various observables. The two-point functions decay exponentially at late times and are unaffected by the viscosity if the points are separated along the transverse directions. For longitudinal separation we find a much richer structure. In this case the exponential is modulated by a non-monotonic function of the rapidities and a dimensionless combination of the shear viscosity and proper time. Similar results are found for certain Wilson loops and entanglement entropies.
Using gauge/gravity duality, we study the creation and evolution of boost-invariant anisotropic, strongly-coupled N=4 supersymmetric Yang-Mills plasma. In the dual gravitational description, this corresponds to horizon formation in a geometry driven to be anisotropic by a time-dependent change in boundary conditions.
Thermalization of a boost-invariant non-Abelian plasma: Holographic approach with boundary sourcing
Bellantuono, Loredana; De Fazio, Fulvia; Giannuzzi, Floriana
2015-01-01
In a holographic approach, the evolution of a 4D strongly coupled non-Abelian plasma towards equilibrium can be studied investigating a 5D gravitational dual. The process driving the plasma out-of-equilibrium can be described by boundary sourcing, a deformation of the boundary metric; the analysis of the late-time dynamics allows to understand how the hydrodynamic regime settles in. We apply the method to a boost-invariant case, considering the effects of different quenches, solving the Einstein equations in the bulk and studying the time-dependence of observables such as the effective temperature, the energy density and the pressures. The main outcome is that, if the effective temperature of the system when the quench is switched off is $T_{eff}(\\tau^*)=500$ MeV, thermalization is reached within a time of ${\\cal O}$(1 fm/c), an important information if the case of the QCD plasma produced in relativistic heavy ion collisions is considered.
Choudhury, A.G.; Chowdhury, A.R. [Jadavpur Univ., Calcutta (India)
1996-08-01
Intertwining relations for the quantum R-matrix of the SU{sub p,q}(2) invariant spin chain are obtained and the corresponding face model is deduced. An important difference is seen to arise due to the asymmetry generated by the parameters p and q, which leads to a asymmetric face model. An algebraic Bethe ansatz is set up and solved with the help of these intertwining vectors.
Tobar, M E; McFerran, J J; Guéna, J; Abgrall, M; Bize, S; Clairon, A; Laurent, Ph; Rosenbusch, P; Rovera, D; Santarelli, G
2013-01-01
The frequencies of three separate Cs fountain clocks and one Rb fountain clock have been compared to various hydrogen masers to search for periodic changes correlated with the changing solar gravitational potential at the Earth and boost with respect to the Cosmic Microwave Background (CMB) rest frame. The data sets span over more than eight years. The main sources of long-term noise in such experiments are the offsets and linear drifts associated with the various H-masers. The drift can vary from nearly immeasurable to as high as 1.3*10^-15 per day. To circumvent these effects we apply a numerical derivative to the data, which significantly reduces the standard error when searching for periodic signals. We determine a standard error for the putative Local Position Invariance (LPI) coefficient with respect to gravity for a Cs-Fountain H-maser comparison of 4.8*10^-6 and 10^-5 for a Rb-Fountain H-maser comparison. From the same data the putative boost LPI coefficients were measured to a precision of up to part...
Mo, W.; Loh, Poh Chiang; Blaabjerg, Frede
Z-source Neutral Point Clamped (NPC) inverters were introduced to integrate both the advantages of Z-source inverters and NPC inverters. However, traditional Z-source inverters suffer from high voltage stress and chopping input current. This paper proposes six types transformer-based impedance......-source NPC inverters which have enhanced voltage boost capability and continuous input current by utilizing of transformer and embedded dc source configuration. Experimental results are presented to verify the theory validation....
Chen Fangfang
2012-09-01
Full Text Available Abstract Background Based on binding of invariant chain (Ii to major histocompatibility complex (MHC class II molecules to form complexes, Ii-segment hybrids, Ii-key structure linking an epitope, or Ii class II-associated invariant chain peptide (CLIP replaced with an epitope were used to increase immune response. It is currently unknown whether the Ii-segment cytosolic and transmembrane domains bind to the MHC non-peptide binding region (PBR and consequently influence immune response. To investigate the potential role of Ii-segments in the immune response via MHC II/peptide complexes, a few hybrids containing Ii-segments and a multiepitope (F306 from Newcastle disease virus fusion protein (F were constructed, and their binding effects on MHC II molecules and specific antibody production were compared using confocal microscopy, immunoprecipitation, western blotting and animal experiments. Results One of the Ii-segment/F306 hybrids, containing ND (Asn–Asp outside the F306 in the Ii-key structure (Ii-key/F306/ND, neither co-localized with MHC II molecules on plasma membrane nor bound to MHC II molecules to form complexes. However, stimulation of mice with the structure produced 4-fold higher antibody titers compared with F306 alone. The two other Ii-segment/F306 hybrids, in which the transmembrane and cytosolic domains of Ii were linked to this structure (Cyt/TM/Ii-key/F306/ND, partially co-localized on plasma membrane with MHC class II molecules and weakly bound MHC II molecules to form complexes. They induced mice to produce approximately 9-fold higher antibody titers compared with F306 alone. Furthermore, an Ii/F306 hybrid (F306 substituting CLIP co-localized well with MHC II molecules on the membrane to form complexes, although it increased antibody titer about 3-fold relative to F306 alone. Conclusions These results suggest that Ii-segments improve specific immune response by binding to the non-PBR on MHC class II molecules and enabling
The study of CP violation in beauty decay is one of the key challenges facing high energy physics. Much work has not yielded a definitive answer how this study might best be performed. However, one clear conclusion is that new accelerator facilities are needed. Proposals include experiments at asymmetric electron-positron colliders and in fixed-target and collider modes at LHC and SSC. Fixed-target and collider experiments at existing accelerators, while they might succeed in a first observation of the effect, will not be adequate to study it thoroughly. Giomataris has emphasized the potential of a new approach to the study of beauty CP violation: the asymmetric proton collider. Such a collider might be realized by the construction of a small storage ring intersecting an existing or soon-to-exist large synchrotron, or by arranging collisions between a large synchrotron and its injector. An experiment at such a collider can combine the advantages of fixed-target-like spectrometer geometry, facilitating triggering, particle identification and the instrumentation of a large acceptance, while the increased √s can provide a factor > 100 increase in beauty-production cross section compared to Tevatron or HERA fixed-target. Beams crossing at a non-zero angle can provide a small interaction region, permitting a first-level decay-vertex trigger to be implemented. To achieve large √s with a large Lorentz boost and high luminosity, the most favorable venue is the high-energy booster (HEB) at the SSC Laboratory, though the CERN SPS and Fermilab Tevatron are also worth considering
Boosted Horizon of a Boosted Space-Time Geometry
Battista, Emmanuele; Scudellaro, Paolo; Tramontano, Francesco
2015-01-01
We apply the ultrarelativistic boosting procedure to map the metric of Schwarzschild-de Sitter spacetime into a metric describing de Sitter spacetime plus a shock-wave singularity located on a null hypersurface, by exploiting the picture of the embedding of an hyperboloid in a five-dimensional Minkowski spacetime. After reverting to the usual four-dimensional formalism, we also solve the geodesic equation and evaluate the Riemann curvature tensor of the boosted Schwarzschild-de Sitter metric by means of numerical calculations, which make it possible to reach the ultrarelativistic regime gradually by letting the boost velocity approach the speed of light. Eventually, the analysis of the Kretschmann invariant (and of the geodesic equation) shows the global structure of space- time, as we demonstrate the presence of a "scalar curvature singularity" within a 3-sphere and find that it is also possible to define what we have called "boosted horizon", a sort of elastic wall where all particles are surprisingly pushe...
Riemann curvature of a boosted spacetime geometry
Battista, Emmanuele; Scudellaro, Paolo; Tramontano, Francesco
2014-01-01
The ultrarelativistic boosting procedure had been applied in the literature to map the metric of Schwarzschild-de Sitter spacetime into a metric describing de Sitter spacetime plus a shock-wave singularity located on a null hypersurface. This paper evaluates the Riemann curvature tensor of the boosted Schwarzschild-de Sitter metric by means of numerical calculations, which make it possible to reach the ultrarelativistic regime gradually by letting the boost velocity approach the speed of light. Thus, for the first time in the literature, the singular limit of curvature through Dirac's delta distribution and its derivatives is numerically evaluated for this class of spacetimes. Eventually, the analysis of the Kteschmann invariant and the geodesic equation show that the spacetime possesses a scalar curvature singularity within a 3-sphere and it is possible to define what we here call boosted horizon, a sort of elastic wall where all particles are surprisingly pushed away, as numerical analysis demonstrates. Thi...
To boost or not boost in radiotherapy
The aim of this paper it to analyse and discuss standard definition of the 'boost' procedure in relation to clinical results and new forms of the boost designed on physical and radiobiological bases. Seventeen sets of clinical data including over 5000 cases cancer with different tumour stages and locations and treated with various forms of 'boost' method have been subtracted from literature. Effectiveness of boost is analyzed regarding its place in combined treatment, timing and subvolume involved. Radiobiological parameter of D10 and normalization method for biologically equivalent doses and dose intensity are used to simulated cold and not subvolumes (hills and dales) and its influence of effectiveness on the boost delivery. Sequential and concomitant boost using external irradiation, although commonly used, offers LTC benefit lower than expected. Brachytherapy, intraoperative irradiation and concurrent chemotherapy boost methods appear more effective. Conformal radiotherapy, with or without dose-intensity modulation, allows heterogeneous increase in dose intensity within the target volume and can be used to integrate the 'boost dose' into baseline treatment (Simultaneous Integrated Boost and SIB). Analysis of interrelationships between boost-dose; boost volume and its timing shows that a TCP benefit from boosting can be expected when a relatively large part of the target volume is involved. Increase in boost dose above 1.2-1.3 of baseline dose using 'standard' methods does not substantially further increase the achieved TCP benefit unless hypoxic cells are a problem. Any small uncertainties in treatment planning can ruin all potential beneficial effect of the boost. For example, a 50% dose deficit in a very small (e.g. 1%) volume of target can decrease TCP to zero. Therefore boost benefits should be carefully weighed against any risk of cold spots in the target volume. Pros and cons in discussion of the role of boost in radiotherapy lead to the important
New approaches for boosting to uniformity
The use of multivariate classifiers has become commonplace in particle physics. To enhance the performance, a series of classifiers is typically trained; this is a technique known as boosting. This paper explores several novel boosting methods that have been designed to produce a uniform selection efficiency in a chosen multivariate space. Such algorithms have a wide range of applications in particle physics, from producing uniform signal selection efficiency across a Dalitz-plot to avoiding the creation of false signal peaks in an invariant mass distribution when searching for new particles
Boosting foundations and algorithms
Schapire, Robert E
2012-01-01
Boosting is an approach to machine learning based on the idea of creating a highly accurate predictor by combining many weak and inaccurate "rules of thumb." A remarkably rich theory has evolved around boosting, with connections to a range of topics, including statistics, game theory, convex optimization, and information geometry. Boosting algorithms have also enjoyed practical success in such fields as biology, vision, and speech processing. At various times in its history, boosting has been perceived as mysterious, controversial, even paradoxical.
Mukherjee, Arindam
2015-01-01
If you are a C++ programmer who has never used Boost libraries before, this book will get you up-to-speed with using them. Whether you are developing new C++ software or maintaining existing code written using Boost libraries, this hands-on introduction will help you decide on the right library and techniques to solve your practical programming problems.
A more robust boosting algorithm
Freund, Yoav
2009-01-01
We present a new boosting algorithm, motivated by the large margins theory for boosting. We give experimental evidence that the new algorithm is significantly more robust against label noise than existing boosting algorithm.
Orientation invariant features for multiclass object recognition
Villamizar, Michael; Sanfeliu, Alberto; Andrade-Cetto, J.
2006-01-01
We present a framework for object recognition based on simple scale and orientation invariant local features that when combined with a hierarchical multiclass boosting mechanism produce robust classifiers for a limited number of object classes in cluttered backgrounds. The system extracts the most relevant features from a set of training samples and builds a hierarchical structure of them. By focusing on those features common to all trained objects, and also searching for those features parti...
Galilea relativity and its invariant bilinear forms
Ratsimbarison, Herintsitohaina
2006-01-01
We construct the family of bilinear forms gG on R3+1 for which Galilea boosts and spatial rotations are isometries. The key feature of these bilinear forms is that they are parametrized by a Galilea invariant vector whose physical interpretation is rather unclear. At the end of the paper, we construct the Poisson bracket associated to the (nondegenerate) antisymmetric part of gG.
Beygelzimer, Alina; Hazan, Elad; Kale, Satyen; Luo, Haipeng
2015-01-01
We extend the theory of boosting for regression problems to the online learning setting. Generalizing from the batch setting for boosting, the notion of a weak learning algorithm is modeled as an online learning algorithm with linear loss functions that competes with a base class of regression functions, while a strong learning algorithm is an online learning algorithm with convex loss functions that competes with a larger class of regression functions. Our main result is an online gradient b...
A boosted Kerr black hole solution and the structure of a general astrophysical black hole
Soares, Ivano Damião
2016-01-01
A solution of Einstein's vacuum field equations that describes a boosted Kerr black hole relative to an asymptotic Lorentz frame at the future null infinity is derived. The solution has three parameters (mass, rotation and boost) and corresponds to the most general configuration that an astrophysical black hole must have; it reduces to the Kerr solution when the boost parameter is zero. In this solution the ergosphere is north-south asymmetric, with dominant lobes in the direction opposite to the boost. However the event horizon, the Cauchy horizon and the ring singularity {\\bf --} which are the core of the black hole structure {\\bf --} do not alter, being independent of the boost parameter. Possible consequences for astrophysical processes connected with Penrose processes in the asymmetric ergosphere are discussed.
Higher dimensional gravity invariant under the AdS group
Salgado, Patricio; Izaurieta, Fernando; Rodriguez, Eduardo
2003-01-01
A higher dimensional gravity invariant both under local Lorentz rotations and under local Anti de Sitter boosts is constructed. It is shown that such a construction is possible both when odd dimensions and when even dimensions are considered. It is also proved that such actions have the same coefficients as those obtained by Troncoso and Zanelli.
Six transformer based asymmetrical embedded Z-source inverters
Wei, Mo; Poh Chiang, Loh; Chi, Jin; Peng, Wang; Blaabjerg, Frede
Embedded/Asymmetrical embedded Z-source inverters were proposed to maintain smooth input current/voltage across the dc source and within the impedance network, remain the shoot-through feature used to boost up the dc-link voltage without adding bulky filter at input side. This paper introduces a ...... class of transformer based asymmetrical embedded Z-source inverters which keep the smooth input current and voltage while achieving enhanced voltage boost capability. The presented inverters are verified by laboratory prototypes experimentally....
Earlier this year, a report by a specially-formed subcommittee of the US Nuclear Science Advisory Committee gave an important boost to the proposal to build a high intensity particle beam 'factory' at the Canadian TRIUMF laboratory in Vancouver. (orig./HSI).
Computational invariant theory
Derksen, Harm
2015-01-01
This book is about the computational aspects of invariant theory. Of central interest is the question how the invariant ring of a given group action can be calculated. Algorithms for this purpose form the main pillars around which the book is built. There are two introductory chapters, one on Gröbner basis methods and one on the basic concepts of invariant theory, which prepare the ground for the algorithms. Then algorithms for computing invariants of finite and reductive groups are discussed. Particular emphasis lies on interrelations between structural properties of invariant rings and computational methods. Finally, the book contains a chapter on applications of invariant theory, covering fields as disparate as graph theory, coding theory, dynamical systems, and computer vision. The book is intended for postgraduate students as well as researchers in geometry, computer algebra, and, of course, invariant theory. The text is enriched with numerous explicit examples which illustrate the theory and should be ...
Breast boost - why, how, when...?
Background: Breast conservation management including tumorectomy or quadrantectomy and external beam radiotherapy with a dose of 45 to 50 Gy in the treatment of small breast carcinomas is generally accepted. The use of a radiation boost - in particular for specific subgroups - has not been clarified. With regard to the boost technique there is some controversy between groups emphasizing the value of electron boost treatment and groups pointing out the value of interstitial boost treatment. This controversy has become even more complicated as there is an increasing number of institutions reporting the use of HDR interstitial brachytherapy for boost treatment. The most critical issue with regard to interstitial HDR brachytherapy is the assumed serious long-term morbidity after a high single radiation dose as used in HDR-treatments. Methods and Results: This article gives a perspective and recommendations on some aspects of this issue (indication, timing, target volume, dose and dose rate). Conclusion: More information about the indication for a boost is to be expected from the EORTC trial 22881/10882. Careful selection of treatment procedures for specific subgroups of patients and refinement in surgical procedures and radiotherapy techniques may be useful in improving the clinical and cosmetic results in breast conservation therapy. Prospective trials comparing on the one hand different boost techniques and on the other hand particular morphologic criteria in treatments with boost and without boost are needed to give more detailed recommendations for boost indication and for boost techniques. (orig.)
Diversity-Based Boosting Algorithm
Jafar A. Alzubi
2016-05-01
Full Text Available Boosting is a well known and efficient technique for constructing a classifier ensemble. An ensemble is built incrementally by altering the distribution of training data set and forcing learners to focus on misclassification errors. In this paper, an improvement to Boosting algorithm called DivBoosting algorithm is proposed and studied. Experiments on several data sets are conducted on both Boosting and DivBoosting. The experimental results show that DivBoosting is a promising method for ensemble pruning. We believe that it has many advantages over traditional boosting method because its mechanism is not solely based on selecting the most accurate base classifiers but also based on selecting the most diverse set of classifiers.
Boosting Support Vector Machines
Elkin Eduardo García Díaz
2006-11-01
Full Text Available En este artículo, se presenta un algoritmo de clasificación binaria basado en Support Vector Machines (Máquinas de Vectores de Soporte que combinado apropiadamente con técnicas de Boosting consigue un mejor desempeño en cuanto a tiempo de entrenamiento y conserva características similares de generalización con un modelo de igual complejidad pero de representación más compacta./ In this paper we present an algorithm of binary classification based on Support Vector Machines. It is combined with a modified Boosting algorithm. It run faster than the original SVM algorithm with a similar generalization error and equal complexity model but it has more compact representation.
Analytic Boosted Boson Discrimination
Larkoski, Andrew J; Neill, Duff
2015-01-01
Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, $D_2$, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits. By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted $Z...
Analytic boosted boson discrimination
Andrew J. Larkoski; Moult, Ian; Neill, Duff
2015-01-01
Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, $D_2$, valid for both signal and background jets. Our factorization t...
Stark, Giordon; The ATLAS collaboration
2016-01-01
In this talk, I present a discussion of techniques used in supersymmetry searches in papers published by the ATLAS Collaboration from late Run 1 to early Run 2. The goal is to highlight concepts the analyses have in common, why/how they work, and possible SUSY searches that could benefit from boosted studies. Theoretical background will be provided for reference to encourage participants to explore in depth on their own time.
StructBoost: Boosting Methods for Predicting Structured Output Variables.
Chunhua Shen; Guosheng Lin; van den Hengel, Anton
2014-10-01
Boosting is a method for learning a single accurate predictor by linearly combining a set of less accurate weak learners. Recently, structured learning has found many applications in computer vision. Inspired by structured support vector machines (SSVM), here we propose a new boosting algorithm for structured output prediction, which we refer to as StructBoost. StructBoost supports nonlinear structured learning by combining a set of weak structured learners. As SSVM generalizes SVM, our StructBoost generalizes standard boosting approaches such as AdaBoost, or LPBoost to structured learning. The resulting optimization problem of StructBoost is more challenging than SSVM in the sense that it may involve exponentially many variables and constraints. In contrast, for SSVM one usually has an exponential number of constraints and a cutting-plane method is used. In order to efficiently solve StructBoost, we formulate an equivalent 1-slack formulation and solve it using a combination of cutting planes and column generation. We show the versatility and usefulness of StructBoost on a range of problems such as optimizing the tree loss for hierarchical multi-class classification, optimizing the Pascal overlap criterion for robust visual tracking and learning conditional random field parameters for image segmentation. PMID:26352637
Meyer, Mathieu; Schuett, Carsten; Werner, Elisabeth M.
2013-01-01
An affine invariant point on the class of convex bodies in R^n, endowed with the Hausdorff metric, is a continuous map p which is invariant under one-to-one affine transformations A on R^n, that is, p(A(K))=A(p(K)). We define here the new notion of dual affine point q of an affine invariant point p by the formula q(K^{p(K)})=p(K) for every convex body K, where K^{p(K)} denotes the polar of K with respect to p(K). We investigate which affine invariant points do have a dual point, whether this ...
Asymmetric Gepner Models (Revisited)
Gato-Rivera, B
2010-01-01
We reconsider a class of heterotic string theories studied in 1989, based on tensor products of N=2 minimal models with asymmetric simple current invariants. We extend this analysis from (2,2) and (1,2) spectra to (0,2) spectra with SO(10) broken to the Standard Model. In the latter case the spectrum must contain fractionally charged particles. We find that in nearly all cases at least some of them are massless. However, we identify a large subclass where the fractional charges are at worst half-integer, and often vector-like. The number of families is very often reduced in comparison to the 1989 results, but there are no new tensor combinations yielding three families. All tensor combinations turn out to fall into two classes: those where the number of families is always divisible by three, and those where it is never divisible by three. We find an empirical rule to determine the class, which appears to extend beyond minimal N=2 tensor products. We observe that distributions of physical quantities such as th...
Attractiveness of Invariant Manifolds
Pei, Lijun
2011-01-01
In this paper an operable, universal and simple theory on the attractiveness of the invariant manifolds is first obtained. It is motivated by the Lyapunov direct method. It means that for any point $\\overrightarrow{x}$ in the invariant manifold $M$, $n(\\overrightarrow{x})$ is the normal passing by $\\overrightarrow{x}$, and $\\forall \\overrightarrow{x^{'}} \\in n(\\overrightarrow{x})$, if the tangent $f(\\overrightarrow{x^{'}})$ of the orbits of the dynamical system intersects at obtuse (sharp) angle with the normal $n(\\overrightarrow{x})$, or the inner product of the normal vector $\\overrightarrow{n}(\\overrightarrow{x})$ and tangent vector $\\overrightarrow{f}(\\overrightarrow{x^{'}})$ is negative (positive), i.e., $\\overrightarrow{f}(\\overrightarrow{x^{'}}). \\overrightarrow{n}(\\overrightarrow{x}) )0$, then the invariant manifold $M$ is attractive (repulsive). Some illustrative examples of the invariant manifolds, such as equilibria, periodic solution, stable and unstable manifolds, other invariant manifold are pre...
Generalized relativistic kinematics in Poincar\\'e-invariant models
Ivetic, B; Samsarov, A
2016-01-01
Assuming the validity of the relativity principle, we discuss the implications on relativistic kinematics of a deformation of the Poincar\\'e invariance that preserves the Poincar\\'e algebra, and only modifies its action on phase space in a Lorentz-invariant way. We show that, in contrast to the case where the Poincar\\'e algebra is deformed, the action of boosts on two-particle states is not affected, while the addition law of momenta is to a large extent arbitrary. We give some nontrivial examples of this arising from doubly special relativity and noncommutative geometry and show that Hopf-algebra methods give equivalent results.
Boost C++ application development cookbook
Polukhin, Antony
2013-01-01
This book follows a cookbook approach, with detailed and practical recipes that use Boost libraries.This book is great for developers new to Boost, and who are looking to improve their knowledge of Boost and see some undocumented details or tricks. It's assumed that you will have some experience in C++ already, as well being familiar with the basics of STL. A few chapters will require some previous knowledge of multithreading and networking. You are expected to have at least one good C++ compiler and compiled version of Boost (1.53.0 or later is recommended), which will be used during the exer
Gradient boosting machines, a tutorial.
Natekin, Alexey; Knoll, Alois
2013-01-01
Gradient boosting machines are a family of powerful machine-learning techniques that have shown considerable success in a wide range of practical applications. They are highly customizable to the particular needs of the application, like being learned with respect to different loss functions. This article gives a tutorial introduction into the methodology of gradient boosting methods with a strong focus on machine learning aspects of modeling. A theoretical information is complemented with descriptive examples and illustrations which cover all the stages of the gradient boosting model design. Considerations on handling the model complexity are discussed. Three practical examples of gradient boosting applications are presented and comprehensively analyzed. PMID:24409142
Gradient Boosting Machines, A Tutorial
Alexey eNatekin
2013-12-01
Full Text Available Gradient boosting machines are a family of powerful machine-learning techniques that have shown considerable success in a wide range of practical applications. They are highly customizable to the particular needs of the application, like being learned with respect to different loss functions. This article gives a tutorial introduction into the methodology of gradient boosting methods. A theoretical information is complemented with many descriptive examples and illustrations which cover all the stages of the gradient boosting model design. Considerations on handling the model complexity are discussed. A set of practical examples of gradient boosting applications are presented and comprehensively analyzed.
Analytic boosted boson discrimination
Larkoski, Andrew J.; Moult, Ian; Neill, Duff
2016-05-01
Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, D 2, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits. By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted Z boson from massive QCD background jets. We compare our results with Monte Carlo predictions which allows for a detailed understanding of the extent to which these generators accurately describe the formation of two-prong QCD jets, and informs their usage in substructure analyses. Our calculation also provides considerable insight into the discrimination power and calculability of jet substructure observables in general.
Morozov, Albert D; Dragunov, Timothy N; Malysheva, Olga V
1999-01-01
This book deals with the visualization and exploration of invariant sets (fractals, strange attractors, resonance structures, patterns etc.) for various kinds of nonlinear dynamical systems. The authors have created a special Windows 95 application called WInSet, which allows one to visualize the invariant sets. A WInSet installation disk is enclosed with the book.The book consists of two parts. Part I contains a description of WInSet and a list of the built-in invariant sets which can be plotted using the program. This part is intended for a wide audience with interests ranging from dynamical
Transformation invariance in pattern recognition - tangent distance and tangent propagation
Simard, Patrice,; Le Cun, Yann; Denker, John,; Victorri, Bernard
1998-01-01
http://research.microsoft.com/~patrice/PDF/tricks.pdf In pattern recognition, statistical modeling, or regression, the amount of data is the most critical factor affecting the performance. If the amount of data and computational resources are near infinite, many algorithmes will probably converge to the optimal solution. When this is not the case, one has to introduce regularizers and a-priori knowledge to supplement the available data in order to boost the performance. Invariance (or know...
Relativistic gauge invariant potentials
A global method characterizing the invariant connections on an abelian principal bundle under a group of transformations is applied in order to get gauge invariant electromagnetic (elm.) potentials in a systematic way. So, we have classified all the elm. gauge invariant potentials under the Poincare subgroups of dimensions 4, 5, and 6, up to conjugation. It is paid attention in particular to the situation where these subgroups do not act transitively on the space-time manifold. We have used the same procedure for some galilean subgroups to get nonrelativistic potentials and study the way they are related to their relativistic partners by means of contractions. Some conformal gauge invariant potentials have also been derived and considered when they are seen as consequence of an enlargement of the Poincare symmetries. (orig.)
Ultrarelativistic boost with scalar field
Svítek, O.; Tahamtan, T.
2016-02-01
We present the ultrarelativistic boost of the general global monopole solution which is parametrized by mass and deficit solid angle. The problem is addressed from two different perspectives. In the first one the primary object for performing the boost is the metric tensor while in the second one the energy momentum tensor is used. Since the solution is sourced by a triplet of scalar fields that effectively vanish in the boosting limit we investigate the behavior of a scalar field in a simpler setup. Namely, we perform the boosting study of the spherically symmetric solution with a free scalar field given by Janis, Newman and Winicour. The scalar field is again vanishing in the limit pointing to a broader pattern of scalar field behaviour during an ultrarelativistic boost in highly symmetric situations.
In gluon fusion both a modified top Yukawa and new colored particles can alter the cross section. However in a large set of composite Higgs models and in realistic areas of the MSSM parameter space, these two effects can conspire and hide new physics in a Standard Model-like inclusive cross section. We first show that it is possible to break this degeneracy in the couplings by demanding a boosted Higgs recoiling against a high-pT jet. Subsequently we propose an analysis based on this idea in the H→2l+ET channels. This measurement allows an alternative determination of the important top Yukawa besides the t anti tH channel.
The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of H→2l+pT via H→ττ and H→WW* could be performed and demonstrate that it offers a compelling alternative to the t anti tH channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section.
2006-11-01
that oscillate in certain directions. Reflection or scattering of light favours certain orientations of the electric and magnetic fields over others. This is why polarising sunglasses can filter out the glint of sunlight reflected off a pond. When light scatters through the expanding debris of a supernova, it retains information about the orientation of the scattering layers. If the supernova is spherically symmetric, all orientations will be present equally and will average out, so there will be no net polarisation. If, however, the gas shell is not round, a slight net polarisation will be imprinted on the light. This is what broad-band polarimetry can accomplish. If additional spectral information is available ('spectro-polarimetry'), one can determine whether the asymmetry is in the continuum light or in some spectral lines. In the case of the Type Ia supernovae, the astronomers found that the continuum polarisation is very small so that the overall shape of the explosion is crudely spherical. But the much larger polarization in strongly blue-shifted spectral lines evidences the presence, in the outer regions, of fast moving clumps with peculiar chemical composition. "Our study reveals that explosions of Type Ia supernovae are really three-dimensional phenomena," says Dietrich Baade. "The outer regions of the blast cloud is asymmetric, with different materials found in 'clumps', while the inner regions are smooth." "This study was possible because polarimetry could unfold its full strength thanks to the light-collecting power of the Very Large Telescope and the very precise calibration of the FORS instrument," he adds. The research team first spotted this asymmetry in 2003, as part of the same observational campaign (ESO PR 23/03 and ESO PR Photo 26/05). The new, more extensive results show that the degree of polarisation and, hence, the asphericity, correlates with the intrinsic brightness of the explosion. The brighter the supernova, the smoother, or less clumpy
Detection of Illegitimate Emails using Boosting Algorithm
Nizamani, Sarwat; Memon, Nasrullah; Wiil, Uffe Kock
2011-01-01
spam email detection. For our desired task, we have applied a boosting technique. With the use of boosting we can achieve high accuracy of traditional classification algorithms. When using boosting one has to choose a suitable weak learner as well as the number of boosting iterations. In this paper, we...... propose a Naive Bayes classifier as a suitable weak learner for the boosting algorithm. It achieves maximum performance with very few boosting iterations....
Asymmetric Gepner models (revisited)
Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain)] [IMAPP, Radboud Universiteit, Nijmegen (Netherlands)
2010-12-11
We reconsider a class of heterotic string theories studied in 1989, based on tensor products of N=2 minimal models with asymmetric simple current invariants. We extend this analysis from (2,2) and (1,2) spectra to (0,2) spectra with SO(10) broken to the Standard Model. In the latter case the spectrum must contain fractionally charged particles. We find that in nearly all cases at least some of them are massless. However, we identify a large subclass where the fractional charges are at worst half-integer, and often vector-like. The number of families is very often reduced in comparison to the 1989 results, but there are no new tensor combinations yielding three families. All tensor combinations turn out to fall into two classes: those where the number of families is always divisible by three, and those where it is never divisible by three. We find an empirical rule to determine the class, which appears to extend beyond minimal N=2 tensor products. We observe that distributions of physical quantities such as the number of families, singlets and mirrors have an interesting tendency towards smaller values as the gauge groups approaches the Standard Model. We compare our results with an analogous class of free fermionic models. This displays similar features, but with less resolution. Finally we present a complete scan of the three family models based on the triply-exceptional combination (1,16{sup *},16{sup *},16{sup *}) identified originally by Gepner. We find 1220 distinct three family spectra in this case, forming 610 mirror pairs. About half of them have the gauge group SU(3)xSU(2){sub L}xSU(2){sub R}xU(1){sup 5}, the theoretical minimum, and many others are trinification models.
Physics with boosted top quarks
Kuutmann, Elin Bergeaas
2014-01-01
The production at the LHC of boosted top quarks (top quarks with a transverse momentum that greatly exceeds their rest mass) is a promising process to search for phenomena beyond the Standard Model. In this contribution several examples are discussed of new techniques to reconstruct and identify (tag) the collimated decay topology of the boosted hadronic decays of top quarks. Boosted top reconstruction techniques have been utilized in searches for new physical phenomena. An overview is given of searches by ATLAS, CDF and CMS for heavy new particles decaying into a top and an anti-top quark, vector-like quarks and supersymmetric partners to the top quark.
Invariant facial feature extraction using biologically inspired strategies
Du, Xing; Gong, Weiguo
2011-12-01
In this paper, a feature extraction model for face recognition is proposed. This model is constructed by implementing three biologically inspired strategies, namely a hierarchical network, a learning mechanism of the V1 simple cells, and a data-driven attention mechanism. The hierarchical network emulates the functions of the V1 cortex to progressively extract facial features invariant to illumination, expression, slight pose change, and variations caused by local transformation of facial parts. In the network, filters that account for the local structures of the face are derived through the learning mechanism and used for the invariant feature extraction. The attention mechanism computes a saliency map for the face, and enhances the salient regions of the invariant features to further improve the performance. Experiments on the FERET and AR face databases show that the proposed model boosts the recognition accuracy effectively.
Transformation invariant sparse coding
Mørup, Morten; Schmidt, Mikkel Nørgaard
2011-01-01
Sparse coding is a well established principle for unsupervised learning. Traditionally, features are extracted in sparse coding in specific locations, however, often we would prefer invariant representation. This paper introduces a general transformation invariant sparse coding (TISC) model. The...... model decomposes images into features invariant to location and general transformation by a set of specified operators as well as a sparse coding matrix indicating where and to what degree in the original image these features are present. The TISC model is in general overcomplete and we therefore invoke...... sparse coding to estimate its parameters. We demonstrate how the model can correctly identify components of non-trivial artificial as well as real image data. Thus, the model is capable of reducing feature redundancies in terms of pre-specified transformations improving the component identification....
NIMET PANCAROGLU; FATIH NURAY
2013-01-01
In this paper, we define invariant convergence, lacunary invariant convergence, invariant statistical convergence, lacunary invariant statistical convergence for sequences of sets. We investigate some relations between lacunary invariant statistical convergence and invariant statistical convergence for sequences of sets.
Illumination Invariant Unsupervised Segmenter
Haindl, Michal; Mikeš, Stanislav; Vácha, Pavel
Los Alamitos : IEEE, 2009, s. 4025-4028. ISBN 978-1-4244-5655-0. ISSN 1522-4880. [ICIP 2009. Cairo (EG), 07.11.2009-11.11.2009] R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593 Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : unsupervised image segmentation * Illumination Invariants Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2009/RO/haindl-illumination invariant unsupervised segmenter.pdf
Pérez-Nadal, Guillem
2016-01-01
We consider a non-relativistic free scalar field theory with a type of anisotropic scale invariance in which the number of coordinates "scaling like time" is generically greater than one. We propose the Cartesian product of two curved spaces, with the metric of each space parameterized by the other space, as a notion of curved background to which the theory can be extended. We study this type of geometries, and find a family of extensions of the theory to curved backgrounds in which the anisotropic scale invariance is promoted to a local, Weyl-type symmetry.
Distribution-Specific Agnostic Boosting
Feldman, Vitaly
2009-01-01
We consider the problem of boosting the accuracy of weak learning algorithms in the agnostic learning framework of Haussler (1992) and Kearns et al. (1992). Known algorithms for this problem (Ben-David et al., 2001; Gavinsky, 2002; Kalai et al., 2008) follow the same strategy as boosting algorithms in the PAC model: the weak learner is executed on the same target function but over different distributions on the domain. We demonstrate boosting algorithms for the agnostic learning framework that only modify the distribution on the labels of the points (or, equivalently, modify the target function). This allows boosting a distribution-specific weak agnostic learner to a strong agnostic learner with respect to the same distribution. When applied to the weak agnostic parity learning algorithm of Goldreich and Levin (1989) our algorithm yields a simple PAC learning algorithm for DNF and an agnostic learning algorithm for decision trees over the uniform distribution using membership queries. These results substantia...
Rosacea Might Boost Parkinson's Risk
... medlineplus/news/fullstory_157883.html Rosacea Might Boost Parkinson's Risk: Study Research found an association, but did ... may be linked to an increased risk for Parkinson's disease, a large, new study suggests. Among more ...
Gradient boosting machines, a tutorial
Natekin, Alexey; Knoll, Alois
2013-01-01
Gradient boosting machines are a family of powerful machine-learning techniques that have shown considerable success in a wide range of practical applications. They are highly customizable to the particular needs of the application, like being learned with respect to different loss functions. This article gives a tutorial introduction into the methodology of gradient boosting methods with a strong focus on machine learning aspects of modeling. A theoretical information is complemented with de...
Gradient Boosting Machines, A Tutorial
Alexey Natekin; Alois Knoll
2013-01-01
Gradient boosting machines are a family of powerful machine-learning techniques that have shown considerable success in a wide range of practical applications. They are highly customizable to the particular needs of the application, like being learned with respect to different loss functions. This article gives a tutorial introduction into the methodology of gradient boosting methods. A theoretical information is complemented with many descriptive examples and illustrations which cover all th...
Kameko, Masaki
2012-01-01
For any odd prime $p$, we prove that the induced homomorphism from the mod $p$ cohomology of the classifying space of a compact simply-connected simple connected Lie group to the Weyl group invariants of the mod $p$ cohomology of the classifying space of its maximal torus is an epimorphism except for the case $p=3$, $G=E_8$.
Relativistically invariant quantum information
Bartlett, Stephen D.; Terno, Daniel R.
2004-01-01
We show that quantum information can be encoded into entangled states of multiple indistinguishable particles in such a way that any inertial observer can prepare, manipulate, or measure the encoded state independent of their Lorentz reference frame. Such relativistically invariant quantum information is free of the difficulties associated with encoding into spin or other degrees of freedom in a relativistic context.
Modular invariant gaugino condensation
The construction of effective supergravity lagrangians for gaugino condensation is reviewed and recent results are presented that are consistent with modular invariance and yield a positive definite potential of the noscale type. Possible implications for phenomenology are briefly discussed. 29 refs
Wetterich, C
2016-01-01
We propose a gauge invariant flow equation for Yang-Mills theories and quantum gravity that only involves one macroscopic gauge field or metric. It is based on a projection on physical and gauge fluctuations, corresponding to a particular gauge fixing. The freedom in the precise choice of the macroscopic field can be exploited in order to keep the flow equation simple.
Galilei invariant molecular dynamics
We construct a C*-dynamical model for a chemical reaction. Galilei invariance of our nonrelativistic model is demonstrated by defining it directly on a Galilean space-time fibrebundle with C*-algebra valued fibre, i.e. without reference to any coordinate system. The existence of equilibrium states in this model is established and some of their properties are discussed. (orig.)
Kobayashi, Tatsuo; Nitta, Daisuke; Urakawa, Yuko
2016-08-01
Modular invariance is a striking symmetry in string theory, which may keep stringy corrections under control. In this paper, we investigate a phenomenological consequence of the modular invariance, assuming that this symmetry is preserved as well as in a four dimensional (4D) low energy effective field theory. As a concrete setup, we consider a modulus field T whose contribution in the 4D effective field theory remains invariant under the modular transformation and study inflation drived by T. The modular invariance restricts a possible form of the scalar potenntial. As a result, large field models of inflation are hardly realized. Meanwhile, a small field model of inflation can be still accomodated in this restricted setup. The scalar potential traced during the slow-roll inflation mimics the hilltop potential Vht, but it also has a non-negligible deviation from Vht. Detecting the primordial gravitational waves predicted in this model is rather challenging. Yet, we argue that it may be still possible to falsify this model by combining the information in the reheating process which can be determined self-completely in this setup.
Modifications of Paroemia Invariants
Taliya F. Pecherskikh
2013-01-01
Full Text Available The phenomenon of modifications of paroemia invariants proves that language constantly changes and develops. The realization of communication need through the new evocative forms of expression is generality of the opposite linguistic phenomena of occasional variants of paroemia, aimed at the establishment of equilibrium in phraseology.
Kobayashi, Tatsuo; Urakawa, Yuko
2016-01-01
Modular invariance is a striking symmetry in string theory, which may keep stringy corrections under control. In this paper, we investigate a phenomenological consequence of the modular invariance, assuming that this symmetry is preserved as well as in a four dimensional (4D) low energy effective field theory. As a concrete setup, we consider a modulus field $T$ whose contribution in the 4D effective field theory remains invariant under the modular transformation and study inflation drived by $T$. The modular invariance restricts a possible form of the scalar potenntial. As a result, large field models of inflation are hardly realized. Meanwhile, a small field model of inflation can be still accomodated in this restricted setup. The scalar potential traced during the slow-roll inflation mimics the hilltop potential $V_{ht}$, but it also has a non-negligible deviation from $V_{ht}$. Detecting the primordial gravitational waves predicted in this model is rather challenging. Yet, we argue that it may be still po...
Invariant differential operators
Dobrev, Vladimir K
2016-01-01
With applications in quantum field theory, elementary particle physics and general relativity, this two-volume work studies invariance of differential operators under Lie algebras, quantum groups, superalgebras including infinite-dimensional cases, Schrödinger algebras, applications to holography. This first volume covers the general aspects of Lie algebras and group theory.
Catalytic Asymmetric Total Synthesis of Hedyosumins A, B, and C.
Sun, Wang-Bin; Wang, Xuan; Sun, Bing-Feng; Zou, Jian-Ping; Lin, Guo-Qiang
2016-03-18
The first and asymmetric total synthesis of hedyosumins A, B, and C was accomplished in 13-14 steps from simple starting materials. The essential tools that allow us to access the tetracyclic skeleton include an organocatalytic [4 + 3] cycloaddition reaction, an intramolecular aldol condensation, and an intramolecular carboxymercuration/demercuration enabled lactonization. A CBS-catalyzed asymmetric reduction was employed to boost the ee of the synthetic natural products to an excellent level. This synthesis established the absolute configurations of hedyosumins A, B, and C. PMID:26925758
Continuous Integrated Invariant Inference Project
National Aeronautics and Space Administration — The proposed project will develop a new technique for invariant inference and embed this and other current invariant inference and checking techniques in an...
Invariant types in NIP theories
Simon, Pierre
2014-01-01
We study invariant types in NIP theories. Amongst other things: we prove a definable version of the (p,q)-theorem in theories of small or medium directionality; we construct a canonical retraction from the space of M-invariant types to that of M-finitely satisfiable types; we show some amalgamation results for invariant types and list a number of open questions.
Permutationally invariant state reconstruction
Moroder, Tobias; Toth, Geza; Schwemmer, Christian; Niggebaum, Alexander; Gaile, Stefanie; Gühne, Otfried; Weinfurter, Harald
2012-01-01
Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, also an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a non-linear large-scale optimization problem, this is a major challenge in the design of scalable tomography schemes. Here we present an efficient state reconstruction scheme for permutationally invariant quantum state tomography. It works for all common state-of-the-art reconstruction principles, including, in particular, maximum likelihood and least squares methods, which are the preferred choices in today's experiments. This high efficiency is achieved by greatly reducing the dimensionality of the problem employing a particular representation of permutationally invariant states known from spin coupling combined with convex optimization, which has clear advantages regarding speed, control and accuracy in comparison to commonly employed n...
Invariants for Parallel Mapping
YIN Yajun; WU Jiye; FAN Qinshan; HUANG Kezhi
2009-01-01
This paper analyzes the geometric quantities that remain unchanged during parallel mapping (i.e., mapping from a reference curved surface to a parallel surface with identical normal direction). The second gradient operator, the second class of integral theorems, the Gauss-curvature-based integral theorems, and the core property of parallel mapping are used to derive a series of parallel mapping invadants or geometri-cally conserved quantities. These include not only local mapping invadants but also global mapping invari-ants found to exist both in a curved surface and along curves on the curved surface. The parallel mapping invadants are used to identify important transformations between the reference surface and parallel surfaces. These mapping invadants and transformations have potential applications in geometry, physics, biome-chanics, and mechanics in which various dynamic processes occur along or between parallel surfaces.
Conformal invariance in supergravity
In this thesis the author explains the role of conformal invariance in supergravity. He presents the complete structure of extended conformal supergravity for N <= 4. The outline of this work is as follows. In chapter 2 he briefly summarizes the essential properties of supersymmetry and supergravity and indicates the use of conformal invariance in supergravity. The idea that the introduction of additional symmetry transformations can make clear the structure of a field theory is not reserved to supergravity only. By means of some simple examples it is shown in chapter 3 how one can always introduce additional gauge transformations in a theory of massive vector fields. Moreover it is shown how the gauge invariant formulation sometimes explains the quantum mechanical properties of the theory. In chapter 4 the author defines the conformal transformations and summarizes their main properties. He explains how these conformal transformations can be used to analyse the structure of gravity. The supersymmetric extension of these results is discussed in chapter 5. Here he describes as an example how N=1 supergravity can be reformulated in a conformally-invariant way. He also shows that beyond N=1 the gauge fields of the superconformal symmetries do not constitute an off-shell field representation of extended conformal supergravity. Therefore, in chapter 6, a systematic method to construct the off-shell formulation of all extended conformal supergravity theories with N <= 4 is developed. As an example he uses this method to construct N=1 conformal supergravity. Finally, in chapter 7 N=4 conformal supergravity is discussed. (Auth.)
Tracking Particles in Flows near Invariant Manifolds via Balance Functions
Kuehn, Christian; Kuhlmann, Hendrik C
2016-01-01
Particles moving inside a fluid near, and interacting with, invariant manifolds is a common phenomenon in a wide variety of applications. One elementary question is whether we can determine once a particle has entered a neighbourhood of an invariant manifold, when it leaves again. Here we approach this problem mathematically by introducing balance functions, which relate the entry and exit points of a particle by an integral variational formula. We define, study, and compare different natural choices for balance functions and conclude that an efficient compromise is to employ normal infinitesimal Lyapunov exponents. We apply our results to two different model flows: a regularized solid-body rotational flow and the asymmetric Kuhlmann--Muldoon model developed in the context of liquid bridges. Furthermore, we employ full numerical simulations of the Navier-Stokes equations of a two-way coupled particle in a shear--stress-driven cavity to test balance functions for a particle moving near an invariant wall. In co...
Governor model for asymmetric deformed nuclei
The governor model is extended to include the asymmetric shape of nuclei which allows a simultaneous analysis of the data for both the ground state and the γ-vibrational bands in deformed even-even nuclei. The rotationally invariant core is assumed to be a spheroid with an axis of symmetry parallel to the axis of rotation. The calculations are carried out under the assumption of no stretching. The static γ-deformation results are compared with the VMI(ARM) and Krutov values, and the calculated energies are in good agreement with the experimental data
Braaten, Eric
2015-01-01
XEFT is a low-energy effective field theory for charm mesons and pions that provides a systematically improvable description of the X(3872) resonance. A Galilean-invariant formulation of XEFT is introduced to exploit the fact that mass is very nearly conserved in the transition D*0 --> D0 pi0. The transitions D*0 --> D0 pi0 and X --> D0 D0-bar pi0 are described explicitly in XEFT. The effects of the decay D*0 --> D0 gamma and of short-distance decay modes of the X(3872), such as J/psi --> pi+ pi-, can be taken into account by using complex on-shell renormalization schemes for the D*0 propagator and for the D*0 D0-bar propagator in which the positions of their complex poles are specified. Galilean-invariant XEFT is used to calculate the D*0 D0-bar scattering length to next-to-leading order. Galilean invariance ensures the cancellation of ultraviolet divergences without the need for truncating an expansion in powers of the ratio of the pion and charm meson masses.
Cheng, Miranda C N; Harrison, Sarah M; Kachru, Shamit
2015-01-01
In this note, we describe a connection between the enumerative geometry of curves in K3 surfaces and the chiral ring of an auxiliary superconformal field theory. We consider the invariants calculated by Yau--Zaslow (capturing the Euler characters of the moduli spaces of D2-branes on curves of given genus), together with their refinements to carry additional quantum numbers by Katz--Klemm--Vafa (KKV), and Katz--Klemm--Pandharipande (KKP). We show that these invariants can be reproduced by studying the Ramond ground states of an auxiliary chiral superconformal field theory which has recently been observed to give rise to mock modular moonshine for a variety of sporadic simple groups that are subgroups of Conway's group. We also study equivariant versions of these invariants. A K3 sigma model is specified by a choice of 4-plane in the K3 D-brane charge lattice. Symmetries of K3 sigma models are naturally identified with 4-plane preserving subgroups of the Conway group, according to the work of Gaberdiel--Hoheneg...
Boost.Asio C++ network programming
Torjo, John
2013-01-01
What you want is an easy level of abstraction, which is just what this book provides in conjunction with Boost.Asio. Switching to Boost.Asio is just a few extra #include directives away, with the help of this practical and engaging guide.This book is great for developers that need to do network programming, who don't want to delve into the complicated issues of a raw networking API. You should be familiar with core Boost concepts, such as smart pointers and shared_from_this, resource classes (noncopyable), functors and boost::bind, boost mutexes, and the boost date/time library. Readers should
Invariant operators of inhomogeneous groups
The problems concerning the invariant operators of the W(p, q) Weyl group of arbitrary dimension are considered. The Weyl group relative invariants, which do not contain the dilatation operators and which are the absolute invariants of the ISO (p, q) group, are searched for. The invariant operators of the Weyl group are represented in the form of the ratio of the Cazimir operators of the inhomogeneous pseudoorthogonal subgroup. It is shown that all the invariant operators of the W(p, q) Weyl group are rational and their number is [p+q-1/2
Can you boost your metabolism?
... more calories than fat. So will building more muscle not boost your metabolism? Yes, but only by a small amount. Most ... you burn. Plus, when not in active use, muscles burn very few calories. Most ... most of your metabolism. What to do: Lift weights for stronger bones ...
Thinning Invariant Partition Structures
Starr, Shannon
2011-01-01
A partition structure is a random point process on $[0,1]$ whose points sum to 1, almost surely. In the case that there are infinitely many points to begin with, we consider a thinning action by: first, removing points independently, such that each point survives with probability $p>0$; and, secondly, rescaling the remaining points by an overall factor to normalize the sum again to 1. We prove that the partition structures which are "thinning divisible" for a sequence of $p$'s converging to 0 are mixtures of the Poisson-Kingman partition structures. We also consider the property of being "thinning invariant" for all $p \\in (0,1)$.
Anistropic Invariant FRW Cosmology
Chagoya, J F
2015-01-01
In this paper we study the effects of including anisotropic scaling invariance in the minisuperspace Lagrangian for a universe modelled by the Friedman-Robertson-Walker metric, a massless scalar field and cosmological constant. We find that canonical quantization of this system leads to a Schroedinger type equation, thus avoiding the frozen time problem of the usual Wheeler-DeWitt equation. Furthermore, we find numerical solutions for the classical equations of motion, and we also find evidence that under some conditions the big bang singularity is avoided in this model.
Boosting Applied to Word Sense Disambiguation
Escudero, Gerard; Marquez, Lluis; Rigau, German
2000-01-01
In this paper Schapire and Singer's AdaBoost.MH boosting algorithm is applied to the Word Sense Disambiguation (WSD) problem. Initial experiments on a set of 15 selected polysemous words show that the boosting approach surpasses Naive Bayes and Exemplar-based approaches, which represent state-of-the-art accuracy on supervised WSD. In order to make boosting practical for a real learning domain of thousands of words, several ways of accelerating the algorithm by reducing the feature space are s...
Noncommutative coordinates invariant under rotations and Lorentz transformations
Dynamics with noncommutative coordinates invariant under three-dimensional rotations or, if time is included, under Lorentz transformations is developed. These coordinates turn out to be the boost operators in SO(1,3) or in SO(2,3), respectively. The noncommutativity is governed by a mass parameter M. The principal results are: (i) a modification of the Heisenberg algebra for distances smaller than 1/M, (ii) a lower limit, 1/M, on the localizability of wave packets, (iii) discrete eigenvalues of the coordinate operator in timelike directions, and (iv) an upper limit, M, on the mass for which free field equations have solutions. Possible restrictions on small black holes are discussed
Tractors, mass, and Weyl invariance
Deser and Nepomechie established a relationship between masslessness and rigid conformal invariance by coupling to a background metric and demanding local Weyl invariance, a method which applies neither to massive theories nor theories which rely upon gauge invariances for masslessness. We extend this method to describe massive and gauge invariant theories using Weyl invariance. The key idea is to introduce a new scalar field which is constant when evaluated at the scale corresponding to the metric of physical interest. This technique relies on being able to efficiently construct Weyl invariant theories. This is achieved using tractor calculus-a mathematical machinery designed for the study of conformal geometry. From a physics standpoint, this amounts to arranging fields in multiplets with respect to the conformal group but with novel Weyl transformation laws. Our approach gives a mechanism for generating masses from Weyl weights. Breitenlohner-Freedman stability bounds for Anti-de Sitter theories arise naturally as do direct derivations of the novel Weyl invariant theories given by Deser and Nepomechie. In constant curvature spaces, partially massless theories-which rely on the interplay between mass and gauge invariance-are also generated by our method. Another simple consequence is conformal invariance of the maximal depth partially massless theories. Detailed examples for spins s≤2 are given including tractor and component actions, on-shell and off-shell approaches and gauge invariances. For all spins s≥2 we give tractor equations of motion unifying massive, massless, and partially massless theories
On obtaining strictly invariant Lagrangians from gauge-invariant Lagrangians
Lagrangian dynamical systems are considered on tangent bundles of differentiable manifolds whose Lagrangian functions are gauge invariant under the action of a Lie group on the base manifold. Necessary and sufficient conditions are then obtained for finding a function on the base manifold whose time derivative, if added to the gauge-invariant Lagrangian, yields a strictly invariant one. The problem is transported from the tangent bundle also to the cotangent bundle
Palmer, T N
2016-01-01
Invariant Set Theory (IST) is a realistic, locally causal theory of fundamental physics which assumes a much stronger synergy between cosmology and quantum physics than exists in contemporary theory. In IST the (quasi-cyclic) universe $U$ is treated as a deterministic dynamical system evolving precisely on a measure-zero fractal invariant subset $I_U$ of its state space. In this approach, the geometry of $I_U$, and not a set of differential evolution equations in space-time $\\mathcal M_U$, provides the most primitive description of the laws of physics. As such, IST is non-classical. The geometry of $I_U$ is based on Cantor sets of space-time trajectories in state space, homeomorphic to the algebraic set of $p$-adic integers, for large but finite $p$. In IST, the non-commutativity of position and momentum observables arises from number theory - in particular the non-commensurateness of $\\phi$ and $\\cos \\phi$. The complex Hilbert Space and the relativistic Dirac Equation respectively are shown to describe $I_U$...
Viability, invariance and applications
Carja, Ovidiu; Vrabie, Ioan I
2007-01-01
The book is an almost self-contained presentation of the most important concepts and results in viability and invariance. The viability of a set K with respect to a given function (or multi-function) F, defined on it, describes the property that, for each initial data in K, the differential equation (or inclusion) driven by that function or multi-function) to have at least one solution. The invariance of a set K with respect to a function (or multi-function) F, defined on a larger set D, is that property which says that each solution of the differential equation (or inclusion) driven by F and issuing in K remains in K, at least for a short time.The book includes the most important necessary and sufficient conditions for viability starting with Nagumo's Viability Theorem for ordinary differential equations with continuous right-hand sides and continuing with the corresponding extensions either to differential inclusions or to semilinear or even fully nonlinear evolution equations, systems and inclusions. In th...
Permutationally invariant state reconstruction
Moroder, Tobias; Hyllus, Philipp; Tóth, Géza;
2012-01-01
Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a nonlinear large-scale opti......Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a nonlinear large......-scale optimization problem, this is a major challenge in the design of scalable tomography schemes. Here we present an efficient state reconstruction scheme for permutationally invariant quantum state tomography. It works for all common state-of-the-art reconstruction principles, including, in particular, maximum...... likelihood and least squares methods, which are the preferred choices in today's experiments. This high efficiency is achieved by greatly reducing the dimensionality of the problem employing a particular representation of permutationally invariant states known from spin coupling combined with convex...
Polynomial invariants of quantum codes
Rains, E M
1997-01-01
The weight enumerators (quant-ph/9610040) of a quantum code are quite powerful tools for exploring its structure. As the weight enumerators are quadratic invariants of the code, this suggests the consideration of higher-degree polynomial invariants. We show that the space of degree k invariants of a code of length n is spanned by a set of basic invariants in one-to-one correspondence with S_k^n. We then present a number of equations and inequalities in these invariants; in particular, we give a higher-order generalization of the shadow enumerator of a code, and prove that its coefficients are nonnegative. We also prove that the quartic invariants of a ((4,4,2)) are uniquely determined, an important step in a proof that any ((4,4,2)) is additive ([2]).
Tractors, Mass and Weyl Invariance
Gover, A R; Waldron, A
2008-01-01
Deser and Nepomechie established a relationship between masslessness and rigid conformal invariance by coupling to a background metric and demanding local Weyl invariance, a method which applies neither to massive theories nor theories which rely upon gauge invariances for masslessness. We extend this method to describe massive and gauge invariant theories using Weyl invariance. The key idea is to introduce a new scalar field which is constant when evaluated at the scale corresponding to the metric of physical interest. This technique relies on being able to efficiently construct Weyl invariant theories. This is achieved using tractor calculus--a mathematical machinery designed for the study of conformal geometry. From a physics standpoint, this amounts to arranging fields in multiplets with respect to the conformal group but with novel Weyl transformation laws. Our approach gives a mechanism for generating masses from Weyl weights. Breitenlohner--Freedman stability bounds for Anti de Sitter theories arise na...
Factorization invariants in numerical monoids
O'Neill, Christopher; Pelayo, Roberto
2015-01-01
Nonunique factorization in commutative monoids is often studied using factorization invariants, which assign to each monoid element a quantity determined by the factorization structure. For numerical monoids (co-finite, additive submonoids of the natural numbers), several factorization invariants have received much attention in the recent literature. In this survey article, we give an overview of the length set, elasticity, delta set, $\\omega$-primality, and catenary degree invariants in the ...
Invariants and Likelihood Ratio Statistics
McCullagh, P.; Cox, D. R.
1986-01-01
Because the likelihood ratio statistic is invariant under reparameterization, it is possible to make a large-sample expansion of the statistic itself and of its expectation in terms of invariants. In particular, the Bartlett adjustment factor can be expressed in terms of invariant combinations of cumulants of the first two log-likelihood derivatives. Such expansions are given, first for a scalar parameter and then for vector parameters. Geometrical interpretation is given where possible and s...
The Asymmetric Leximin Solution
Driesen, Bram W.
2012-01-01
In this article we define and characterize a class of asymmetric leximin solutions, that contains both the symmetric leximin solution of Imai[5] and the two-person asymmetric Kalai-Smorodinsky solution of Dubra [3] as special cases. Solutions in this class combine three attractive features: they are defined on the entire domain of convex n-person bargaining problems, they generally yield Pareto efficient solution outcomes, and asymmetries among bargainers are captured by a single parameter ve...
Graesser, Michael L.; Shoemaker, Ian M.; Vecchi, Luca
2011-01-01
In existing dark matter models with global symmetries the relic abundance of dark matter is either equal to that of anti-dark matter (thermal WIMP), or vastly larger, with essentially no remaining anti-dark matter (asymmetric dark matter). By exploring the consequences of a primordial asymmetry on the coupled dark matter and anti-dark matter Boltzmann equations we find large regions of parameter space that interpolate between these two extremes. Interestingly, this new asymmetric WIMP framewo...
Tractors, mass, and Weyl invariance
Gover, A. R.; Shaukat, A.; Waldron, A.
2009-05-01
Deser and Nepomechie established a relationship between masslessness and rigid conformal invariance by coupling to a background metric and demanding local Weyl invariance, a method which applies neither to massive theories nor theories which rely upon gauge invariances for masslessness. We extend this method to describe massive and gauge invariant theories using Weyl invariance. The key idea is to introduce a new scalar field which is constant when evaluated at the scale corresponding to the metric of physical interest. This technique relies on being able to efficiently construct Weyl invariant theories. This is achieved using tractor calculus—a mathematical machinery designed for the study of conformal geometry. From a physics standpoint, this amounts to arranging fields in multiplets with respect to the conformal group but with novel Weyl transformation laws. Our approach gives a mechanism for generating masses from Weyl weights. Breitenlohner-Freedman stability bounds for Anti-de Sitter theories arise naturally as do direct derivations of the novel Weyl invariant theories given by Deser and Nepomechie. In constant curvature spaces, partially massless theories—which rely on the interplay between mass and gauge invariance—are also generated by our method. Another simple consequence is conformal invariance of the maximal depth partially massless theories. Detailed examples for spins s⩽2 are given including tractor and component actions, on-shell and off-shell approaches and gauge invariances. For all spins s⩾2 we give tractor equations of motion unifying massive, massless, and partially massless theories.
Topological invariants in magnetic hydrodynaics
A definition of force line reconnection is proposed within the framework of the ideal hydrodynamics (Rem > 1). It detailizes some previous results. On the basis of the definition it is proved that the asymptotic Hopf invariant is conserved within a time interval τ which is much smaller than the skin (diffusion) time τd. Generally speaking there are no other invariants characterizing a magnetic field configuration (in simply-connected domains). For smooth flow of an ideally conducting fluid (Rem=∞) a method is proposed for determining the linked force line invariants which differ from the Hopf invariant
Conformal Invariant Teleparallel Cosmology
Momeni, Davood
2014-01-01
Teleparallel gravities revisited under conformal transformations. We find several kinds of the Lagrangians, all invariant under conformal transformation. Motivated by observational data,we investigate FRW cosmological solutions in the vacuum. To include the matter fields,we mention that we have few possibilities for our matter Lagrangian to respect the conformal symmetry. FRW equations,have been derived in terms of the effective energy and pressure components. In vacuum we find an exact solution for Hubble parameter which is compatible with the observational data but it is valid only in the range of $z\\ge 0.07$. Scalar torsion models in which we have the extra scalar field is examined under FRW spacetime. We introduce the potential term $\\frac{1}{4!}\\mu\\phi^4$ as the minimal self interaction with conformal symmetry.
Lorentz invariant intrinsic decoherence
Milburn, G J
2003-01-01
Quantum decoherence can arise due to classical fluctuations in the parameters which define the dynamics of the system. In this case decoherence, and complementary noise, is manifest when data from repeated measurement trials are combined. Recently a number of authors have suggested that fluctuations in the space-time metric arising from quantum gravity effects would correspond to a source of intrinsic noise, which would necessarily be accompanied by intrinsic decoherence. This work extends a previous heuristic modification of Schr\\"{o}dinger dynamics based on discrete time intervals with an intrinsic uncertainty. The extension uses unital semigroup representations of space and time translations rather than the more usual unitary representation, and does the least violence to physically important invariance principles. Physical consequences include a modification of the uncertainty principle and a modification of field dispersion relations, in a way consistent with other modifications suggested by quantum grav...
Invariants of Lagrangian surfaces
Yau, Mei-Lin
2004-01-01
We define a nonnegative integer $\\la(L,L_0;\\phi)$ for a pair of diffeomorphic closed Lagrangian surfaces $L_0,L$ embedded in a symplectic 4-manifold $(M,\\w)$ and a diffeomorphism $\\phi\\in\\Diff^+(M)$ satisfying $\\phi(L_0)=L$. We prove that if there exists $\\phi\\in\\Diff^+_o(M)$ with $\\phi(L_0)=L$ and $\\la(L,L_0;\\phi)=0$, then $L_0,L$ are symplectomorphic. We also define a second invariant $n(L_1,L_0;[L_t])=n(L_1,L_0,[\\phi_t])$ for a smooth isotopy $L_t=\\phi_t(L_0)$ between two Lagrangian surfac...
Reweighting with Boosted Decision Trees
Rogozhnikov, A
2016-01-01
Machine learning tools are commonly used in modern high energy physics (HEP) experiments. Different models, such as boosted decision trees (BDT) and artificial neural networks (ANN), are widely used in analyses and even in the software triggers. In most cases, these are classification models used to select the "signal" events from data. Monte Carlo simulated events typically take part in training of these models. While the results of the simulation are expected to be close to real data, in practical cases there is notable disagreement between simulated and observed data. In order to use available simulation in training, corrections must be introduced to generated data. One common approach is reweighting - assigning weights to the simulated events. We present a novel method of event reweighting based on boosted decision trees. The problem of checking the quality of reweighting step in analyses is also discussed.
Boosting Infrastructure Investments in Africa
Donald Kaberuka
2011-01-01
The absolute and relative lack of infrastructure in Africa suggests that the continentâ€™s competitiveness could be boosted by scaling up investments in infrastructure. Such investments would facilitate domestic and international trade, enhance Africaâ€™s integration into the global economy and promote better human development outcomes, especially, by bringing unconnected rural communities into the mainstream economy. While there are yawning gaps in all infrastructure subsectors, inadequate e...
Asymmetric Dark Matter Models and the LHC Diphoton Excess
Frandsen, Mads T.; Shoemaker, Ian M.
2016-01-01
The existence of dark matter (DM) and the origin of the baryon asymmetry are persistent indications that the SM is incomplete. More recently, the ATLAS and CMS experiments have observed an excess of diphoton events with invariant mass of about 750 GeV. One interpretation of this excess is decays...... have for models of asymmetric DM that attempt to account for the similarity of the dark and visible matter abundances....
Let ZLMO be the 3-manifold invariant of [LMO]. It is shown that ZLMO(M) = 1, if the first Betti number of M, b1 (M), is greater than 3. If b1 (M) = 3, then ZLMO (M) is completely determined by the cohomology ring of M. A relation of ZLMO with the Rozansky-Witten invariants ZXRW[M] is established at a physical level of rigour. We show that ZXRW[M] satisfies appropriate connected sum properties suggesting that the generalized Casson invariant ought to be computable from the LMO invariant. (author)
Chiral Invariance of Massive Fermions
Das, A.(University of Arizona, Tucson, AZ, 85721, USA); Hott, M
1994-01-01
We show that a massive fermion theory, while not invariant under the conventional chiral transformation, is invariant under a $m$-deformed chiral transformation. These transformations and the associated conserved charges are nonlocal but reduce to the usual transformations and charges when $m=0$. The $m$-deformed charges commute with helicity and satisfy the conventional chiral algebra.
Reducing Lookups for Invariant Checking
Thomsen, Jakob Grauenkjær; Clausen, Christian; Andersen, Kristoffer Just;
2013-01-01
satisfied. We present a formal model of this scenario, based on a simple query language for the expression of invariants that covers the core of a realistic query language. We present an algorithm which simplifies a representation of the invariant, along with a mechanically verified proof of correctness. We...
Multilocal invariants for the classical groups
Paul F. Dhooghe
2003-01-01
Full Text Available Multilocal higher-order invariants, which are higher-order invariants defined at distinct points of representation space, for the classical groups are derived in a systematic way. The basic invariants for the classical groups are the well-known polynomial or rational invariants as derived from the Capelli identities. Higher-order invariants are then constructed from the former ones by means of total derivatives. At each order, it appears that the invariants obtained in this way do not generate all invariants. The necessary additional invariants are constructed from the invariant polynomials on the Lie algebra of the Lie transformation groups.
Fayngold, Moses
2010-01-01
A careful look at an allegedly well-known century-old concept reveals interesting aspects in it that have generally avoided recognition in literature. There are four different kinds of physical observables known or proclaimed as relativistic invariants under space-time rotations. Only observables in the first three categories are authentic invariants, whereas the single "invariant" - proper length - in the fourth category is actually not an invariant. The proper length has little is anything to do with proper distance which is a true invariant. On the other hand, proper distance, proper time, and rest mass have more in common than usually recognized, and particularly, mass - time analogy opens another view of the twin paradox.
Invariant Measures for Cherry Flows
Saghin, Radu; Vargas, Edson
2013-01-01
We investigate the invariant probability measures for Cherry flows, i.e. flows on the two-torus which have a saddle, a source, and no other fixed points, closed orbits or homoclinic orbits. In the case when the saddle is dissipative or conservative we show that the only invariant probability measures are the Dirac measures at the two fixed points, and the Dirac measure at the saddle is the physical measure. In the other case we prove that there exists also an invariant probability measure supported on the quasi-minimal set, we discuss some situations when this other invariant measure is the physical measure, and conjecture that this is always the case. The main techniques used are the study of the integrability of the return time with respect to the invariant measure of the return map to a closed transversal to the flow, and the study of the close returns near the saddle.
Hidden scale invariance of metals
Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.;
2015-01-01
of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were......Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general “hidden” scale invariance...... available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant...
Study of an asymmetric B-factory
A facility in which e+ - e- beams collide with different beam energies (Eel/Epos > 3) would provide the possibility of measuring CP violation and rare decays in the B-quark system. Luminosities of several 1033 cm-2s-1 are required. In this paper the authors report on a study in which the use of the PETRA storage ring for such a facility is investigated. The basic concept is to exploit the existence of a large storage ring. This allows one to operate the asymmetric collider near the optimum Lorentz boost for the detection of the decay vertices of the B-mesons, namely βγ = 1. Beam energies of 12 GeV for the electrons and 2.33 GeV for the positrons stored in a 144-m-circumference ring appear to be the best compromise between optimum Lorentz boost, high luminosity, and tolerable synchrotron radiation power losses. The main factors in attaining high luminosity are the high multibunch beam currents in both beams, high single bunch currents in the low-energy beam, operation with many bunches requiring quick beam separation, strong low-β focusing, synchrotron radiation generated in the beam separators, and finally large total synchrotron radiation power loss of the beam. Practical solutions using currently available accelerator technology are discussed in this report
Csaki, Csaba; Erlich, Joshua; Grojean, Christophe
2000-01-01
We investigate spacetimes in which the speed of light along flat 4D sections varies over the extra dimensions due to different warp factors for the space and the time coordinates (``asymmetrically warped'' spacetimes). The main property of such spaces is that while the induced metric is flat, implying Lorentz invariant particle physics on a brane, bulk gravitational effects will cause apparent violations of Lorentz invariance and of causality from the brane observer's point of view. An import...
Physical Invariants of Intelligence
Zak, Michail
2010-01-01
A program of research is dedicated to development of a mathematical formalism that could provide, among other things, means by which living systems could be distinguished from non-living ones. A major issue that arises in this research is the following question: What invariants of mathematical models of the physics of systems are (1) characteristic of the behaviors of intelligent living systems and (2) do not depend on specific features of material compositions heretofore considered to be characteristic of life? This research at earlier stages has been reported, albeit from different perspectives, in numerous previous NASA Tech Briefs articles. To recapitulate: One of the main underlying ideas is to extend the application of physical first principles to the behaviors of living systems. Mathematical models of motor dynamics are used to simulate the observable physical behaviors of systems or objects of interest, and models of mental dynamics are used to represent the evolution of the corresponding knowledge bases. For a given system, the knowledge base is modeled in the form of probability distributions and the mental dynamics is represented by models of the evolution of the probability densities or, equivalently, models of flows of information. At the time of reporting the information for this article, the focus of this research was upon the following aspects of the formalism: Intelligence is considered to be a means by which a living system preserves itself and improves its ability to survive and is further considered to manifest itself in feedback from the mental dynamics to the motor dynamics. Because of the feedback from the mental dynamics, the motor dynamics attains quantum-like properties: The trajectory of the physical aspect of the system in the space of dynamical variables splits into a family of different trajectories, and each of those trajectories can be chosen with a probability prescribed by the mental dynamics. From a slightly different perspective
Top-tagging: A Method for Identifying Boosted Hadronic Tops
Kaplan, David E; Schwartz, Matthew D; Tweedie, Brock
2008-01-01
A method is introduced for distinguishing top jets -- boosted, hadronically decaying top quarks -- from standard model backgrounds using jet substructure. The procedure involves parsing the jet cluster to resolve features such as three light quark subjets, and then imposing angular and kinematic constraints. This method is much more efficient than simple invariant mass cuts or jet clustering with fixed angular size. With top-tagging, high pT dijets can be rejected with an efficiency of around 99% while retaining 20-40% of the tops. This allows us to reach into the all-hadronic channel for new-physics signals, such as new heavy t-tbar resonances, which ordinarily would be overwhelmed by the enormous dijet background. In addition, it will improve the reach for cases when one of the tops decays semi-leptonically, and may also have applications to single-top searches and studies of b-tagging efficiency at high pT.
An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode is disclosed. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity. 4 figs
Duality and Data Dependence in Boosting /
Telgarsky, Matus
2013-01-01
Boosting algorithms produce accurate predictors for complex phenomena by welding together collections of simple predictors. In the classical method AdaBoost, as well as its immediate variants, the welding points are determined by convex optimization; unlike typical applications of convex optimization in machine learning, however, the AdaBoost scheme eschews the usual regularization and constraints used to control numerical and statistical properties. On the other hand, the data and simple pre...
Positive Semidefinite Metric Learning with Boosting
Shen, Chunhua; Kim, Junae; Wang, Lei; Hengel, Anton van den
2009-01-01
The learning of appropriate distance metrics is a critical problem in image classification and retrieval. In this work, we propose a boosting-based technique, termed \\BoostMetric, for learning a Mahalanobis distance metric. One of the primary difficulties in learning such a metric is to ensure that the Mahalanobis matrix remains positive semidefinite. Semidefinite programming is sometimes used to enforce this constraint, but does not scale well. \\BoostMetric is instead based on a key observat...
Adaptive Sampling for Large Scale Boosting
Dubout, Charles; Fleuret, Francois
2014-01-01
Classical Boosting algorithms, such as AdaBoost, build a strong classifier without concern for the computational cost. Some applications, in particular in computer vision, may involve millions of training examples and very large feature spaces. In such contexts, the training time of off-the-shelf Boosting algorithms may become prohibitive. Several methods exist to accelerate training, typically either by sampling the features or the examples used to train the weak learners. Even if some of th...
Where boosted significances come from
Plehn, Tilman; Schichtel, Peter; Wiegand, Daniel
2014-03-01
In an era of increasingly advanced experimental analysis techniques it is crucial to understand which phase space regions contribute a signal extraction from backgrounds. Based on the Neyman-Pearson lemma we compute the maximum significance for a signal extraction as an integral over phase space regions. We then study to what degree boosted Higgs strategies benefit ZH and tt¯H searches and which transverse momenta of the Higgs are most promising. We find that Higgs and top taggers are the appropriate tools, but would profit from a targeted optimization towards smaller transverse momenta. MadMax is available as an add-on to MadGraph 5.
Gauge-invariant formulation of SU(2) gluodynamics
The internal structure of a double asymmetric rotator is revealed in vector potential Asub(μa) via a proposed polar representation (PR). In the functional integral a natural gauge choice exists in PR not accompanied by Faddeev-Popov ghosts and Gribov ambiguities. Classical equations in PR are written in terms of only gauge invariant quantities. Instantons and magnetic monopoles in the Bogolmolny-Prasad-Sommerfield limit as well as the color-magnetic field of the 'tHooft-Polyakov monopole are studied in PR
Invariant manifolds and global bifurcations.
Guckenheimer, John; Krauskopf, Bernd; Osinga, Hinke M; Sandstede, Björn
2015-09-01
Invariant manifolds are key objects in describing how trajectories partition the phase spaces of a dynamical system. Examples include stable, unstable, and center manifolds of equilibria and periodic orbits, quasiperiodic invariant tori, and slow manifolds of systems with multiple timescales. Changes in these objects and their intersections with variation of system parameters give rise to global bifurcations. Bifurcation manifolds in the parameter spaces of multi-parameter families of dynamical systems also play a prominent role in dynamical systems theory. Much progress has been made in developing theory and computational methods for invariant manifolds during the past 25 years. This article highlights some of these achievements and remaining open problems. PMID:26428557
Invariants of Toric Seiberg Duality
Hanany, Amihay; Jejjala, Vishnu; Pasukonis, Jurgis; Ramgoolam, Sanjaye; Rodriguez-Gomez, Diego
2011-01-01
Three-branes at a given toric Calabi-Yau singularity lead to different phases of the conformal field theory related by toric (Seiberg) duality. Using the dimer model/brane tiling description in terms of bipartite graphs on a torus, we find a new invariant under Seiberg duality, namely the Klein j-invariant of the complex structure parameter in the distinguished isoradial embedding of the dimer, determined by the physical R-charges. Additional number theoretic invariants are described in terms of the algebraic number field of the R-charges. We also give a new compact description of the a-maximization procedure by introducing a generalized incidence matrix.
Invariant and semi-invariant probabilistic normed spaces
Ghaemi, M.B. [School of Mathematics Iran, University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of)], E-mail: mghaemi@iust.ac.ir; Lafuerza-Guillen, B. [Departamento de Estadistica y Matematica Aplicada, Universidad de Almeria, Almeria E-04120 (Spain)], E-mail: blafuerz@ual.es; Saiedinezhad, S. [School of Mathematics Iran, University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of)], E-mail: ssaiedinezhad@yahoo.com
2009-10-15
Probabilistic metric spaces were introduced by Karl Menger. Alsina, Schweizer and Sklar gave a general definition of probabilistic normed space based on the definition of Menger . We introduce the concept of semi-invariance among the PN spaces. In this paper we will find a sufficient condition for some PN spaces to be semi-invariant. We will show that PN spaces are normal spaces. Urysohn's lemma, and Tietze extension theorem for them are proved.
Control of Wind Turbines during Symmetrical and Asymmetrical Grid Faults
Göksu, Ömer
grid code requirements, which are targeting to make the WPPs operate in a closer manner to the conventional power plants. Common to most of the grid codes, WPPs are required to stay connected during short-circuit grid faults, and also inject reactive current in order to support the grid voltage...... type wind turbines (WTs), in an AC connected WPP, is investigated and control algorithms are designed for minimum disrupted operation and improved grid support, for both symmetrical and asymmetrical grid faults. WTs’ response with conventional control algorithms is studied regarding the impact...... in accordance with the grid code requirement, positive sequence grid voltage is boosted, but negative sequence grid voltage also is also boosted due to the coupling. As a result higher overvoltages at the non-faulty phases occur. In this thesis an alternative injection method, where WTs are injecting both...
Recursive bias estimation and L2 boosting
Hengartner, Nicolas W [Los Alamos National Laboratory; Cornillon, Pierre - Andre [INRA, FRANCE; Matzner - Lober, Eric [RENNE, FRANCE
2009-01-01
This paper presents a general iterative bias correction procedure for regression smoothers. This bias reduction schema is shown to correspond operationally to the L{sub 2} Boosting algorithm and provides a new statistical interpretation for L{sub 2} Boosting. We analyze the behavior of the Boosting algorithm applied to common smoothers S which we show depend on the spectrum of I - S. We present examples of common smoother for which Boosting generates a divergent sequence. The statistical interpretation suggest combining algorithm with an appropriate stopping rule for the iterative procedure. Finally we illustrate the practical finite sample performances of the iterative smoother via a simulation study.
Villamizar, Michael; Sanfeliu, Alberto; Andrade-Cetto, J.
2006-01-01
We present a framework for object detection that is invariant to object translation, scale, rotation, and to some degree, occlusion, achieving high detection rates, at 14 fps in color images and at 30 fps in gray scale images. Our approach is based on boosting over a set of simple local features. In contrast to previous approaches, and to efficiently cope with orientation changes, we propose the use of non-Gaussian steerable filters, together with a new orientation integral image for a speedy...
Gauge-invariant formulation of the dynamics of the quantized Yang--Mills field
The quantum theory of the Yang--Mills field is formulated in terms of gauge-invariant, path-independent potentials and conjugate momenta. These nonlocal variables are a generalization to the non-Abelian case of the gauge invariants used by Dirac in his gauge-invariant formulation of quantum electrodynamics, and they are a path-independent, symmetrically ordered modification of the Mandelstam-displaced operators. The commutation relations, constraints, and equations of motion satisfied by the gauge invariants are derived from a canonical foundation and are seen to form Schwinger's consistent system of symmetrically factor-ordered gauge-field equations. All equations are satisfied strongly, and, if gauge-invariant operators are used to raise states from a gauge-invariant vacuum, nonphysical states will not be introduced into the theory. A simple relation holds between the local, canonical variables and the gauge invariants; this circumstance allows the energy--momentum tensor density to be expressed either in terms of the canonical variables or the gauge invariants. Elimination of the local canonical variables in favor of the gauge invariants shows, from a different point of view, the origin of the nonclassical terms in Schwinger's Hamiltonian and equations of motion. It is shown that these terms are necessary in order to satisfy integrability conditions on the field equations. Working with the canonical variables permits a straightforward evaluation of the energy--momentum density commutators which are needed to verify the Lie-algebra relations of the inhomogeneous Lorentz group and the local conservation of the energy--momentum density operator. The inhomogeneous Lorentz-group boost-transformation equations are derived in a manner natural to the development given here. Schwinger's transformations are found and his assertion of Lorentz invariance is confirmed
Asymmetric reactions in continuous flow
Xiao Yin Mak
2009-04-01
Full Text Available An overview of asymmetric synthesis in continuous flow and microreactors is presented in this review. Applications of homogeneous and heterogeneous asymmetric catalysis as well as biocatalysis in flow are discussed.
Local Scale Invariance and Inflation
Singh, Naveen K
2016-01-01
We study the inflation and the cosmological perturbations generated during the inflation in a local scale invariant model. The local scale invariant model introduces a vector field $S_{\\mu}$ in this theory. In this paper, for simplicity, we consider the temporal part of the vector field $S_t$. We show that the temporal part is associated with the slow roll parameter of scalar field. Due to local scale invariance, we have a gauge degree of freedom. In a particular gauge, we show that the local scale invariance provides sufficient number of e-foldings for the inflation. Finally, we estimate the power spectrum of scalar perturbation in terms of the parameters of the theory.
Invariant measures for Cherry flows
Saghin, Radu
2011-01-01
We investigate the invariant probability measures for Cherry flows, i.e. flows on the two-torus which have a saddle, a source, and no other fixed points, closed orbits or homoclinic orbits. In the case when the saddle is dissipative or conservative we show that the only invariant probability measures are the Dirac measures at the two fixed points, and the Dirac measure at the saddle is the physical measure. In the other case we discuss some situations when there exists another invariant measure supported on the quasi-minimal set, which is the physical measure, and conjecture that this is always the case. The main techniques used are the study of the integrability of the return time with respect to the invariant measure of the return map to a closed transversal to the flow, and the study of the close returns near the saddle.
Scaling Equation for Invariant Measure
LIU Shi-Kuo; FU Zun-Tao; LIU Shi-Da; REN Kui
2003-01-01
An iterated function system (IFS) is constructed. It is shown that the invariant measure of IFS satisfies the same equation as scaling equation for wavelet transform (WT). Obviously, IFS and scaling equation of WT both have contraction mapping principle.
Moment Invariants for Object Recognition
Flusser, Jan
Boca Raton: Wiley&Sons, 2015. ISBN 9780471346081 Institutional support: RVO:67985556 Keywords : invariants * object recognition * moments Subject RIV: JC - Computer Hardware ; Software http://library.utia.cas.cz/separaty/2015/ZOI/flusser-0442976.pdf
Invariant measures in brain dynamics
This note concerns brain activity at the level of neural ensembles and uses ideas from ergodic dynamical systems to model and characterize chaotic patterns among these ensembles during conscious mental activity. Central to our model is the definition of a space of neural ensembles and the assumption of discrete time ensemble dynamics. We argue that continuous invariant measures draw the attention of deeper brain processes, engendering emergent properties such as consciousness. Invariant measures supported on a finite set of ensembles reflect periodic behavior, whereas the existence of continuous invariant measures reflect the dynamics of nonrepeating ensemble patterns that elicit the interest of deeper mental processes. We shall consider two different ways to achieve continuous invariant measures on the space of neural ensembles: (1) via quantum jitters, and (2) via sensory input accompanied by inner thought processes which engender a 'folding' property on the space of ensembles
Object recognition by implicit invariants
Flusser, Jan; Kautsky, J.; Šroubek, Filip
2007-01-01
Roč. 2007, č. 4673 (2007), s. 856-863. ISSN 0302-9743. [Computer Analysis of Images and Patterns. Vienna, 27.08.2007-29.08.2007] R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : Invariants * implicit invariants * moments * orthogonal polynomials * nonlinear object deformation Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.402, year: 2005 http:// staff .utia.cas.cz/sroubekf/papers/CAIP_07.pdf
Current forms and gauge invariance
Let C be the bundle of connections of a principal G-bundle π:P → M, and let V be the vector bundle associated with P by a linear representation G → GL(V) on a finite-dimensional vector space V. The Lagrangians on J1(C x MV) whose current form is gauge invariant, are described and the gauge-invariant Lagrangians on J1(V) are classified
Gauge invariance and lattice monopoles
The number and the location of monopoles in Lattice configurations depend on the choice of the gauge, in contrast to the obvious requirement that monopoles, as physical objects, have a gauge-invariant status. It is proved, starting from non-abelian Bianchi identities, that monopoles are indeed gauge-invariant: the technique used to detect them has instead an efficiency which depends on the choice of the abelian projection, in a known and well understood way.
Classification of Simple Current Invariants
Gato-Rivera, Beatriz
1991-01-01
We summarize recent work on the classification of modular invariant partition functions that can be obtained with simple currents in theories with a center (Z_p)^k with p prime. New empirical results for other centers are also presented. Our observation that the total number of invariants is monodromy-independent for (Z_p)^k appears to be true in general as well. (Talk presented in the parallel session on string theory of the Lepton-Photon/EPS Conference, Geneva, 1991.)
Modern Tests of Lorentz Invariance
Mattingly David
2005-09-01
Full Text Available Motivated by ideas about quantum gravity, a tremendous amount of effort over the past decade has gone into testing Lorentz invariance in various regimes. This review summarizes both the theoretical frameworks for tests of Lorentz invariance and experimental advances that have made new high precision tests possible. The current constraints on Lorentz violating effects from both terrestrial experiments and astrophysical observations are presented.
Hidden scale invariance of metals
Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.; Pedersen, Ulf R.
2015-11-01
Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general "hidden" scale invariance of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant inverse power-law (IPL) pair interactions. However, crystal packings of several transition metals (V, Cr, Mn, Fe, Nb, Mo, Ta, W, and Hg), most post-transition metals (Ga, In, Sn, and Tl), and the metalloids Si and Ge cannot be explained by the IPL assumption. The virial-energy correlation coefficients of iron and phosphorous are shown to increase at elevated pressures. Finally, we discuss how scale invariance explains the Grüneisen equation of state and a number of well-known empirical melting and freezing rules.
RBOOST: RIEMANNIAN DISTANCE BASED REGULARIZED BOOSTING.
Liu, Meizhu; Vemuri, Baba C
2011-03-30
Boosting is a versatile machine learning technique that has numerous applications including but not limited to image processing, computer vision, data mining etc. It is based on the premise that the classification performance of a set of weak learners can be boosted by some weighted combination of them. There have been a number of boosting methods proposed in the literature, such as the AdaBoost, LPBoost, SoftBoost and their variations. However, the learning update strategies used in these methods usually lead to overfitting and instabilities in the classification accuracy. Improved boosting methods via regularization can overcome such difficulties. In this paper, we propose a Riemannian distance regularized LPBoost, dubbed RBoost. RBoost uses Riemannian distance between two square-root densities (in closed form) - used to represent the distribution over the training data and the classification error respectively - to regularize the error distribution in an iterative update formula. Since this distance is in closed form, RBoost requires much less computational cost compared to other regularized Boosting algorithms. We present several experimental results depicting the performance of our algorithm in comparison to recently published methods, LP-Boost and CAVIAR, on a variety of datasets including the publicly available OASIS database, a home grown Epilepsy database and the well known UCI repository. Results depict that the RBoost algorithm performs better than the competing methods in terms of accuracy and efficiency. PMID:21927643
Rotation invariant moments and transforms for geometrically invariant image watermarking
Singh, Chandan; Ranade, Sukhjeet K.
2013-01-01
We present invariant image watermarking based on a recently introduced set of polar harmonic transforms and angular radial transforms and their comparative analysis with state-of-art approaches based on Zernike moments and pseudo-Zernike moments (ZMs/PZMs). Similar to ZMs/PZMs, these transforms provide rotation invariance and resilience to noise while mitigating inherent limitations like numerical instability and computational cost at high order of moments. These characteristics motivate us to design invariant transform-based invariant image watermarking schemes that can withstand various intentional or unintentional attacks, handle large bitcarriers, and work in a limited computing environment. A comparative performance evaluation of watermarking systems regarding critical parameters like visual imperceptibility, embedding capacity, and watermark robustness against geometric transformations, common signal processing distortions, and Stirmark attacks is performed along with the empirical analysis of various inherent properties of transforms and moments such as magnitude invariance, reconstruction capabilities, and computational complexity to investigate relationships between the performance of watermarking schemes and inherent properties of transforms.
Boosting as a Product of Experts
Edakunni, Narayanan U; Kovacs, Tim
2012-01-01
In this paper, we derive a novel probabilistic model of boosting as a Product of Experts. We re-derive the boosting algorithm as a greedy incremental model selection procedure which ensures that addition of new experts to the ensemble does not decrease the likelihood of the data. These learning rules lead to a generic boosting algorithm - POE- Boost which turns out to be similar to the AdaBoost algorithm under certain assumptions on the expert probabilities. The paper then extends the POEBoost algorithm to POEBoost.CS which handles hypothesis that produce probabilistic predictions. This new algorithm is shown to have better generalization performance compared to other state of the art algorithms.
Exponential decay and ergodicity of completely asymmetric Lévy processes in a finite interval
Bertoin, Jean
1997-01-01
Consider a completely asymmetric Lévy process which has absolutely continuous transition probabilities. We determine the exponential decay parameter $\\rho$ and the quasistationary distribution for the transition probabilities of the Lévy process killed as it exits from a finite interval, prove that the killed process is $\\rho$-positive and specify the $\\rho$-invariant function and measure.
Abubakkar Siddik A
2012-06-01
Full Text Available Increasing in power demand and shortage of conventional energy sources, researchers are focused on renewable energy. The proposed solar power generation circuit consists of solar array, boost converter and boost inverter. Low voltage, of photovoltaic array, is boosted using dc-dc boost converter to charge the battery and boost inverter convert this battery voltage to high quality sinusoidal ac voltage. The output of solar power fed from boost inverter feed to autonomous load without any intermediate conversion stage and a filter. For boost converter operation duty cycle is varied through fuzzy logic controller and PWM block to regulate the converter output voltage. The ac voltage total harmonic distortion (THD obtained using this configuration is quite acceptable. The proposed power generation system has several desirable features such as low cost and compact size as number of switches used, are limited to four as against six switches used in classical two-stage inverters.
Advanced Airfoils Boost Helicopter Performance
2007-01-01
Carson Helicopters Inc. licensed the Langley RC4 series of airfoils in 1993 to develop a replacement main rotor blade for their Sikorsky S-61 helicopters. The company's fleet of S-61 helicopters has been rebuilt to include Langley's patented airfoil design, and the helicopters are now able to carry heavier loads and fly faster and farther, and the main rotor blades have twice the previous service life. In aerial firefighting, the performance-boosting airfoils have helped the U.S. Department of Agriculture's Forest Service control the spread of wildfires. In 2003, Carson Helicopters signed a contract with Ducommun AeroStructures Inc., to manufacture the composite blades for Carson Helicopters to sell
ATLAS boosted object tagging 2
Caudron, Julien; The ATLAS collaboration
2015-01-01
A detailed study into the optimal techniques for identifying boosted hadronically decaying W or Z bosons is presented. Various algorithms for reconstructing, grooming and tagging bosonic jets are compared for W bosons with a wide range of transverse momenta using 8 TeV data and 8 TeV and 13 TeV MC simulations. In addition, given that a hadronic jet has been identified as resulting from the hadronic decay of a W or Z, a technique is developed to discriminate between W and Z bosons. The modeling of the tagging variables used in this technique is studied using 8 TeV pp collision data and systematic uncertainties for the tagger efficiency and fake rates are evaluated.
Local Unitary Invariants for Multipartite Quantum Systems
Wang, Jing; Li, Ming; Fei, Shao-Ming; Li-Jost, Xianqing
2014-01-01
We present an approach of constructing invariants under local unitary transformations for multipartite quantum systems. The invariants constructed in this way can be complement to that in [Science 340 (2013) 1205-1208]. Detailed examples are given to compute such invariant in detail. It is shown that these invariants can be used to detect the local unitary equivalence of degenerated quantum states.
Weyl invariance with a nontrivial mass scale
Alvarez, Enrique
2016-01-01
A theory with a mass scale and yet Weyl invariant is presented. The theory is not invariant under all diffeomorphisms but only under transverse ones. This is the reason why Weyl invariance does not imply scale invariance in a free falling frame. Physical implications of this framework are discussed.
Asymmetric information and economics
Frieden, B. Roy; Hawkins, Raymond J.
2010-01-01
We present an expression of the economic concept of asymmetric information with which it is possible to derive the dynamical laws of an economy. To illustrate the utility of this approach we show how the assumption of optimal information flow leads to a general class of investment strategies including the well-known Q theory of Tobin. Novel consequences of this formalism include a natural definition of market efficiency and an uncertainty principle relating capital stock and investment flow.
Asymmetric Organocatalytic Cycloadditions
Mose, Rasmus
2016-01-01
were pioneered by Otto Paul Hermann Diels and Kurt Alder who discovered what later became known as the Diels Alder reaction. The Diels Alder reaction is a [4+2] cycloaddition in which a π4 component reacts with a π2 component via a cyclic transition state to generate a 6 membered ring. This reaction...... reactions constitute the first organocatalytic asymmetric higher order cycloadditions and a rational for the periselectivity and stereoselectivity is provided based on experimental and computational investigations....
Asymmetric Parton Distributions
Radyushkin, A V
1997-01-01
Applications of perturbative QCD to hard exclusive electroproduction processes in the Bjorken limit at small invariant momentum transfer t bring in a new type of parton distributions which have hybrid properties, resembling both the parton distribution functions and the distribution amplitudes. Their t-dependence is analogous to that of hadronic form factors. We discuss general properties of these new parton distributions, their relation to usual parton densities and the evolution equations which they satisfy.
Asymmetric extractions in orthodontics
Camilo Aquino Melgaço
2012-04-01
Full Text Available INTRODUCTION: Extraction decisions are extremely important in during treatment planning. In addition to the extraction decision orthodontists have to choose what tooth should be extracted for the best solution of the problem and the esthetic/functional benefit of the patient. OBJECTIVE: This article aims at reviewing the literature relating the advantages, disadvantages and clinical implications of asymmetric extractions to orthodontics. METHODS: Keywords were selected in English and Portuguese and the EndNote 9 program was used for data base search in PubMed, Web of Science (WSc and LILACS. The selected articles were case reports, original articles and prospective or retrospective case-control studies concerning asymmetrical extractions of permanent teeth for the treatment of malocclusions. CONCLUSION: According to the literature reviewed asymmetric extractions can make some specific treatment mechanics easier. Cases finished with first permanent molars in Class II or III relationship in one or both sides seem not to cause esthetic or functional problems. However, diagnosis knowledge and mechanics control are essential for treatment success.
Asymmetric Evolutionary Games.
McAvoy, Alex; Hauert, Christoph
2015-08-01
Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner's Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games. PMID:26308326
Orthodontics Align Crooked Teeth and Boost Self-Esteem
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Geometric invariance of mass-like asymptotic invariants
Michel, Benoît
2010-01-01
We study coordinate-invariance of some asymptotic invariants such as the ADM mass or the Chru\\'sciel-Herzlich momentum, given by an integral over a "boundary at infinity". When changing the coordinates at infinity, some terms in the change of integrand do not decay fast enough to have a vanishing integral at infinity; but they may be gathered in a divergence, thus having vanishing integral over any closed hypersurface. This fact could only be checked after direct calculation (and was called a...
Fission dynamics within time-dependent Hartree-Fock. II. Boost-induced fission
Goddard, Philip; Stevenson, Paul; Rios, Arnau
2016-01-01
Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of fission have previously concentrated on adiabatic approaches based on constrained static calculations ignoring dynamical excitations of the fissioning nucleus and the daughter products. Purpose: We explore the ability of dynamic mean-field methods to describe induced fission processes, using quadrupole boosts in the nuclide 240Pu as an example. Methods: Following upon the work presented in Goddard et al. [Phys. Rev. C 92, 054610 (2015)], 10.1103/PhysRevC.92.054610, quadrupole-constrained Hartree-Fock calculations are used to create a potential energy surface. An isomeric state and a state beyond the second barrier peak are excited by means of instantaneous as well as temporally extended gauge boosts with quadrupole shapes. The subsequent deexcitation is studied in a time-dependent Hartree-Fock simulation, with emphasis on fissioned final states. The corresponding fission fragment mass numbers are studied. Results: In general, the energy deposited by the quadrupole boost is quickly absorbed by the nucleus. In instantaneous boosts, this leads to fast shape rearrangements and violent dynamics that can ultimately lead to fission. This is a qualitatively different process than the deformation-induced fission. Boosts induced within a finite time window excite the system in a relatively gentler way and do induce fission but with a smaller energy deposition. Conclusions: The fission products obtained using boost-induced fission in time-dependent Hartree-Fock are more asymmetric than the fragments obtained in deformation-induced fission or the corresponding adiabatic approaches.
Boost-invariant Leptonic Observables and Reconstruction of Parent Particle Mass
Kawabata, Sayaka; Sumino, Yukinari; Yokoya, Hiroshi
2011-01-01
We propose a class of observables constructed from the lepton energy distribution, which are independent of the velocity of the parent particle if it is scalar or unpolarized. These observables may be used to measure properties of various particles in the LHC experiments. We demonstrate their usage in a determination of the Higgs boson mass.
Second order invariants and holography
Bonanno, Luca; Luongo, Orlando
2011-01-01
Motivated by recent works on the role of the Holographic principle in cosmology, we relate a class of second order Ricci invariants to the IR cutoff characterizing the holographic Dark Energy density. The choice of second order invariants provides an invariant way to account the problem of causality for the correct cosmological cutoff, since the presence of event horizons is not an \\emph{a priori} assumption. We find that these models work fairly well, by fitting the observational data, through a combined cosmological test with the use of SNeIa, BAO and CMB. This class of models is also able to overcome the fine-tuning and coincidence problems. Finally, to make a comparison with other recent models, we adopt the statistical tests AIC and BIC.
Invariant probabilities of transition functions
Zaharopol, Radu
2014-01-01
The structure of the set of all the invariant probabilities and the structure of various types of individual invariant probabilities of a transition function are two topics of significant interest in the theory of transition functions, and are studied in this book. The results obtained are useful in ergodic theory and the theory of dynamical systems, which, in turn, can be applied in various other areas (like number theory). They are illustrated using transition functions defined by flows, semiflows, and one-parameter convolution semigroups of probability measures. In this book, all results on transition probabilities that have been published by the author between 2004 and 2008 are extended to transition functions. The proofs of the results obtained are new. For transition functions that satisfy very general conditions the book describes an ergodic decomposition that provides relevant information on the structure of the corresponding set of invariant probabilities. Ergodic decomposition means a splitting of t...
Trace Invariance for Quaternion Matrices
Ralph John de la Cruz
2015-12-01
Full Text Available Let F be a f ield. It is a classical result in linear algebra that for each A, P ϵ Mn (F such that P is nonsingular, tr A = tr (PAP-1. We show in this paper that the preceding property does not hold true if F is the division ring of real quaternions. We show that the only quaternion matrices that have their trace invariant under unitary similarity are Hermitian matrices, and that the only matrices that have their trace invariant under similarity are real scalar matrices.
Instanton counting and Donaldson invariants
For a smooth projective toric surface we determine the Donaldson invariants and their wall-crossing in terms of the Nekrasov partition function. Using the solution of the Nekrasov conjecture and its refinement , we apply this result to give a generating function for the wall-crossing of Donaldson invariants of good walls of simply connected projective surfaces with b+ = 1 in terms of modular forms. This formula was proved earlier in more generally for simply connected 4-manifolds with b+ = 1, assuming the Kotschick- Morgan conjecture and it was also derived by physical arguments. (author)
Trace Invariance for Quaternion Matrices
Ralph John de la Cruz
2015-01-01
Let F be a f ield. It is a classical result in linear algebra that for each A, P ϵ Mn (F) such that P is nonsingular, tr A = tr (PAP-1). We show in this paper that the preceding property does not hold true if F is the division ring of real quaternions. We show that the only quaternion matrices that have their trace invariant under unitary similarity are Hermitian matrices, and that the only matrices that have their trace invariant under similarity are real scalar matrices.
Leptogenesis and a Jarlskog Invariant
Davidson, Sacha; Davidson, Sacha; Kitano, Ryuichiro
2004-01-01
The relation between low energy CP violating phases, and the CP asymmetry of leptogenesis, $\\epsilon$, is investigated. Although it is known that in general those are independent, there may be a relation when a model is specified. We construct a Jarlskog invariant which is proportional to $\\epsilon$ if the right-handed neutrino masses are hierarchical. Since the invariant can be expressed in terms of left-handed neutrino parameters--some measurable, and some not--it is useful in identifying the limits in which $\\epsilon$ is related to MNS phases.
Simple Algebras of Invariant Operators
Xiaorong Shen; J.D.H. Smith
2001-01-01
Comtrans algebras were introduced in as algebras with two trilinear operators, a commutator [x, y, z] and a translator , which satisfy certain identities. Previously known simple comtrans algebras arise from rectangular matrices, simple Lie algebras, spaces equipped with a bilinear form having trivial radical, spaces of hermitian operators over a field with a minimum polynomial x2+1. This paper is about generalizing the hermitian case to the so-called invariant case. The main result of this paper shows that the vector space of n-dimensional invariant operators furnishes some comtrans algebra structures, which are simple provided that certain Jordan and Lie algebras are simple.
Neuronal boost to evolutionary dynamics
de Vladar, Harold P.; Szathmáry, Eörs
2015-01-01
Standard evolutionary dynamics is limited by the constraints of the genetic system. A central message of evolutionary neurodynamics is that evolutionary dynamics in the brain can happen in a neuronal niche in real time, despite the fact that neurons do not reproduce. We show that Hebbian learning and structural synaptic plasticity broaden the capacity for informational replication and guided variability provided a neuronally plausible mechanism of replication is in place. The synergy between learning and selection is more efficient than the equivalent search by mutation selection. We also consider asymmetric landscapes and show that the learning weights become correlated with the fitness gradient. That is, the neuronal complexes learn the local properties of the fitness landscape, resulting in the generation of variability directed towards the direction of fitness increase, as if mutations in a genetic pool were drawn such that they would increase reproductive success. Evolution might thus be more efficient within evolved brains than among organisms out in the wild. PMID:26640653
Facilitated Asymmetric Exclusion
Gabel, Alan; Krapivsky, P. L.; Redner, S.
2010-01-01
We introduce a class of facilitated asymmetric exclusion processes in which particles are pushed by neighbors from behind. For the simplest version in which a particle can hop to its vacant right neighbor only if its left neighbor is occupied, we determine the steady state current and the distribution of cluster sizes on a ring. We show that an initial density downstep develops into a rarefaction wave that can have a jump discontinuity at the leading edge, while an upstep results in a shock w...
Morrison, James
1984-01-01
Asymmetric Synthesis, Volume 4: The Chiral Carbon Pool and Chiral Sulfur, Nitrogen, Phosphorus, and Silicon Centers describes the practical methods of obtaining chiral fragments. Divided into five chapters, this book specifically examines initial chiral transmission and extension. The opening chapter describes the so-called chiral carbon pool, the readily available chiral carbon fragments used as building blocks in synthesis. This chapter also provides a list of 375 chiral building blocks, along with their commercial sources, approximate prices, and methods of synthesis. Schemes involving
Speziale, Simone
2016-01-01
We study the SL(2,C) Clebsch-Gordan coefficients appearing in the lorentzian EPRL spin foam amplitudes for loop quantum gravity. We show how the amplitudes decompose into SU(2) nj-symbols at the vertices and integrals over boosts at the edges. The integrals define edge amplitudes that can be evaluated analytically using and adapting results in the literature, leading to a pure state sum model formulation. This procedure introduces virtual representations which, in a manner reminiscent to virtual momenta in Feynman amplitudes, are off-shell of the simplicity constraints present in the theory, but with the integrands that peak at the on-shell values. We point out some properties of the edge amplitudes which are helpful for numerical and analytical evaluations of spin foam amplitudes, and suggest among other things a simpler model useful for calculations of certain lowest order amplitudes. As an application, we estimate the large spin scaling behaviour of the simpler model, on a closed foam with all 4-valent edg...
Scale-invariant power spectra from a Weyl-invariant scalar-tensor theory
Myung, Yun Soo [Inje University, Institute of Basic Sciences and Department of Computer Simulation, Gimhae (Korea, Republic of); Park, Young-Jai [Sogang University, Department of Physics, Seoul (Korea, Republic of)
2016-02-15
We obtain scale-invariant scalar and tensor power spectra from a Weyl-invariant scalar-tensor theory in de Sitter spacetime. This implies that the Weyl invariance guarantees the implementation of the scale invariance of the power spectrum in de Sitter spacetime. We establish a deep connection between the Weyl invariance of the action and the scale invariance of the power spectrum in de Sitter spacetime. (orig.)
Donaldson invariants of symplectic manifolds
Sivek, Steven
2013-01-01
We prove that symplectic 4-manifolds with $b_1 = 0$ and $b^+ > 1$ have nonvanishing Donaldson invariants, and that the canonical class is always a basic class. We also characterize in many situations the basic classes of a Lefschetz fibration over the sphere which evaluate maximally on a generic fiber.
Identity from classical invariant theory
A simple derivation is given of a well-known relation involving the so-called Cayley Operator of classical invariant theory. The proof is induction-free and independent of Capelli's identity; it makes use only of a known-theorem in the theory of determinants and some elementary combinatorics
Supersymmetric gauge invariant interaction revisited
A supersymmetric Lagrangian invariant under local U(1) gauge transformations is written in terms of a non-chiral superfield which substitute the usual vector supermultiplet together with chiral and anti-chiral superfields. The Euler equations allow us to obtain the off-shell version of the usual Lagrangian for supersymmetric quantum-electrodynamics (SQED). (Author)
Geng, C. Q.; Geng, Lei
2005-01-01
We first briefly review tests on CPT invariance based on the consequences of the CPT theorem and then present some possible CPT tests due to exotic models in which some of the CPT conditions are lost, such as those without hermiticity.
Translation-invariant noncommutative renormalization
Tanasa, Adrian
2010-01-01
We review here the construction of a translation-invariant scalar model which was proved to be renormalizable on Moyal space. Some general considerations on non-local renormalizability are given. Finally, we present perspectives for generalizing these quantum field theoretical techniques to group field theory, a new setting for quantum gravity.
Lorentz invariance and gauge equivariance
Trying to place Lorentz and gauge transformations on the same foundation, it turns out that the first one generates invariance, the second one equivariance, at least for the abelian case. This similarity is not a hypothesis but is supported by and a consequence of the path integral formalism in quantum field theory.
Invariants in Supersymmetric Classical Mechanics
Alonso Izquierdo, Alberto; González León, Miguel Ángel; Mateos Guilarte, Juan
2000-01-01
[EN] The bosonic second invariant of SuperLiouville models in supersymmetric classical mechanics is described. [ES] El segundo campo cuántico de bosones invariante del modelo SuperLiouville es descrito en la mecanica clasica supersimétrica.
Invariant Classification of Gait Types
Fihl, Preben; Moeslund, Thomas B.
2008-01-01
This paper presents a method of classifying human gait in an invariant manner based on silhouette comparison. A database of artificially generated silhouettes is created representing the three main types of gait, i.e. walking, jogging, and running. Silhouettes generated from different camera angles...
A Many Particle Adiabatic Invariant
Hjorth, Poul G.
For a system of N charged particles moving in a homogeneous, sufficiently strong magnetic field, a many-particle adiabatic invariant constrains the collisional exchange of energy between the degrees of freedom perpendicular to and parallel to the magnetic field. A description of the phenomenon in...
Conjectured enumeration of Vassiliev invariants
Broadhurst, D J
1997-01-01
These conjectures are motivated by successful enumerations of irreducible Euler sums. Predictions for $\\beta_{15,10}$, $\\beta_{16,12}$ and $\\beta_{19,16}$ suggest that the action of sl and osp Lie algebras, on baguette diagrams with ladder insertions, fails to detect an invariant in each case.
Scale invariance and superfluid turbulence
Sen, Siddhartha, E-mail: siddhartha.sen@tcd.ie [CRANN, Trinity College Dublin, Dublin 2 (Ireland); R.K. Mission Vivekananda University, Belur 711 202, West Bengal (India); Ray, Koushik, E-mail: koushik@iacs.res.in [Department of Theoretical Physics, Indian Association for the Cultivation of Science, Calcutta 700 032 (India)
2013-11-11
We construct a Schroedinger field theory invariant under local spatial scaling. It is shown to provide an effective theory of superfluid turbulence by deriving, analytically, the observed Kolmogorov 5/3 law and to lead to a Biot–Savart interaction between the observed filament excitations of the system as well.
Pairing interaction and Galilei invariance
The relation between Galilei invariance and the energy weighted sum rule for a mass dipole operator is discussed using a monopole pairing interaction. It is found that the energy weighted sum rule for the mass dipole operator changes as much as 18% in medium and heavy nuclei. copyright 1997 The American Physical Society
Avoiding Anemia: Boost Your Red Blood Cells
... link, please review our exit disclaimer . Subscribe Avoiding Anemia Boost Your Red Blood Cells If you’re ... and sluggish, you might have a condition called anemia. Anemia is a common blood disorder that many ...
Anemia Boosts Stroke Death Risk, Study Finds
... page: https://medlineplus.gov/news/fullstory_160476.html Anemia Boosts Stroke Death Risk, Study Finds Blood condition ... 2016 (HealthDay News) -- Older stroke victims suffering from anemia -- a lack of red blood cells -- may have ...
On the generator of Lorentz boost
Wang Zhi-Yong; Xiong Cai-Dong
2006-01-01
Traditionally, the theory related to the spatial angular momentum has been studied completely, while the investigation in the generator of Lorentz boost is inadequate. This paper shows that the generator of Lorentz boost has a nontrivial physical significance: it endows a charged system with an electric moment, and has an important significance for the electrical manipulations of electron spin in spintronics. An alternative treatment and interpretation for the traditional Darwin term and spin-orbit coupling are given.
Internationalization of Boost Juice to Malaysia
Jane L. Menzies; Stuart C. Orr
2014-01-01
This case describes the process that the Australian juice retail chain, Boost Juice, has used to internationalize to Malaysia. The main objective of this case is to demonstrate good practice in regard to internationalization. The case provides the background of the juice bar industry in Malaysia and determines that it is an attractive market for new start-up juice bars. An analysis of Boost Juice's capability determined that the company utilized the skills of its staff, product innovations, b...
Asymmetric quantum cloning machines
A family of asymmetric cloning machines for quantum bits and N-dimensional quantum states is introduced. These machines produce two approximate copies of a single quantum state that emerge from two distinct channels. In particular, an asymmetric Pauli cloning machine is defined that makes two imperfect copies of a quantum bit, while the overall input-to-output operation for each copy is a Pauli channel. A no-cloning inequality is derived, characterizing the impossibility of copying imposed by quantum mechanics. If p and p' are the probabilities of the depolarizing channels associated with the two outputs, the domain in (√p,√p')-space located inside a particular ellipse representing close-to-perfect cloning is forbidden. This ellipse tends to a circle when copying an N-dimensional state with N→∞, which has a simple semi-classical interpretation. The symmetric Pauli cloning machines are then used to provide an upper bound on the quantum capacity of the Pauli channel of probabilities px, py and pz. The capacity is proven to be vanishing if (√px, √py, √pz) lies outside an ellipsoid whose pole coincides with the depolarizing channel that underlies the universal cloning machine. Finally, the tradeoff between the quality of the two copies is shown to result from a complementarity akin to Heisenberg uncertainty principle. (author)
Reuveni, Shlomi; Eliazar, Iddo; Yechiali, Uri
2011-10-01
We introduce and explore the asymmetric inclusion process (ASIP), an exactly solvable bosonic counterpart of the fermionic asymmetric exclusion process (ASEP). In both processes, random events cause particles to propagate unidirectionally along a one-dimensional lattice of n sites. In the ASEP, particles are subject to exclusion interactions, whereas in the ASIP, particles are subject to inclusion interactions that coalesce them into inseparable clusters. We study the dynamics of the ASIP, derive evolution equations for the mean and probability generating function (PGF) of the sites’ occupancy vector, obtain explicit results for the above mean at steady state, and describe an iterative scheme for the computation of the PGF at steady state. We further obtain explicit results for the load distribution in steady state, with the load being the total number of particles present in all lattice sites. Finally, we address the problem of load optimization, and solve it under various criteria. The ASIP model establishes bridges between statistical physics and queueing theory as it represents a tandem array of queueing systems with (unlimited) batch service, and a tandem array of growth-collapse processes.
Asymmetric Dark Matter Models and the LHC Diphoton Excess
Frandsen, Mads T
2016-01-01
The existence of dark matter (DM) and the origin of the baryon asymmetry are persistent indications that the SM is incomplete. More recently, the ATLAS and CMS experiments have observed an excess of diphoton events with invariant mass of about 750 GeV. One interpretation of this excess is decays of a new spin-0 particle with a sizable diphoton partial width, e.g. induced by new heavy weakly charged particles. These are also key ingredients in models cogenerating asymmetric DM and baryons via sphaleron interactions and an initial particle asymmetry. We explore what consequences the new scalar may have for models of asymmetric DM that attempt to account for the similarity of the dark and visible matter abundances.
Larkoski, Andrew
2015-04-01
Jets are collimated streams of high-energy particles ubiquitous at any particle collider experiment and serve as proxy for the production of elementary particles at short distances. As the Large Hadron Collider at CERN continues to extend its reach to ever higher energies and luminosities, an increasingly important aspect of any particle physics analysis is the study and identification of jets, electroweak bosons, and top quarks with large Lorentz boosts. In addition to providing a unique insight into potential new physics at the tera-electron volt energy scale, high energy jets are a sensitive probe of emergent phenomena within the Standard Model of particle physics and can teach us an enormous amount about quantum chromodynamics itself. Jet physics is also invaluable for lower-level experimental issues including triggering and background reduction. It is especially important for the removal of pile-up, which is radiation produced by secondary proton collisions that contaminates every hard proton collision event in the ATLAS and CMS experiments at the Large Hadron Collider. In this talk, I will review the myriad ways that jets and jet physics are being exploited at the Large Hadron Collider. This will include a historical discussion of jet algorithms and the requirements that these algorithms must satisfy to be well-defined theoretical objects. I will review how jets are used in searches for new physics and ways in which the substructure of jets is being utilized for discriminating backgrounds from both Standard Model and potential new physics signals. Finally, I will discuss how jets are broadening our knowledge of quantum chromodynamics and how particular measurements performed on jets manifest the universal dynamics of weakly-coupled conformal field theories.
Philippine campaign boosts child immunizations.
Manuel-santana, R
1993-03-01
In 1989, USAID awarded the Philippines a 5-year, US $50 million Child Survival Program targeting improvement in immunization coverage of children, prenatal care coverage for pregnant women, and contraceptive prevalence. Upon successful completion of performance benchmarks at the end of each year, USAID released monies to fund child survival activities for the following year. This program accomplished a major program goal, which was decentralization of health planning. The Philippine Department of Health soon incorporated provincial health planning. The Philippine Department of Health soon incorporated provincial health planning in its determination of allocation of resources. Social marketing activities contributed greatly to success in achieving the goal of boosting the immunization coverage rate for the 6 antigens listed under the Expanded Program for Immunization (51%-85% of infants, 1986-1991). In fact, rural health officers in Tarlac Province in Central Luzon went from household to household to talk to mothers about the benefits of immunizing a 1-year-old child, thereby contributing greatly to their achieving a 95% full immunization coverage rate by December 1991. Social marketing techniques included modern marketing strategies and multimedia channels. They first proved successful in metro Manila which, at the beginning of the campaign, had the lowest immunization rate of all 14 regions. Every Wednesday was designated immunization day and was when rural health centers vaccinated the children. Social marketing also successfully publicized oral rehydration therapy (ORT), breast feeding, and tuberculosis control. Another contributing factor to program success in child survival activities was private sector involvement. For example, the Philippine Pediatric Society helped to promote ORT as the preferred treatment for acute diarrhea. Further, the commercial sector distributed packets of oral rehydration salts and even advertised its own ORT product. At the end of 2
Gauge-invariant cosmological density perturbations
Gauge-invariant formulation of cosmological density perturbation theory is reviewed with special emphasis on its geometrical aspects. Then the gauge-invariant measure of the magnitude of a given perturbation is presented. (author)
Alternative Asymmetric Stochastic Volatility Models
M. Asai (Manabu); M.J. McAleer (Michael)
2010-01-01
textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is
Baryogenesis in a CP invariant theory
Hook, Anson
2015-01-01
We consider baryogenesis in a model which has a CP invariant Lagrangian, CP invariant initial conditions and does not spontaneously break CP at any of the minima. We utilize the fact that tunneling processes between CP invariant minima can break CP to implement baryogenesis. CP invariance requires the presence of two tunneling processes with opposite CP breaking phases and equal probability of occurring. In order for the entire visible universe to see the same CP violating phase, we consider ...
Energy balance invariance for interacting particle systems
Yavari, Arash; Marsden, Jerrold E.
2009-01-01
This paper studies the principle of invariance of balance of energy and its consequences for a system of interacting particles under groups of transformations. Balance of energy and its invariance is first examined in Euclidean space. Unlike the case of continuous media, it is shown that conservation and balance laws do not follow from the assumption of invariance of balance of energy under time-dependent isometries of the ambient space. However, the postulate of invariance of balance of ener...
Boosted searches for new physics at the LHC
Schlaffer, Matthias J.
2015-09-15
During the first run of the LHC, no apparent signs of new physics beyond the Standard Model were discovered, but rather the Standard Model-like properties of the Higgs particle confirmed. Therefore, new and powerful methods are needed to disclose the traces of new physics, which is expected to be at the TeV scale in order to solve the hierarchy problem. In this thesis, we propose two complementary strategies for the quest for new physics at the LHC. First, we show how a very boosted Higgs in association with a hard jet can be used to determine the important top Yukawa coupling in gluon fusion. In the inclusive gluon fusion process this is not feasible since possible deviations from its Standard Model value are combined and can even cancel with the effective Higgs-gluon interaction mediated by new top partners. This cancellation is motivated within minimal composite Higgs models but also in certain regions of the MSSM parameter space and can lead to a Standard Model-like inclusive cross section that allows no conclusions on the mass spectrum of the new physics. We work out in detail how this degeneracy can be broken in the boosted Higgs channel and find that even in the worst case scenario with a Standard Model-like inclusive cross section, the top Yukawa coupling can be constrained to 0.8-1.3 times its Standard Model value at 95% CL with an integrated luminosity of 3 000 fb{sup -1}. The second strategy is targeted at direct stop and sbottom searches in the fully hadronic top decay channel. Since the stop, sbottom and neutralino masses are unknown, very different event shapes are imaginable, ranging from unboosted top quarks and low missing energy to highly boosted top quarks and large missing energy in the final state. In order to cover a wide range of possible event shapes and consequently stop, sbottom, and neutralino masses, we combine several top taggers based on jet substructure techniques to obtain a scale invariant search strategy. The performance of this
Boosted searches for new physics at the LHC
During the first run of the LHC, no apparent signs of new physics beyond the Standard Model were discovered, but rather the Standard Model-like properties of the Higgs particle confirmed. Therefore, new and powerful methods are needed to disclose the traces of new physics, which is expected to be at the TeV scale in order to solve the hierarchy problem. In this thesis, we propose two complementary strategies for the quest for new physics at the LHC. First, we show how a very boosted Higgs in association with a hard jet can be used to determine the important top Yukawa coupling in gluon fusion. In the inclusive gluon fusion process this is not feasible since possible deviations from its Standard Model value are combined and can even cancel with the effective Higgs-gluon interaction mediated by new top partners. This cancellation is motivated within minimal composite Higgs models but also in certain regions of the MSSM parameter space and can lead to a Standard Model-like inclusive cross section that allows no conclusions on the mass spectrum of the new physics. We work out in detail how this degeneracy can be broken in the boosted Higgs channel and find that even in the worst case scenario with a Standard Model-like inclusive cross section, the top Yukawa coupling can be constrained to 0.8-1.3 times its Standard Model value at 95% CL with an integrated luminosity of 3 000 fb-1. The second strategy is targeted at direct stop and sbottom searches in the fully hadronic top decay channel. Since the stop, sbottom and neutralino masses are unknown, very different event shapes are imaginable, ranging from unboosted top quarks and low missing energy to highly boosted top quarks and large missing energy in the final state. In order to cover a wide range of possible event shapes and consequently stop, sbottom, and neutralino masses, we combine several top taggers based on jet substructure techniques to obtain a scale invariant search strategy. The performance of this approach
Engineered Asymmetric Synthetic Vesicles
Lu, Li; Chiarot, Paul
2013-11-01
Synthetic vesicles are small, fluid-filled spheres that are enclosed by a bilayer of lipid molecules. They can be used as models for investigating membrane biology and as delivery vehicles for pharmaceuticals. In practice, it is difficult to simultaneously control membrane asymmetry, unilamellarity, vesicle size, vesicle-to-vesicle uniformity, and luminal content. Membrane asymmetry, where each leaflet of the bilayer is composed of different lipids, is of particular importance as it is a feature of most natural membranes. In this study, we leverage microfluidic technology to build asymmetric vesicles at high-throughput. We use the precise flow control offered by microfluidic devices to make highly uniform emulsions, with controlled internal content, that serve as templates to build the synthetic vesicles. Flow focusing, dielectrophoretic steering, and interfacial lipid self-assembly are critical procedures performed on-chip to produce the vesicles. Fluorescent and confocal microscopy are used to evaluate the vesicle characteristics.
I. Cabrera-Munguia
2015-04-01
Full Text Available A 6-parametric asymptotically flat exact solution, describing a two-body system of asymmetric black dyons, is studied. The system consists of two unequal counterrotating Kerr–Newman black holes, endowed with electric and magnetic charges which are equal but opposite in sign, separated by a massless strut. The Smarr formula is generalized in order to take into account their contribution to the mass. The expressions for the horizon half-length parameters σ1 and σ2, as functions of the Komar parameters and of the coordinate distance, are displayed, and the thermodynamic properties of the two-body system are studied. Furthermore, the seven physical parameters satisfy a simple algebraic relation which can be understood as a dynamical scenario, in which the physical properties of one body are affected by the ones of the other body.
We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC
Organizing for Asymmetric Collaboration
Nielsen, Jørn Flohr; Sørensen, Henrik B.
meet each other. On the contrary, we assume that asymmetry is both important and normal; moreover, asymmetry should be considered to be more complex than economists indicate with their concept of asymmetric information. Thus, the aim of the paper is to explore how asymmetries related to partners...... The vision of new organizational forms consists of less-organized networks and alliances between organizations, in which collaborative capabilities are assumed to be crucial (Miles et al., 2005). The path to such new forms may go through fragile cooperative efforts. Despite the good will of many......' different motives and different situational factors appear in an interorganizational setting. We classify interfaces according to the symmetry/asymmetry in the respective parent organizations' resources, commitment, and control of representatives and indicate how classification schemes can be used to...
Annihilating Asymmetric Dark Matter
Bell, Nicole F; Shoemaker, Ian M
2014-01-01
The relic abundance of particle and antiparticle dark matter (DM) need not be vastly different in thermal asymmetric dark matter (ADM) models. By considering the effect of a primordial asymmetry on the thermal Boltzmann evolution of coupled DM and anti-DM, we derive the requisite annihilation cross section. This is used in conjunction with CMB and Fermi-LAT gamma-ray data to impose a limit on the number density of anti-DM particles surviving thermal freeze-out. When the extended gamma-ray emission from the Galactic Center is reanalyzed in a thermal ADM framework, we find that annihilation into $\\tau$ leptons prefer anti-DM number densities 1-4$\\%$ that of DM while the $b$-quark channel prefers 50-100$\\%$.
Dadhichi, Lokrshi Prawar; Maitra, Ananyo; Ramaswamy, Sriram
2016-01-01
As the constituents of a flock are polar, one expects a fore-aft asymmetry in their interactions. We show here that the resulting antisymmetric part of the "exchange coupling" between a bird and its neighbours, if large enough, destabilizes the flock through spontaneous turning of the birds. The same asymmetry also yields a natural mechanism for a difference between the speed of advection of information along the flock and the speed of the flock itself. We show that the absence of detailed balance, and not merely the breaking of Galilean invariance, is responsible for this difference. We delineate the conditions on parameters and wavenumber for the existence of the turning instability. Lastly we present an alternative perspective based on flow-alignment effects in an active liquid crystal with turning inertia in contact with a momentum sink.
A functional LMO invariant for Lagrangian cobordisms
Cheptea, Dorin; Habiro, Kazuo; Massuyeau, Gwénaël
2008-01-01
Jacobi diagrams. We prove some properties of this functorial LMO invariant, including its universality among rational finite-type invariants of Lagrangian cobordisms. Finally, we apply the LMO functor to the study of homology cylinders from the point of view of their finite-type invariants....
On Link Invariants and Topological String Amplitudes
Ramadevi, P; Sarkar, Tapobrata
2001-01-01
We explicitly show that the new polynomial invariants for knots, upto nine crossings, agree with the Ooguri-Vafa conjecture relating Chern-Simons gauge theory to topological string theory on the resolution of the conifold. From the multi-component link invariants in SU(N) Chern-Simons theory, we suggest a form for the new polynomial invariants.
Invariance for Single Curved Manifold
Castro, Pedro Machado Manhaes de
2012-08-01
Recently, it has been shown that, for Lambert illumination model, solely scenes composed by developable objects with a very particular albedo distribution produce an (2D) image with isolines that are (almost) invariant to light direction change. In this work, we provide and investigate a more general framework, and we show that, in general, the requirement for such in variances is quite strong, and is related to the differential geometry of the objects. More precisely, it is proved that single curved manifolds, i.e., manifolds such that at each point there is at most one principal curvature direction, produce invariant is surfaces for a certain relevant family of energy functions. In the three-dimensional case, the associated energy function corresponds to the classical Lambert illumination model with albedo. This result is also extended for finite-dimensional scenes composed by single curved objects. © 2012 IEEE.
Geometry-Invariant Resonant Cavities
Liberal, Iñigo; Engheta, Nader
2015-01-01
Resonant cavities are one of the basic building blocks in various disciplines of science and technology, with numerous applications ranging from abstract theoretical modeling to everyday life devices. The eigenfrequencies of conventional cavities are a function of its geometry, and, thus, the size and shape of a resonant cavity is selected in order to operate at a specific frequency. Here, we demonstrate theoretically the existence of geometry-invariant resonant cavities, i.e., resonators whose eigenfrequency is invariant with respect to geometrical deformations. This effect is obtained by exploiting the unusual properties of zero-index metamaterials, which enable decoupling of the time and spatial field variations. This new class of resonators may inspire alternative design concepts, and it might lead to the first generation of deformable resonant devices.
Gauge invariance and holographic renormalization
Keun-Young Kim
2015-10-01
Full Text Available We study the gauge invariance of physical observables in holographic theories under the local diffeomorphism. We find that gauge invariance is intimately related to the holographic renormalization: the local counter terms defined in the boundary cancel most of gauge dependences of the on-shell action as well as the divergences. There is a mismatch in the degrees of freedom between the bulk theory and the boundary one. We resolve this problem by noticing that there is a residual gauge symmetry (RGS. By extending the RGS such that it satisfies infalling boundary condition at the horizon, we can understand the problem in the context of general holographic embedding of a global symmetry at the boundary into the local gauge symmetry in the bulk.
Relativistically invariant photonic wave packets
Bradler, Kamil
2009-01-01
We present a photonic wave packet construction which is immune against the decoherence effects induced by the action of the Lorentz group. The amplitudes of a pure quantum state representing the wave packet remain invariant irrespective of the reference frame into which the wave packet has been transformed. Transmitted information is encoded in the helicity degrees of freedom of two correlated momentum modes. The helicity encoding is considered to be particularly suitable for free-space communication. The integral part of the story is information retrieval on the receiver's side. We employed probably the simplest possible helicity (polarization) projection measurement originally studied by Peres and Terno. Remarkably, the same conditions ensuring the invariance of the wave packet also guarantee perfect distinguishability in the process of measuring the helicity.
Anisotropic invariance in minisuperspace models
Chagoya, Javier; Sabido, Miguel
2016-06-01
In this paper we introduce invariance under anisotropic transformations to cosmology. This invariance is one of the key ingredients of the theory of quantum gravity at a Lifshitz point put forward by Hořava. We find that this new symmetry in the minisuperspace introduces characteristics to the model that can be relevant in the ultraviolet regime. For example, by canonical quantization we find a Schrödinger-type equation which avoids the problem of frozen time in quantum cosmology. For simple cases we obtain solutions to this quantum equation in a Kantowski–Sachs (KS) minisuperspace. At the classical level, we study KS and Friedmann–Robertson–Walker cosmologies, obtaining modifications to the solutions of general relativity that can be relevant in the early Universe.
Blur Invariants and Projection Operators
Flusser, Jan; Suk, Tomáš; Boldyš, Jiří; Zitová, Barbara
Indbruck: ACTA Press, 2013 - (Linsen, L.; Kampel, M.), s. 305-312. (Computer Graphics and Imaging. 798). ISBN 978-0-88986-944-8. [Signal Processing , Pattern Recognition and Applications (SPPRA 2013). Insbruck (AT), 12.02.2013-14.02.2013] R&D Projects: GA ČR GAP103/11/1552 Keywords : image recognition * Fourier transform * projection operators * invariants Subject RIV: JD - Computer Applications, Robotics
A reparametrization invariant surface ordering
Gustavsson, Andreas
2005-01-01
We introduce a notion of a non-Abelian loop gauge field defined on points in loop space. For this purpose we first find an infinite-dimensional tensor product representation of the Lie algebra which is particularly suited for fields on loop space. We define the non-Abelian Wilson surface as a `time' ordered exponential in terms of this loop gauge field and show that it is reparametrization invariant.
Molecular invariants: atomic group valence
Molecular invariants may be deduced in a very compact way through Grassman algebra. In this work, a generalized valence is defined for an atomic group; it reduces to the Known expressions for the case of an atom in a molecule. It is the same of the correlations between the fluctions of the atomic charges qc and qd (C belongs to the group and D does not) around their average values. Numerical results agree with chemical expectation. (author)
Gauge Invariance in Classical Electrodynamics
Engelhardt, W
2005-01-01
The concept of gauge invariance in classical electrodynamics assumes tacitly that Maxwell's equations have unique solutions. By calculating the electromagnetic field of a moving particle both in Lorenz and in Coulomb gauge and directly from the field equations we obtain, however, contradicting solutions. We conclude that the tacit assumption of uniqueness is not justified. The reason for this failure is traced back to the inhomogeneous wave equations which connect the propagating fields and their sources at the same time.
Learning Local Invariant Mahalanobis Distances
Fetaya, Ethan; Ullman, Shimon
2015-01-01
For many tasks and data types, there are natural transformations to which the data should be invariant or insensitive. For instance, in visual recognition, natural images should be insensitive to rotation and translation. This requirement and its implications have been important in many machine learning applications, and tolerance for image transformations was primarily achieved by using robust feature vectors. In this paper we propose a novel and computationally efficient way to learn a loca...
SCALe-invariant Integral Surfaces
Zanni, C.; A. Bernhardt; Quiblier, M.; Cani, M.-P.
2013-01-01
Extraction of skeletons from solid shapes has attracted quite a lot of attention, but less attention was paid so far to the reverse operation: generating smooth surfaces from skeletons and local radius information. Convolution surfaces, i.e. implicit surfaces generated by integrating a smoothing kernel along a skeleton, were developed to do so. However, they failed to reconstruct prescribed radii and were unable to model large shapes with fine details. This work introduces SCALe-invariant Int...
Conformal Invariance of Graphene Sheets
Giordanelli, I.; Posé, N.; Mendoza, M.; Herrmann, H. J.
2016-01-01
Suspended graphene sheets exhibit correlated random deformations that can be studied under the framework of rough surfaces with a Hurst (roughness) exponent 0.72 ± 0.01. Here, we show that, independent of the temperature, the iso-height lines at the percolation threshold have a well-defined fractal dimension and are conformally invariant, sharing the same statistical properties as Schramm-Loewner evolution (SLEκ) curves with κ = 2.24 ± 0.07. Interestingly, iso-height lines of other rough surfaces are not necessarily conformally invariant even if they have the same Hurst exponent, e.g. random Gaussian surfaces. We have found that the distribution of the modulus of the Fourier coefficients plays an important role on this property. Our results not only introduce a new universality class and place the study of suspended graphene membranes within the theory of critical phenomena, but also provide hints on the long-standing question about the origin of conformal invariance in iso-height lines of rough surfaces. PMID:26961723
Finite type invariants and fatgraphs
Andersen, Jørgen Ellegaard; Bene, Alex; Meilhan, Jean-Baptiste Odet Thierry;
2010-01-01
the link invariant of Andersen–Mattes–Reshetikhin computed relative to choices determined by the fatgraph G; this provides a basic connection between 2d geometry and 3d quantum topology. For each fixed G, this invariant is shown to be universal for homology cylinders, i.e., G establishes an......We define an invariant G(M) of pairs M,G , where M is a 3-manifold obtained by surgery on some framed link in the cylinder Σ×I , Σ is a connected surface with at least one boundary component, and G is a fatgraph spine of Σ. In effect, G is the composition with the ιn maps of Le–Murakami–Ohtsuki of...... isomorphism from an appropriate vector space of homology cylinders to a certain algebra of Jacobi diagrams. Via composition for any pair of fatgraph spines G,G′ of Σ, we derive a representation of the Ptolemy groupoid, i.e., the combinatorial model for the fundamental path groupoid of Teichmüller space, as a...
HUANG Bo-Wen; GU Zhi-Yu; QIAN Shang-Wu
2005-01-01
This article puts forward a general shape invariant potential, which includes the translational shape invariant potential and scaling shape invariant potential as two particular cases, and derives the set of linear differential equations for obtaining general solutions of the generalized shape invariance condition.
Comparative Study of 4-Switch Buck-Boost Controller and Regular Buck-Boost
Taufik Taufik
2011-01-01
Full Text Available A very important characteristic that dc-dc converters require is the ability to efficiently regulate an output voltage with a wide ranging value of input voltages. A recently developed solution to this requirement is a synchronous 4-Switch Buck-Boost controller developed by Linear Technology. The Linear Technology’s LTC3780 controller chip enables the adoption of a 4-Switch switching topology as opposed to the traditional single-switch Buck-Boost topology. In this paper, the LTC3780’s 4-Switch BuckBoost topology is analyzed and its performance is compared against those of the regular single-switch Buck-Boost topology. Results from computer simulations demonstrate the benefits of using the 4-switch approach than the conventional buck-boost method.
Nanosheet-enhanced asymmetric induction of chiral α-amino acids in catalytic aldol reaction.
Zhao, Li-Wei; Shi, Hui-Min; Wang, Jiu-Zhao; He, Jing
2012-11-26
An efficient ligand design strategy towards boosting asymmetric induction was proposed, which simply employed inorganic nanosheets to modify α-amino acids and has been demonstrated to be effective in vanadium-catalyzed epoxidation of allylic alcohols. Here, the strategy was first extended to zinc-catalyzed asymmetric aldol reaction, a versatile bottom-up route to make complex functional compounds. Zinc, the second-most abundant transition metal in humans, is an environment-friendly catalytic center. The strategy was then further proved valid for organocatalyzed metal-free asymmetric catalysis, that is, α-amino acid catalyzed asymmetric aldol reaction. Visible improvement of enantioselectivity was experimentally achieved irrespective of whether the nanosheet-attached α-amino acids were applied as chiral ligands together with catalytic Zn(II) centers or as chiral catalysts alone. The layered double hydroxide nanosheet was clearly found by theoretical calculations to boost ee through both steric and H-bonding effects; this resembles the role of a huge and rigid substituent. PMID:23074138
Quantum moment maps and invariants for G-invariant star products
Hamachi, Kentaro
2002-01-01
We study a quantum moment map and propose an invariant for $G$-invariant star products on a $G$-transitive symplectic manifold. We start by describing a new method to construct a quantum moment map for $G$-invariant star products of Fedosov type. We use it to obtain an invariant that is invariant under $G$-equivalence. In the last section we give two simple examples of such invariants, which involve non-classical terms and provide new insights into the classification of $G$-invariant star pro...
Concomitant boost radiotherapy in oropharynx carcinomas
Fifty-five patients with resectable and unresectable oropharynx carcinomas were treated with concomitant boost radiotherapy. Forty-two of the patients (76%) had stages III-IV disease. Although none of the patients had undergone major surgery to the primary tumor, 11 had neck dissections prior to radiotherapy, and 19 (35%) received chemotherapy. The planned total tumor dose was 69.9 Gy, delivered over 5.5 weeks. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 13 fractions of 1.5 Gy each, as a second daily fraction in a progressively accelerated schedule; the prescribed dose outside the boost volume thus was 50.4 Gy. Median follow-up for surviving patients was 31.5 months (range: 16-65 months). All patients but one completed the planned radiotherapy schedule. According to the RTOG scoring system, 48 patients (88%) presented with grades 3-4 acute toxicity. The rate of grades 3-4 late complications was 12%. At three years the actuarial locoregional control rate was 69.5% and overall survival was 60%. We conclude that this concomitant boost schedule is feasible and does not seem to be associated with an excess risk of late complications. Acute toxicity was higher in association with chemotherapy, but remained manageable. Although the oncological results appear encouraging, evaluation of the efficacy of concomitant boost schedules compared with conventionally fractionated irradiation with or without concomitant chemotherapy requires prospective randomized trials. (orig.)
Concomitant boost radiotherapy in oropharynx carcinomas
Bieri, S.; Allal, A.S.; Kurtz, J.M. [Ospedale San Giovanni, Bellinzona (Switzerland). Dept. of Radiation Oncology; Dulguerov, P.; Lehmann, W. [Geneva Univ. Hospital (Switzerland). Div. of Head and Neck Surgery
1998-12-31
Fifty-five patients with resectable and unresectable oropharynx carcinomas were treated with concomitant boost radiotherapy. Forty-two of the patients (76%) had stages III-IV disease. Although none of the patients had undergone major surgery to the primary tumor, 11 had neck dissections prior to radiotherapy, and 19 (35%) received chemotherapy. The planned total tumor dose was 69.9 Gy, delivered over 5.5 weeks. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 13 fractions of 1.5 Gy each, as a second daily fraction in a progressively accelerated schedule; the prescribed dose outside the boost volume thus was 50.4 Gy. Median follow-up for surviving patients was 31.5 months (range: 16-65 months). All patients but one completed the planned radiotherapy schedule. According to the RTOG scoring system, 48 patients (88%) presented with grades 3-4 acute toxicity. The rate of grades 3-4 late complications was 12%. At three years the actuarial locoregional control rate was 69.5% and overall survival was 60%. We conclude that this concomitant boost schedule is feasible and does not seem to be associated with an excess risk of late complications. Acute toxicity was higher in association with chemotherapy, but remained manageable. Although the oncological results appear encouraging, evaluation of the efficacy of concomitant boost schedules compared with conventionally fractionated irradiation with or without concomitant chemotherapy requires prospective randomized trials. (orig.)
Positive Semidefinite Metric Learning with Boosting
Shen, Chunhua; Wang, Lei; Hengel, Anton van den
2009-01-01
The learning of appropriate distance metrics is a critical problem in image classification and retrieval. In this work, we propose a boosting-based technique, termed \\BoostMetric, for learning a Mahalanobis distance metric. One of the primary difficulties in learning such a metric is to ensure that the Mahalanobis matrix remains positive semidefinite. Semidefinite programming is sometimes used to enforce this constraint, but does not scale well. \\BoostMetric is instead based on a key observation that any positive semidefinite matrix can be decomposed into a linear positive combination of trace-one rank-one matrices. \\BoostMetric thus uses rank-one positive semidefinite matrices as weak learners within an efficient and scalable boosting-based learning process. The resulting method is easy to implement, does not require tuning, and can accommodate various types of constraints. Experiments on various datasets show that the proposed algorithm compares favorably to those state-of-the-art methods in terms of classi...
Effect of current electrode positions and of Gaussian noise on tensorial invariants
Complete text of publication follows. On basis of magnetotelluric invariant studies, from an old (the so-called 'potential gradient mapping') method (described in details by Varga et al., 2008) we developed a tensorial DC electrical resistivity mapping technique. The well known tensorial form of the differential Ohm's law provides a 2x2 resistivity tensor, which relates the horizontal current density vector and the corresponding electric field vector. In the DC apparent resistivity tensor there are three independent rotational invariants, so an arbitrary 1D, an arbitrary 2D and an arbitrary 3D indicator (plus the measuring direction) completely determine the resistivity tensor. Over a 3D numerical model, any 1D invariant-indicator (det, ssq, trace, WAL I1) proved to be equally useful, but the multidimensional (2D: WAL-I2 and 3D: WAL-I3) invariants were informative only in case of very significant subsurface inhomogeneities. Moreover, the multidimensional indicators were very much influenced by the Gaussian noise. (We added a 3 % noise to the model response.) In a field study, carried out in an archaeological site over a buried wall remnant, we investigated the effect of various current electrode positions to all these invariant parameters. Ten different electrode position systems (asymmetric, diagonal, offset, rotated, elongated, shortened, etc.) were realized. Each 1D invariant provided good image about the subsurface structure; the 2D invariant proved to be partly useful, while the 3D invariant was completely useless. These results might be instructive, even somewhat warning for magnetotellurics. Acknowledgement: Hungarian Scientific Research Fund, NI 61013.
Volume conjecture for $SU(n)$-invariants
Chen, Qingtao; Zhu, Shengmao
2015-01-01
This paper discuss an intrinsic relation among congruent relations \\cite{CLPZ}, cyclotomic expansion and Volume Conjecture for $SU(n)$ invariants. Motivated by the congruent relations for $SU(n)$ invariants obtained in our previous work \\cite{CLPZ}, we study certain limits of the $SU(n)$ invariants at various roots of unit. First, we prove a new symmetry property for the $SU(n)$ invariants by using a symmetry of colored HOMFLYPT invariants. Then we propose some conjectural formulas including the cyclotomic expansion conjecture and volume conjecture for $SU(n)$ invariants (specialization of colored HOMFLYPT invariants). We also give the proofs of these conjectural formulas for the case of figure-eight knot.
Centrifugal compressor design for electrically assisted boost
Y Yang, M.; Martinez-Botas, R. F.; Zhuge, W. L.; Qureshi, U.; Richards, B.
2013-12-01
Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically.
Improved Stereo Matching With Boosting Method
Shiny B
2015-06-01
Full Text Available Abstract This paper presents an approach based on classification for improving the accuracy of stereo matching methods. We propose this method for occlusion handling. This work employs classification of pixels for finding the erroneous disparity values. Due to the wide applications of disparity map in 3D television medical imaging etc the accuracy of disparity map has high significance. An initial disparity map is obtained using local or global stereo matching methods from the input stereo image pair. The various features for classification are computed from the input stereo image pair and the obtained disparity map. Then the computed feature vector is used for classification of pixels by using GentleBoost as the classification method. The erroneous disparity values in the disparity map found by classification are corrected through a completion stage or filling stage. A performance evaluation of stereo matching using AdaBoostM1 RUSBoost Neural networks and GentleBoost is performed.
Boost Breaking in the EFT of Inflation
Delacretaz, Luca V; Senatore, Leonardo
2015-01-01
If time-translations are spontaneously broken, so are boosts. This symmetry breaking pattern can be non-linearly realized by either just the Goldstone boson of time translations, or by four Goldstone bosons associated with time translations and boosts. In this paper we extend the Effective Field Theory of Multifield Inflation to consider the case in which the additional Goldstone bosons associated with boosts are light and coupled to the Goldstone boson of time translations. The symmetry breaking pattern forces a coupling to curvature so that the mass of the additional Goldstone bosons is predicted to be equal to $\\sqrt{2}H$ in the vast majority of the parameter space where they are light. This pattern therefore offers a natural way of generating self-interacting particles with Hubble mass during inflation. After constructing the general effective Lagrangian, we study how these particles mix and interact with the curvature fluctuations, generating potentially detectable non-Gaussian signals.
Centrifugal compressor design for electrically assisted boost
Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically
Metal rolling - Asymmetrical rolling process
Alexa, V.; Raţiu, S.; Kiss, I.
2016-02-01
The development of theory and practice related to the asymmetric longitudinal rolling process is based on the general theory of metalworking by pressure and symmetric rolling theory, to which a large number of scientists brought their contribution. The rolling of metal materials was a serious problem throughout history, either economically or technically, because the plating technologies enabled the consumption of raw materials (scarce and expensive) to be reduced, while improving the mechanical properties. Knowing the force parameters related to asymmetric rolling leads to the optimization of energy and raw material consumption. This paper presents data on symmetric rolling process, in order to comparatively highlight the particularities of the asymmetric process.
Concomitant boost radiotherapy in oropharynx carcinomas
Bieri, Sabine; Allal, Abdelkarim Said; Dulguerov, Pavel; Lehmann, Willy; Kurtz, John
1998-01-01
Fifty-five patients with resectable and unresectable oropharynx carcinomas were treated with concomitant boost radiotherapy. Forty-two of the patients (76%) had stages III-IV disease. Although none of the patients had undergone major surgery to the primary tumor, 11 had neck dissections prior to radiotherapy, and 19 (35%) received chemotherapy. The planned total tumor dose was 69.9 Gy, delivered over 5.5 weeks. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 1...
Entanglement asymmetry for boosted black branes
Mishra, Rohit
2016-01-01
We study the effects of asymmetry in entanglement thermodynamics of the CFT subsystems. It is found that `boosted' $p$-branes backgrounds give rise to the first law of the entanglement thermodynamics where the CFT pressure plays decisive role in the entanglement. Two different strip like subsystems, one parallel to the boost and the other perpendicular, are studied in the perturbative regime, where $T_{thermal}\\ll T_E$. We also discuss the AdS-wave backgrounds where some universal bounds can be obtained.
Three papers on boosting: an introduction
Koltchinskii, Vladimir; Yu, Bin
2004-01-01
The notion of boosting originated in the Machine Learning literature in the 1980's [VALIANT, L.G. (1984). A theory of the learnable. In Proc. 16th Annual ACM Symposium on Theory of Computing 436-445. ACM Press, New York]. The goal of boosting is to improve the generalization performance of weak (or base) learning algorithms by combining them in a certain way. The first algorithm of this type was discovered by Schapire [SCHAPIRE, R.E. (1990). The strength of weak learnability. Machine Learning...
Scale invariance and renormalization group
Scale invariance enabled the understanding of cooperative phenomena and the study of elementary interactions, such as phase transition phenomena, the Curie critical temperature and spin rearrangement in crystals. The renormalization group method, due to K. Wilson in 1971, allowed for the study of collective phenomena, using an iterative process from smaller scales to larger scales, leading to universal properties and the description of matter state transitions or long polymer behaviour; it also enabled to reconsider the quantum electrodynamic theory and its relations to time and distance scales
Invariants of quadratic differential forms
Wright, Joseph Edmund
2013-01-01
This classic monograph by a mathematician affiliated with Trinity College, Cambridge, offers a brief account of the invariant theory connected with a single quadratic differential form. Suitable for advanced undergraduates and graduate students of mathematics, it avoids unnecessary analysis and offers an accessible view of the field for readers unfamiliar with the subject.A historical overview is followed by considerations of the methods of Christoffel and Lie as well as Maschke's symbolic method and explorations of geometrical and dynamical methods. The final chapter on applications, which d
Quantum Weyl invariance and cosmology
Dabholkar, Atish
2016-09-01
Equations for cosmological evolution are formulated in a Weyl invariant formalism to take into account possible Weyl anomalies. Near two dimensions, the renormalized cosmological term leads to a nonlocal energy-momentum tensor and a slowly decaying vacuum energy. A natural generalization to four dimensions implies a quantum modification of Einstein field equations at long distances. It offers a new perspective on time-dependence of couplings and naturalness with potentially far-reaching consequences for the cosmological constant problem, inflation, and dark energy.
Quantum Weyl Invariance and Cosmology
Dabholkar, Atish
2015-01-01
Equations for cosmological evolution are formulated in a Weyl invariant formalism to take into account possible Weyl anomalies. Near two dimensions, the renormalized cosmological term leads to a nonlocal energy-momentum tensor and a slowly decaying vacuum energy. A natural generalization to four dimensions implies a quantum modification of Einstein field equations at long distances. It offers a new perspective on time-dependence of couplings and naturalness with potentially far-reaching consequences for the cosmological constant problem, inflation, and dark energy.
Magnetically Modified Asymmetric Supercapacitors Project
National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is for the development of an asymmetric supercapacitor that will have improved energy density and cycle...
Top Quark Forward-Backward Asymmetry in the Large Invariant Mass Region
Cheung, Kingman
2011-01-01
The forward-backward asymmetry (FBA) in top-pair production that was observed in 2008 gets a boost in a recent CDF publication. Not only has the FBA further been confirmed, but also distributional preferences are shown. Strikingly, the FBA is the most sizable in the large $M_{t\\bar t}$ invariant mass region and in the large rapidity difference $|\\Delta y|$ region. Here we used our previously proposed $t$-channel exchanged $W'$ boson to explain the new observations. We show that a new particle exchanged in the $t$-channel generically gives rise to such observations.