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Sample records for gruber cosmology prize

  1. Alan Guth and Andrei Linde win international cosmology award

    2004-01-01

    "Leading theoretical cosmologists Alan Guth, Weisskopf Professor of Physics at the Massachusetts Institute of Technology, and Andrei Linde, Professor of Physics at Stanford University, who played prominent roles in developing and refining the theory of cosmic inflation, have been selected by an international panel of experts to receive the 2004 Cosmology Prize of the Peter Gruber Foundation" (1 page).

  2. Meckel Gruber Syndrome: A Case Report

    Celal Devecioglu

    2004-01-01

    Full Text Available Meckel-Gruber syndrome is an autosomal recessive disordercharacterized by a combination of renal cysts and variably associatedfeatures including developmental anomalies of the central nervous system(typically encephalocele, hepatic ductal dysplasia and cysts, andpolydactyly. n this cases AFP levels are increases. Alternative names areMeckel Syndrome, Dysencephalia Splanchnocystica, Gruber Syndrome andMeckel – Gruber Syndrome. This study is presented to draw attention to theMeckel Gruber Syndrome which seen rarely, have high risk of reccurenceand antenathal determination of AFP levels and early diagnosis byultrasonographic screening can be confident.

  3. Cosmology

    Novikov, I.D.

    1979-01-01

    Progress made by this Commission over the period 1976-1978 is reviewed. Topics include the Hubble constant, deceleration parameter, large-scale distribution of matter in the universe, radio astronomy and cosmology, space astronomy and cosmology, formation of galaxies, physics near the cosmological singularity, and unconventional cosmological models. (C.F.)

  4. Meckel Gruber syndrome, A case report

    Aslan, Kiper; Külahçı Aslan, Elif; Orhan, Adnan; Atalay, Mehmet Aral

    2015-01-01

    ABSTRACT. Introduction: Meckel-Gruber Syndrome was first described by J R Meckel in 1822. It is an autosomal recessive disorder, and is caused by the failure of mesodermal induction. The typical triad of Meckel-Gruber Syndrome (MGS) involves meningo-encephalocele, polycystic kidneys and postaxial polydactyly. The worldwide incidence varies from 1 in 1.300 to 1 in 140.000 live births. Case: In this report, we present a case of MGS in which the diagnosis was made at 19 weeks of gestation based on ultrasonographic findings of the typical triad of the disease (encephalocele, polycystic kidneys, and polydactyly) These features were suggestive of the diagnosis of Meckel Gruber Syndrome (MGS). She had also placenta previa totalis. The patient was counselled regarding the lethal outcome of MGS. Unfortunately, the family did not approve the termination of pregnancy. At the 32nd week, she referred to hospital with complaints of vaginal bleeding and uterine contractions. An emergency cesarean section was perfomed due to plasental malposition. A 1380 gr, female fetus was delivered. First and 5th minute Apgar scores were 1 and 0, respectively. Consequently, the baby died after 45 minutes of neonatal resuscitation. Conclusıon: MGS is a lethal disorder. One cannot speak about survival of the fetus because of the pulmonary hypoplasia. The parents should be counseled about prognosis of the fetus and the outcome. Counselers should strictly give information about the recurrence risk for the next pregnancies. PMID:26037304

  5. Cosmology

    Contopoulos, G.; Kotsakis, D.

    1987-01-01

    An extensive first part on a wealth of observational results relevant to cosmology lays the foundation for the second and central part of the book; the chapters on general relativity, the various cosmological theories, and the early universe. The authors present in a complete and almost non-mathematical way the ideas and theoretical concepts of modern cosmology including the exciting impact of high-energy particle physics, e.g. in the concept of the ''inflationary universe''. The final part addresses the deeper implications of cosmology, the arrow of time, the universality of physical laws, inflation and causality, and the anthropic principle

  6. Cosmology

    García-Bellido, J

    2015-01-01

    In these lectures I review the present status of the so-called Standard Cosmological Model, based on the hot Big Bang Theory and the Inflationary Paradigm. I will make special emphasis on the recent developments in observational cosmology, mainly the acceleration of the universe, the precise measurements of the microwave background anisotropies, and the formation of structure like galaxies and clusters of galaxies from tiny primordial fluctuations generated during inflation.

  7. Cosmology

    Vittorio, Nicola

    2018-01-01

    Modern cosmology has changed significantly over the years, from the discovery to the precision measurement era. The data now available provide a wealth of information, mostly consistent with a model where dark matter and dark energy are in a rough proportion of 3:7. The time is right for a fresh new textbook which captures the state-of-the art in cosmology. Written by one of the world's leading cosmologists, this brand new, thoroughly class-tested textbook provides graduate and undergraduate students with coverage of the very latest developments and experimental results in the field. Prof. Nicola Vittorio shows what is meant by precision cosmology, from both theoretical and observational perspectives.

  8. Prize Draw

    Staff Association

    2014-01-01

      Prize draw Go Sport vouchers 393 members of the Staff Association participated in our free prize draw in July where they could win one of the thirty Go Sport vouchers of 50 euros. The thirty winners have been contacted and can come and collect their voucher from the Staff Association Secretariat.

  9. Meckel-Gruber syndrome: Report of two cases

    C Panduranga

    2012-01-01

    Full Text Available Meckel-Gruber syndrome (MKS is an autosomal recessive disorder, characterized by a combination of renal cysts and variably associated with features including developmental anomalies of the central nervous system (typically encephalocele, hepatic ductal dysplasia, cysts, and polydactyly. It is a rare syndrome with highest incidence in Gujarati Indians and Finnish population. We report two such cases of MKS in non-Gujarati Indian which were diagnosed by neonatal autopsy.

  10. MARTIN–GRUBER ANASTOMOSIS AND ITS CLINICAL IMPORTANCE

    I. G. Mikhaylyuk

    2015-01-01

    Full Text Available The communication between the median and ulnar nerves on the forearm, known as the Martin–Gruber anastomosis, is widespread in the general population. Despite the fact that this connection is described by anatomists in XVIII century, its importance has only recently been appreciated because of the widespread of the electrophysiological techniques in clinical practies. However, in the Russian literature aspects of its practical value described so far is not enough. This article deals with the prevalence of the anastomosis, its anatomical and electrophysiological classification, options innervation of muscles of the hand, is carried out through him, described electrophysiological methods and criteria for its diagnosis, including the collision technique, in healthy subjects and patients with lesions of the median and ulnar nerves, given its practical value. Such a course of nerve fibers through this anastomosis can have a significant impact on the clinical manifestations in patients with lesions of the median and ulnar nerves, as well as the results of an electrophysiological study. Martin–Gruber anastomosis provides variability innervation muscles of the hand, which can make it difficult topic diagnostic damage to the median and ulnar nerves, in addition, because of the connection between the nerves of the clinical presentation may not reflect the extent of their defeat: the hand muscles function can be preserved with full nerve damage or, conversely, significantly disrupted with minimal nerve lesions. Moreover, different electrophysiological findings on patients with pathology of the median or ulnar nerves in the conditions of functioning anastomosis may also complicate the interpretation of the clinical data. Thus, knowledge of the anatomy and physiology of the Martin–Gruber communication as necessary for the electrophysiologist for correct interpretation of the finding and the clinician to accurately diagnose the pathology of the median

  11. Clinical repercussions of Martin-Gruber anastomosis: anatomical study

    Cristina Schmitt Cavalheiro

    2016-04-01

    Full Text Available OBJECTIVE: The main objective of this study was to describe Martin-Gruber anastomosis anatomically and to recognize its clinical repercussions. METHOD: 100 forearms of 50 adult cadavers were dissected in an anatomy laboratory. The dissection was performed by means of a midline incision along the entire forearm and the lower third of the upper arm. Two flaps including skin and subcutaneous tissue were folded back on the radial and ulnar sides, respectively. RESULTS: Nerve communication between the median and ulnar nerves in the forearm (Martin-Gruber anastomosis was found in 27 forearms. The anastomosis was classified into six types: type I: anastomosis between the anterior interosseous nerve and the ulnar nerve (n = 9; type II: anastomosis between the anterior interosseous nerve and the ulnar nerve at two points (double anastomosis (n = 2; type III: anastomosis between the median nerve and the ulnar nerve (n = 4; type IV: anastomosis between branches of the median nerve and ulnar nerve heading toward the flexor digitorum profundus muscle of the fingers; these fascicles form a loop with distal convexity (n = 5; type V: intramuscular anastomosis (n = 5; and type VI: anastomosis between a branch of the median nerve to the flexor digitorum superficialis muscle and the ulnar nerve (n = 2. CONCLUSION: Knowledge of the anatomical variations relating to the innervation of the hand has great importance, especially with regard to physical examination, diagnosis, prognosis and surgical treatment. If these variations are not given due regard, errors and other consequences will be inevitable.

  12. Prizes reward high-energy physics

    2005-01-01

    The European Physical Society (EPS) has recognized four individuals and a collaboration for their work on charge-parity (CP) violation, gamma-ray astronomy, cosmology and outreach activities. Heinrich Wahl, formerly of CERN, and the NA31 collaboration share the 2005 High Energy and Particle Physics Prize for their work on CP violation at CERN (½ page)

  13. Meckel-Gruber Syndrome: Autopsy Based Approach to Diagnosis

    Asaranti Kar

    2016-01-01

    Full Text Available Meckel-Gruber syndrome (MGS is a rare lethal congenital malformation affecting 1 in 13,250-140,000 live births. The classical diagnostic triad comprises multicystic dysplastic kidneys, occipital encephalocele, and postaxial polydactyly. It can variably be associated with other malformations such as cleft lip and palate, pulmonary hypoplasia, hepatic fibrosis, and anomalies of central nervous system. A 20 weeks fetus was diagnosed as MGS with classical features along with many other congenital abnormalities such as microcephaly, microphthalmia, hypertelorism, cleft lip and palate, neonatal teeth, and the right side club foot which were detected only after doing autopsy. This case is reported because of its rarity emphasizing the importance of neonatal autopsy in every case of fetal death, especially where the antenatal diagnosis has not been made previously. A systematic approach to accurate diagnosis of MGS based on autopsy will be described here which can allow recurrence risk counseling and proper management in future pregnancies.

  14. Test Review: "Social Responsiveness Scale" by J. N. Constantino and C. P. Gruber

    Booker, Kimberly Wilson; Starling, LaRonda

    2011-01-01

    Published by Western Psychological Services, the "Social Responsiveness Scale" (SRS; Constantino & Gruber, 2005) was designed to assess abilities and deficits in social reciprocity. In particular, it was designed to assess subthreshold levels and severity of social impairment, a key marker of pervasive developmental disorders. The SRS may be…

  15. Nobel prizes 1975

    Braunbek, W.

    1975-01-01

    The 1975 Nobel prize in physics was awarded to A. Bohr, B. Mottelson and J. Rainwater for their new ideas about the structure of the heavier atomic nuclei and the foundation of the 'unified model' of these nuclei. (orig.) [de

  16. Awarding a Prize

    Moeran, Brian

    2013-01-01

    This article describes and analyses the selection and prize awarding processes for a biennial ceramics exhibition in Japan. Based on long-term fieldwork in the “art world” (Becker 1982) of contemporary Japanese ceramics, as well as on participant observation of the processes concerned, the article...... addresses and draws upon two sets of sociological writings: one concerned with prizes and awards; the other with evaluative practices....

  17. 2016 Lush Science Prize.

    McCann, Jenny; McCann, Terry

    2017-11-01

    The Lush Prize supports animal-free testing by awarding monetary prizes totalling £250,000 to the most effective projects and individuals who have been working toward the goal of replacing animals in product or ingredient safety testing. Prizes are awarded for developments in five strategic areas: Science; Lobbying; Training; Public Awareness; and Young Researchers. In the event of a major breakthrough leading to the replacement of animal tests in the area of 21st Century Toxicology, a Black Box Prize (equivalent to the entire annual fund of £250,000) is awarded. The Science Prize is awarded to the researchers whose work the judging panel believe has made the most significant contribution to the replacement of animal testing in the preceding year. This Background Paper outlines the research projects that were shortlisted and presented to the judging panel as potential candidates for the 2016 Lush Science Prize. This process involved reviewing recent work of the relevant scientific institutions and projects in this area, such as the OECD, CAAT, The Hamner Institutes, ECVAM, UK NC3Rs, and the US Tox21 Programme. Recent developments in toxicity testing research were also identified by searching for relevant published papers in the literature, and analysing abstracts from conferences focusing on animal replacement in toxicity testing that had been held in the preceding 12 months - for example the EUSAAT-Linz, Society of Toxicology, and SEURAT-1 conferences. 2017 FRAME.

  18. Light and electron microscopic study of Pelomyxa binucleata (Gruber, 1884) (Peloflagellatea, Pelobiontida)

    Frolov, Alexander; Chystjakova, Ludmila; Goodkov, Andrew

    2005-01-01

    Morphology of a pelobiont Pelomyxa binucleata (Gruber, 1884) has been studied using light and electron microscopy. The organisation of P. binucleata has been shown to differ from that of P. palustris, P. prima and P. corona. The cell surface of P. binucleata is represented by the plasma membrane with a thin but distinct layer of non structured glycocalyx. The ectoplasm, containing a network of fine fibrils, is separated from the endoplasm with a boundary layer of cisterns and reticulum channe...

  19. Syndrome de Meckel Gruber: à propos d'un cas rare | Itchimouh ...

    Le syndrome de Meckel Gruber est un syndrome poly malformatif rare, de transmission autosomique récessive, défini par d'encéphalocèle occipital, polydactylie et dysplasie kystique rénale. L'échographie constitue, à l'heure actuelle, le meilleur moyen de dépistage anténatal de cette poly malformation létale et sa ...

  20. A Nobel Prize winner visits CERN

    2007-01-01

    Nobel Prize-winning astrophysicist George Smoot visited CERN on 2 February with a message for particle physicists and cosmologists alike. After a tour of ATLAS and CMS, Smoot gave a talk to a packed Council Chamber about the connections between particle physics and cosmology, and how the two disciplines can help each other to find answers to their cosmic questions. Smoot's group at Lawrence Berkeley National Laboratory is currently working on the development of the Max Planck Surveyor, the next generation of satellite to study cosmic microwave background anisotropy, which will teach us about how our universe was formed.

  1. Wolf prize in physics

    Piran, Tsvi

    2016-01-01

    The Wolf Foundation began its activities in 1976, with an initial endowment donated by the Wolf family. Within a very short period of time after its initiation, the Wolf prize has become one of the major signs for recognition of scientific achievements and excellence. This volume is devoted to a selection of Wolf Prize laureates in Physics and each has included two respective major publications as well as a commentary written by the laureate describing his scientific career. Readers around the world are provided a unique opportunity to get a glimpse of how scientific processes work in physics, and to comprehend how these laureates have left an indelible imprint on scientific history.

  2. Citations Prize 2013

    Cherry, Simon; Ruffle, Jon

    2014-06-01

    Physics in Medicine and Biology (PMB) awards its 'Citations Prize' to the authors of the original research paper that has received the most citations in the preceding five years (according to the Institute for Scientific Information (ISI)). The lead author of the winning paper is presented with the Rotblat Medal (named in honour of Professor Sir Joseph Rotblat, a Nobel Prize winner who also was the second—and longest serving—Editor of PMB, from 1961-1972). The winner of the 2013 Citations Prize for the paper which has received the most citations in the previous five years (2008-2012) is Figure. Figure. Four of the prize winning authors. From left to right: Thomas Istel (Philips), Jens-Peter Schlomka (with medal, MorphoDetection), Ewald Roessl (Philips), and Gerhard Martens (Philips). Title: Experimental feasibility of multi-energy photon-counting K-edge imaging in pre-clinical computed tomography Authors: Jens Peter Schlomka1, Ewald Roessl1, Ralf Dorscheid2, Stefan Dill2, Gerhard Martens1, Thomas Istel1, Christian Bäumer3, Christoph Herrmann3, Roger Steadman3, Günter Zeitler3, Amir Livne4 and Roland Proksa1 Institutions: 1 Philips Research Europe, Sector Medical Imaging Systems, Hamburg, Germany 2 Philips Research Europe, Engineering & Technology, Aachen, Germany 3 Philips Research Europe, Sector Medical Imaging Systems, Aachen, Germany 4 Philips Healthcare, Global Research and Advanced Development, Haifa, Israel Reference: Schlomka et al 2008 Phys. Med. Biol. 53 4031-47 This paper becomes the first to win both this citations prize and also the PMB best paper prize (The Roberts Prize), which it won for the year 2008. Discussion of the significance of the winning paper can be found in this medicalphysicsweb article from the time of the Roberts Prize win (http://medicalphysicsweb.org/cws/article/research/39907). The author's enthusiasm for their prototype spectral CT system has certainly been reflected in the large number of citations the paper subsequently has

  3. Nobel Prize ceremony 2013

    2013-01-01

    On 10 December 2013 particle physics took central stage at the Nobel ceremony in Stockholm. Among the invitees were Fabiola Gianotti, former ATLAS spokesperson, Joseph Incandela, CMS Spokesperson, and CERN theorist Luis Alvarez-Gaume. They share their feelings of the memorable day with us.   Overview of the 2013 Nobel Prize Award Ceremony at the Stockholm Concert Hall. © Nobel Media AB 2013. Photo: Alex Ljungdahl. Fabiola Gianotti and Joe Incandela, at the Nobel Banquet in the Stockholm City Hall.   "It was an honour and a thrill for us to attend such a memorable Nobel prize ceremony and we are very grateful to Peter Higgs for having included us among his invited guests. The ceremony held some special moments for the LHC. In his speech prior to the award of the Nobel prize to Francois Englert and Peter Higgs by King Carl XVI Gustaf of Sweden, Lars Brink (Chair of the Physics Nobel Prize Committee) stressed the importance of the results from the LHC exper...

  4. The 2010 Broad Prize

    Education Digest: Essential Readings Condensed for Quick Review, 2011

    2011-01-01

    A new data analysis, based on data collected as part of The Broad Prize process, provides insights into which large urban school districts in the United States are doing the best job of educating traditionally disadvantaged groups: African-American, Hispanics, and low-income students. Since 2002, The Eli and Edythe Broad Foundation has awarded The…

  5. The Abel Prize

    Holden, Helge

    2010-01-01

    Presents the winners of the first five Abel Prizes in mathematics: 2003 - Jean-Pierre Serre; 2004 - Sir Michael Atiyah and Isadore Singer; 2005 - Peter D Lax; 2006 - Lennart Carleson; and 2007 - S R Srinivasa Varadhan. This book provides an autobiography or an interview, a curriculum vitae, and a complete bibliography of each laureate

  6. Citations Prize 2009 Citations Prize 2009

    Webb, Steve; Harris, Simon

    2009-12-01

    Physics in Medicine & Biology (PMB) awards its 'Citations Prize' to the authors of the original research paper that has received the most citations in the preceding five years (according to the Institute for Scientific Information (ISI)). The lead author of the winning paper is presented with the Rotblat Medal (named in honour of Professor Sir Joseph Rotblat who was the second—and longest serving—Editor of PMB, from 1961-1972). The winning co-authors each receive a certificate. Photograph of the 2009 Citations Prize winners Some of the winning authors with their certificates, and Christian Morel with the Rotblat Medal, at the award ceremony in Orsay, near Paris. From left to right are Corinne Groiselle, Lydia Maigne, David Brasse, Irène Buvat, Dimitris Visvikis, Giovanni Santin, Uwe Pietrzyk, Pierre-François Honore, Christian Morel, Sébastien Jan and Arion Chatziioannou. The winner of the 2009 Citations Prize for the paper which has received the most citations in the previous 5 years (2004-2008) is GATE: a simulation toolkit for PET and SPECT Authors: S Jan, G Santin, D Strul, S Staelens, K Assié, D Autret, S Avner, R Barbier, M Bardiès, P M Bloomfield, D Brasse, V Breton, P Bruyndonckx, I Buvat, A F Chatziioannou, Y Choi, Y H Chung, C Comtat, D Donnarieix, L Ferrer, S J Glick, C J Groiselle, D Guez, P-F Honore, S Kerhoas-Cavata, A S Kirov, V Kohli, M Koole, M Krieguer, D J van der Laan, F Lamare, G Largeron, C Lartizien, D Lazaro, M C Maas, L Maigne, F Mayet, F Melot, C Merheb, E Pennacchio, J Perez, U Pietrzyk, F R Rannou, M Rey, D R Schaart, C R Schmidtlein, L~Simon, T Y Song, J-M Vieira, D Visvikis, R Van de Walle, E Wieörs and C Morel Reference: S Jan et al 2004 Phys. Med. Biol. 49 4543-61 Since its publication in 2004 this article has received over 200 citations. This extremely high figure is a testament to the great influence and usefulness of the work to the nuclear medicine community. More discussion of the winning paper can be found on

  7. Entrapment of the Martin-Gruber branch of median nerve in the forearm

    Anu Vinod Ranade

    2016-07-01

    Full Text Available We report a rare case of a dual neuro-vascular variation, which was observed in the right extremity of male cadaver. About an inch inferior to the elbow joint, three branches arose from the median nerve. These were the anterior interosseous branch, a Martin-Gruber branch (MGB and a muscular branch. The MGB coursed infero-medially to join with the ulnar nerve by running posterior to the ulnar artery. It was surprising to observe that the MGB passed between the ulnar artery and its venae comitantes. There was an acute angulation of the MGB here, suggesting entrapment at this site.

  8. Anastomosis Martin-Gruber: Aspectos anatómicos y electrofisiológicos Martin-Gruber Anastomosis: Anatomical and electrophysiological issues

    Esperanza Herrera

    2009-08-01

    Full Text Available La anastomosis de Martin Gruber (AMG es una de las variaciones anatómicas más frecuentes que consiste en la contribución de axones motores desde el nervio mediano hacia el ulnar en el antebrazo. Factores filogenéticos y genéticos se asocian con la aparición de la AMG. Entre tanto, otros factores como género, raza o lateralidad no parecen tener importancia en la aparición de la rama comunicante. Las clasificaciones de la AMG han sido establecidas según los hallazgos anatómicos, electrofisiológicos e histológicos y también según el lugar de origen y destino de la anastomosis. El objetivo de este artículo es revisar los factores asociados a la presencia de la AMG, así como las descripciones y clasificaciones anatómicas y electrofisiológicas. Esta revisión aporta información relevante para el reconocimiento de los patrones clásico y variante de inervación de la musculatura intrínseca de la mano. Dicho reconocimiento permite diagnosticar e intervenir apropiadamente las alteraciones de los nervios periféricos de la extremidad superior. Salud UIS 2009; 41: 157-168The Martin Gruber Anastomosis (MGA is one of the most common anatomical variants of the upper limb, which consists of motor axons crossing through the forearm from the median nerve to the ulnar nerve. Phylogenetic and hereditary factors have been associated whit the MGA. However, gender, race, or laterality, do not seem to have importance in the appearance of the communicating branch. The MGA has been categorized according to findings in anatomy, electrophysiology and histology, in relation to the source and destination of the communicating branch. The aim of this article is to review the factors related to the presence of MGA, as well as the descriptions and classifications according to anatomy and electrophysiology. This revision contributes with important information relevant to the recognition of differences between the classic pattern and the variant pattern of the

  9. Vision and the Nobel Prize.

    Morais, Fábio Barreto

    2018-04-01

    The Nobel Prize is the world's foremost honor for scientific advances in medicine and other areas. Founded by Alfred Nobel, the prizes have been awarded annually since 1901. We reviewed the literature on persons who have won or competed for this prize in subjects related to vision and ophthalmology. The topics were divided into vision physiology, diagnostic and therapeutic methods, disease mechanism, and miscellaneous categories. Allvar Gullstrand is the only ophthalmologist to win a Nobel Prize; he is also the only one to receive it for work in ophthalmology. Other ophthalmologists that have been nominated were Hjalmar Schiötz (tonometer), Karl Koller (topical anesthesia), and Jules Gonin (retinal detachment). Other scientists have won the prize for eye-related research: Ragnar Granit, Haldan Hartline and George Wald (chemistry and physiology of vision), and David Hubel and Torsten Wiesel (processing in the visual system). Peter Medawar is the only person born in Brazil to have won the Nobel Prize.

  10. EPS Young Physicist Prize - CORRECTION

    2009-01-01

    The original text for the article 'Prizes aplenty in Krakow' in Bulletin 30-31 assigned the award of the EPS HEPP Young Physicist Prize to Maurizio Pierini. In fact he shared the prize with Niki Saoulidou of Fermilab, who was rewarded for her contribution to neutrino physics, as the article now correctly indicates. We apologise for not having named Niki Saoulidou in the original article.

  11. IEEE Prize for Lucio Rossi

    IEEE Council on Superconductivity

    2007-01-01

    Lucio Rossi receives his prize from John Spargo, Chairman of the IEEE Council on Superconductivity (left), and Martin Nisenoff, Chairman of the Council on Superconductivity's Awards Committee (right).

  12. Mathematical cosmology

    Wainwright, J.

    1990-01-01

    The workshop on mathematical cosmology was devoted to four topics of current interest. This report contains a brief discussion of the historical background of each topic and a concise summary of the content of each talk. The topics were; the observational cosmology program, the cosmological perturbation program, isotropic singularities, and the evolution of Bianchi cosmologies. (author)

  13. Theoretical cosmology

    Raychaudhuri, A.K.

    1979-01-01

    The subject is covered in chapters, entitled; introduction; Newtonian gravitation and cosmology; general relativity and relativistic cosmology; analysis of observational data; relativistic models not obeying the cosmological principle; microwave radiation background; thermal history of the universe and nucleosynthesis; singularity of cosmological models; gravitational constant as a field variable; cosmological models based on Einstein-Cartan theory; cosmological singularity in two recent theories; fate of perturbations of isotropic universes; formation of galaxies; baryon symmetric cosmology; assorted topics (including extragalactic radio sources; Mach principle). (U.K.)

  14. Meckel-Gruber Syndrome : a population-based study on prevalence, prenatal diagnosis, clinical features, and survival in Europe

    Barisic, Ingeborg; Boban, Ljubica; Loane, Maria; Garne, Ester; Wellesley, Diana; Calzolari, Elisa; Dolk, Helen; Addor, Marie-Claude; Bergman, Jorieke E. H.; Braz, Paula; Draper, Elizabeth S.; Haeusler, Martin; Khoshnood, Babak; Klungsoyr, Kari; Pierini, Anna; Queisser-Luft, Annette; Rankin, Judith; Rissmann, Anke; Verellen-Dumoulin, Christine

    Meckel-Gruber Syndrome is a rare autosomal recessive lethal ciliopathy characterized by the triad of cystic renal dysplasia, occipital encephalocele and postaxial polydactyly. We present the largest population-based epidemiological study to date using data provided by the European Surveillance of

  15. Nobel Prize in Physiology or Medicine

    ... Educational - Medicine Prize Related The Nobel Prize in Physiology or Medicine has been awarded to people and ... this page MLA style: "The Nobel Prize in Physiology or Medicine – Educational". Nobelprize.org. Nobel Media ...

  16. Cosmology comes of age

    2006-01-01

    This year's Nobel prize is welcome recognition for cosmology. Back in the 1960s, according to Paul Davies' new book The Goldilocks Enigma (see 'Seeking anthropic answers' in this issue), cynics used to quip that there is 'speculation, speculation squared - and cosmology'. Anyone trying to understand the origin and fate of the universe was, in other words, dealing with questions that were simply impractical - or even impossible - to answer. But that has all changed with the development of new telescopes, satellites and data-processing techniques - to the extent that cosmology is now generally viewed as a perfectly acceptable branch of science. If anyone was in any doubt of cosmology's new status, the Royal Swedish Academy of Sciences last month gave the subject welcome recognition with the award of this year's Nobel prize to John Mather and George Smoot (see pp6-7; print version only). The pair were the driving force behind the COBE satellite that in 1992 produced the now famous image of the cosmic microwave background. The mission's data almost certainly proved that the universe started with a Big Bang, while tiny fluctuations in the temperature signal between different parts of the sky were shown to be the seeds of the stars and galaxies we see today. These results are regarded by many as the start of a new era of 'precision cosmology'. But for cosmologists, the job is far from over. There are still massive holes in our understanding of the cosmos, notably the nature of dark matter and dark energy, which together account for over 95% of the total universe. Indeed, some regard dark energy and matter as just ad hoc assumptions needed to fit the data. (Hypothetical particles called 'axions' are one possible contender for dark matter (see pp20-23; print version only), but don't bet your house on it.) Some physicists even think it makes more sense to adjust Newtonian gravity rather than invoke dark matter. But the notion that cosmology is in crisis, as argued by some

  17. MRI of the tibioastragalus anticus of Gruber muscle: a rare accessory muscle and normal anatomical variant

    Berkowitz, Yaron; Amiras, Dimitri [Imperial College Healthcare NHS Trust, London (United Kingdom); St Mary' s Hospital, Imaging Department, QEQM, London (United Kingdom); Mushtaq, Nadeem [Imperial College Healthcare NHS Trust, London (United Kingdom)

    2016-06-15

    We present the case of a 31-year-old man who sustained a hyperplantar flexion injury of his right ankle, and was evaluated using computed tomography and MRI to assess for osseous and ligamentous injury. The MRI and CT studies demonstrated a tibioastragalus anticus of Gruber (TAAG) muscle in the lower limb's anterior compartment. To our knowledge, the imaging of this muscle has not been previously described. The TAAG muscle arises from the lower third of the anterolateral tibia and the interosseous membrane. Its tendon passes laterally, deep to the tibialis anterior and extensor hallucis longus tendons, and inserts onto the anterior superolateral neck of the talus in a fan-like manner. Knowledge and recognition of this tendon are important for both diagnostic accuracy and surgical planning, and could potentially be used as a tendon transfer or graft in the appropriate clinical setting. The presence of this accessory muscle should not be confused with a pathological condition. (orig.)

  18. Nobel Prizes: Contributions to Cardiology

    Mesquita, Evandro Tinoco; Marchese, Luana de Decco; Dias, Danielle Warol; Barbeito, Andressa Brasil; Gomes, Jonathan Costa; Muradas, Maria Clara Soares; Lanzieri, Pedro Gemal; Gismondi, Ronaldo Altenburg

    2015-01-01

    The Nobel Prize was created by Alfred Nobel. The first prize was awarded in 1901 and Emil Adolf von Behring was the first laureate in medicine due to his research in diphtheria serum. Regarding cardiology, Nobel Prize’s history permits a global comprehension of progress in pathophysiology, diagnosis and therapeutics of various cardiac diseases in last 120 years. The objective of this study was to review the major scientific discoveries contemplated by Nobel Prizes that contributed to cardiology. In addition, we also hypothesized why Carlos Chagas, one of our most important scientists, did not win the prize in two occasions. We carried out a non-systematic review of Nobel Prize winners, selecting the main studies relevant to heart diseaseamong the laureates. In the period between 1901 and 2013, 204 researches and 104 prizes were awarded in Nobel Prize, of which 16 (15%) studies were important for cardiovascular area. There were 33 (16%) laureates, and two (6%) were women. Fourteen (42%) were American, 15 (45%) Europeans and four (13%) were from other countries. There was only one winner born in Brazil, Peter Medawar, whose career was all in England. Reviewing the history of the Nobel Prize in physiology or medicine area made possible to identify which researchers and studies had contributed to advances in the diagnosis, prevention and treatment of cardiovascular diseases. Most winners were North Americans and Europeans, and male

  19. Nobel Prizes: Contributions to Cardiology

    Mesquita, Evandro Tinoco; Marchese, Luana de Decco; Dias, Danielle Warol; Barbeito, Andressa Brasil; Gomes, Jonathan Costa; Muradas, Maria Clara Soares; Lanzieri, Pedro Gemal; Gismondi, Ronaldo Altenburg, E-mail: ronaldo@floralia.com.br [Universidade Federal Fluminense, Niterói, RJ (Brazil)

    2015-08-15

    The Nobel Prize was created by Alfred Nobel. The first prize was awarded in 1901 and Emil Adolf von Behring was the first laureate in medicine due to his research in diphtheria serum. Regarding cardiology, Nobel Prize’s history permits a global comprehension of progress in pathophysiology, diagnosis and therapeutics of various cardiac diseases in last 120 years. The objective of this study was to review the major scientific discoveries contemplated by Nobel Prizes that contributed to cardiology. In addition, we also hypothesized why Carlos Chagas, one of our most important scientists, did not win the prize in two occasions. We carried out a non-systematic review of Nobel Prize winners, selecting the main studies relevant to heart diseaseamong the laureates. In the period between 1901 and 2013, 204 researches and 104 prizes were awarded in Nobel Prize, of which 16 (15%) studies were important for cardiovascular area. There were 33 (16%) laureates, and two (6%) were women. Fourteen (42%) were American, 15 (45%) Europeans and four (13%) were from other countries. There was only one winner born in Brazil, Peter Medawar, whose career was all in England. Reviewing the history of the Nobel Prize in physiology or medicine area made possible to identify which researchers and studies had contributed to advances in the diagnosis, prevention and treatment of cardiovascular diseases. Most winners were North Americans and Europeans, and male.

  20. 2013 Physics Nobel Prize

    Orloff, J.

    2013-01-01

    The 2013 Physics Nobel Prize was awarded conjointly to Englert F. and Higgs, P.W. for the theoretical discovery of a mechanism that contribute to our understanding of the origin of the mass of subatomic particles and which was recently confirmed by the discovery of the predicted Higgs boson in the ATLAS and CMS experiments at the LHC. The Brout-Englert-Higgs (BEH) mechanism allows the conciliation of finite range interaction and then non-null mass with symmetry through the concept of spontaneous symmetry breaking. As mass and couplings are relativist invariants, they stay unchanged in the rotation of the space for instance, the BEH field must be too and as a consequence must be a scalar field associated with a null spin particle called the Higgs boson. As the BEH mechanism explains the mass of elementary particles, it gives no hint about the reason of the broad range of particle masses we observe. (A.C.)

  1. Mathematical cosmology

    Landsberg, P.T.; Evans, D.A.

    1977-01-01

    The subject is dealt with in chapters, entitled: cosmology -some fundamentals; Newtonian gravitation - some fundamentals; the cosmological differential equation - the particle model and the continuum model; some simple Friedmann models; the classification of the Friedmann models; the steady-state model; universe with pressure; optical effects of the expansion according to various theories of light; optical observations and cosmological models. (U.K.)

  2. Observable cosmology and cosmological models

    Kardashev, N.S.; Lukash, V.N.; Novikov, I.D.

    1987-01-01

    Modern state of observation cosmology is briefly discussed. Among other things, a problem, related to Hibble constant and slowdown constant determining is considered. Within ''pancake'' theory hot (neutrino) cosmological model explains well the large-scale structure of the Universe, but does not explain the galaxy formation. A cold cosmological model explains well light object formation, but contradicts data on large-scale structure

  3. Modern Cosmology

    Zhang Yuan Zhong

    2002-01-01

    This book is one of a series in the areas of high-energy physics, cosmology and gravitation published by the Institute of Physics. It includes courses given at a doctoral school on 'Relativistic Cosmology: Theory and Observation' held in Spring 2000 at the Centre for Scientific Culture 'Alessandro Volta', Italy, sponsored by SIGRAV-Societa Italiana di Relativita e Gravitazione (Italian Society of Relativity and Gravitation) and the University of Insubria. This book collects 15 review reports given by a number of outstanding scientists. They touch upon the main aspects of modern cosmology from observational matters to theoretical models, such as cosmological models, the early universe, dark matter and dark energy, modern observational cosmology, cosmic microwave background, gravitational lensing, and numerical simulations in cosmology. In particular, the introduction to the basics of cosmology includes the basic equations, covariant and tetrad descriptions, Friedmann models, observation and horizons, etc. The ...

  4. Haagen-Smit Prize 2015

    2016-01-01

    The Executive Editors and the Publisher of Atmospheric Environment take great pleasure in announcing the 2015 ''Haagen-Smit Prize;, designed to recognize outstanding papers published in Atmospheric Environment. The Prize is named in honor of Prof. Arie Jan Haagen-Smit, a pioneer in the field of air pollution and one of the first editors of the International Journal of Air Pollution, a predecessor to Atmospheric Environment.

  5. Haagen-Smit Prize 2014

    2015-02-01

    The Executive Editors and the Publisher of Atmospheric Environment take great pleasure in announcing the 2014 ''Haagen-Smit Prize", designed to recognize outstanding papers published in Atmospheric Environment. The Prize is named in honor of Prof. Arie Jan Haagen-Smit, a pioneer in the field of air pollution and one of the first editors of the International Journal of Air Pollution, a predecessor to Atmospheric Environment.

  6. Haagen-Smit Prize 2016

    Singh, Hanwant

    2017-03-01

    The Executive Editors and the Publisher of Atmospheric Environment take great pleasure in announcing the 2016 "Haagen-Smit Prize", designed to recognize outstanding papers published in Atmospheric Environment. The Prize is named in honor of Prof. Arie Jan Haagen-Smit, a pioneer in the field of air pollution and one of the first editors of the International Journal of Air Pollution, a predecessor to Atmospheric Environment.

  7. Nobel prize awards in radiochemistry

    Adloff, J.P.

    2012-01-01

    In 1996 the Editors of Radiochimica Acta brought out a special volume of the journal to celebrate the hundredth anniversary of the discovery of radioactivity. On the occasion of the 50 th anniversary of Radiochimica Acta, which follows closely upon the centenary of Marie Curie's second Nobel Prize in 1911, the author has the privilege to informally review 'Radiochemistry and Nobel Prize Awards', including discoveries of radioelements and new fields in chemistry based on radiochemical methods. (orig.)

  8. Precision Cosmology

    Jones, Bernard J. T.

    2017-04-01

    Preface; Notation and conventions; Part I. 100 Years of Cosmology: 1. Emerging cosmology; 2. The cosmic expansion; 3. The cosmic microwave background; 4. Recent cosmology; Part II. Newtonian Cosmology: 5. Newtonian cosmology; 6. Dark energy cosmological models; 7. The early universe; 8. The inhomogeneous universe; 9. The inflationary universe; Part III. Relativistic Cosmology: 10. Minkowski space; 11. The energy momentum tensor; 12. General relativity; 13. Space-time geometry and calculus; 14. The Einstein field equations; 15. Solutions of the Einstein equations; 16. The Robertson-Walker solution; 17. Congruences, curvature and Raychaudhuri; 18. Observing and measuring the universe; Part IV. The Physics of Matter and Radiation: 19. Physics of the CMB radiation; 20. Recombination of the primeval plasma; 21. CMB polarisation; 22. CMB anisotropy; Part V. Precision Tools for Precision Cosmology: 23. Likelihood; 24. Frequentist hypothesis testing; 25. Statistical inference: Bayesian; 26. CMB data processing; 27. Parametrising the universe; 28. Precision cosmology; 29. Epilogue; Appendix A. SI, CGS and Planck units; Appendix B. Magnitudes and distances; Appendix C. Representing vectors and tensors; Appendix D. The electromagnetic field; Appendix E. Statistical distributions; Appendix F. Functions on a sphere; Appendix G. Acknowledgements; References; Index.

  9. Observational cosmology

    Sanders, RH; Papantonopoulos, E

    2005-01-01

    I discuss the classical cosmological tests, i.e., angular size-redshift, flux-redshift, and galaxy number counts, in the light of the cosmology prescribed by the interpretation of the CMB anisotropies. The discussion is somewhat of a primer for physicists, with emphasis upon the possible systematic

  10. Nobel prize awards in radiochemistry

    Adloff, J.P. [Strasbourg Univ. (France)

    2012-07-01

    In 1996 the Editors of Radiochimica Acta brought out a special volume of the journal to celebrate the hundredth anniversary of the discovery of radioactivity. On the occasion of the 50{sup th} anniversary of Radiochimica Acta, which follows closely upon the centenary of Marie Curie's second Nobel Prize in 1911, the author has the privilege to informally review 'Radiochemistry and Nobel Prize Awards', including discoveries of radioelements and new fields in chemistry based on radiochemical methods. (orig.)

  11. Safety Day Prize Competition: results and answers

    HSE Unit

    2014-01-01

    The three winners of the Safety Day Prize Competition are...   • 1st Prize: Fernando LEITE PEREIRA – smoke detector • 2nd Prize: Thomas DE BORTOLI – water filter jug • 3rd Prize: Matti KALLIOKOSKI – safety goggles Please see the image below for the answers to the questionnaire. If you have any questions regarding the Safety Day, please contact: safety.communication@cern.ch. And again, thank you to all the participants!

  12. Interview with Abel Prize Recipient Lennart Carleson

    Raussen, Martin; Skau, Christian

    2008-01-01

    Lennart Carleson was the recipient of the 2006 Abel Prize. On May 22, 2006, prior to the Abel Prize celebration in Oslo, Carleson was interviewed. The interview was later shown on Norwegian television.......Lennart Carleson was the recipient of the 2006 Abel Prize. On May 22, 2006, prior to the Abel Prize celebration in Oslo, Carleson was interviewed. The interview was later shown on Norwegian television....

  13. Meckel-Gruber Syndrome: a population-based study on prevalence, prenatal diagnosis, clinical features, and survival in Europe

    Barisic, Ingeborg; Boban, Ljubica; Loane, Maria

    2015-01-01

    Meckel-Gruber Syndrome is a rare autosomal recessive lethal ciliopathy characterized by the triad of cystic renal dysplasia, occipital encephalocele and postaxial polydactyly. We present the largest population-based epidemiological study to date using data provided by the European Surveillance of...... diagnosis is important for timely counseling of affected couples regarding the option of pregnancy termination and prenatal genetic testing in future pregnancies.European Journal of Human Genetics advance online publication, 3 September 2014; doi:10.1038/ejhg.2014.174....

  14. Nobel Prize in Physics 2006

    Administrator

    B ut every once in a w hile,these prizes are also given to team lead- ers w ho spearhead a large collaboration w hich .... saying that `the w hole universe is expanding' w ith dis- .... body form was a ¯rm prediction from big bang m odel, it w as im ...

  15. Nobel Prize in Chemistry-1997

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 2. Nobel Prize in Chemistry – 1997 The Story of Two Extra-ordinary Enzymes. Subramania Ranganathan. General Article Volume 3 Issue 2 February 1998 pp 45-52 ...

  16. Nobel Prize Honors Autophagy Discovery.

    2016-12-01

    Japanese cell biologist Yoshinori Ohsumi, PhD, was awarded this year's Nobel Prize in Physiology or Medicine for his discovery of autophagy. His groundbreaking studies in yeast cells illuminated how cells break down and recycle damaged material, a process that is critical to the survival of both normal cells and some cancer cells. ©2016 American Association for Cancer Research.

  17. Supernova cosmology

    Leibundgut, B.

    2005-01-01

    Supernovae have developed into a versatile tool for cosmology. Their impact on the cosmological model has been profound and led to the discovery of the accelerated expansion. The current status of the cosmological model as perceived through supernova observations will be presented. Supernovae are currently the only astrophysical objects that can measure the dynamics of the cosmic expansion during the past eight billion years. Ongoing experiments are trying to determine the characteristics of the accelerated expansion and give insight into what might be the physical explanation for the acceleration. (author)

  18. Neutrino cosmology

    Berstein, J.

    1984-01-01

    These lectures offer a self-contained review of the role of neutrinos in cosmology. The first part deals with the question 'What is a neutrino.' and describes in a historical context the theoretical ideas and experimental discoveries related to the different types of neutrinos and their properties. The basic differences between the Dirac neutrino and the Majorana neutrino are pointed out and the evidence for different neutrino 'flavours', neutrino mass, and neutrino oscillations is discussed. The second part summarizes current views on cosmology, particularly as they are affected by recent theoretical and experimental advances in high-energy particle physics. Finally, the close relationship between neutrino physics and cosmology is brought out in more detail, to show how cosmological constraints can limit the various theoretical possibilities for neutrinos and, more particularly, how increasing knowledge of neutrino properties can contribute to our understanding of the origin, history, and future of the Universe. The level is that of the beginning graduate student. (orig.)

  19. Qualitative cosmology

    Khalatnikov, I.M.; Belinskij, V.A.

    1984-01-01

    Application of the qualitative theory of dynamic systems to analysis of homogeneous cosmological models is described. Together with the well-known cases, requiring ideal liquid, the properties of cosmological evolution of matter with dissipative processes due to viscosity are considered. New cosmological effects occur, when viscosity terms being one and the same order with the rest terms in the equations of gravitation or even exceeding them. In these cases the description of the dissipative process by means of only two viscosity coefficients (volume and shift) may become inapplicable because all the rest decomposition terms of dissipative addition to the energy-momentum in velocity gradient can be large application of equations with hydrodynamic viscosty should be considered as a model of dissipative effects in cosmology

  20. Neutrino cosmology

    Lesgourgues, Julien; Miele, Gennaro; Pastor, Sergio

    2013-01-01

    The role that neutrinos have played in the evolution of the Universe is the focus of one of the most fascinating research areas that has stemmed from the interplay between cosmology, astrophysics and particle physics. In this self-contained book, the authors bring together all aspects of the role of neutrinos in cosmology, spanning from leptogenesis to primordial nucleosynthesis, their role in CMB and structure formation, to the problem of their direct detection. The book starts by guiding the reader through aspects of fundamental neutrino physics, such as the standard cosmological model and the statistical mechanics in the expanding Universe, before discussing the history of neutrinos in chronological order from the very early stages until today. This timely book will interest graduate students and researchers in astrophysics, cosmology and particle physics, who work with either a theoretical or experimental focus.

  1. Modern cosmology

    Zeldovich, Y.B.

    1983-01-01

    This paper fives a general review of modern cosmology. The following subjects are discussed: hot big bang and periodization of the evolution; Hubble expansion; the structure of the universe (pancake theory); baryon asymmetry; inflatory universe. (Auth.)

  2. Highlights from e-EPS: the 2015 EPS High Energy Physics Prize winners

    Thomas Lohse, e-EPS News

    2015-01-01

    The EPS High Energy Physics Division announces the winners of its 2015 prizes, which will be awarded at the Europhysics Conference on High-Energy Physics (EPS-HEP 2015), Vienna (Austria) 22−29 July. Many people from CERN were among the winners.   The 2015 High Energy and Particle Physics Prize, for an outstanding contribution to High Energy Physics, is awarded to James D. Bjorken “for his prediction of scaling behaviour in the structure of the proton that led to a new understanding of the b interaction”, and to Guido Altarelli, Yuri L. Dokshitzer, Lev Lipatov, and Giorgio Parisi “for developing a probabilistic field theory framework for the dynamics of quarks and gluons, enabling a quantitative understanding of high-energy collisions involving hadrons”. The 2015 Giuseppe and Vanna Cocconi Prize, for an outstanding contribution to Particle Astrophysics and Cosmology in the past 15 years, is awarded to Francis Halzen “for his visiona...

  3. Modern Cosmology

    Zhang Yuanzhong

    2002-06-21

    This book is one of a series in the areas of high-energy physics, cosmology and gravitation published by the Institute of Physics. It includes courses given at a doctoral school on 'Relativistic Cosmology: Theory and Observation' held in Spring 2000 at the Centre for Scientific Culture 'Alessandro Volta', Italy, sponsored by SIGRAV-Societa Italiana di Relativita e Gravitazione (Italian Society of Relativity and Gravitation) and the University of Insubria. This book collects 15 review reports given by a number of outstanding scientists. They touch upon the main aspects of modern cosmology from observational matters to theoretical models, such as cosmological models, the early universe, dark matter and dark energy, modern observational cosmology, cosmic microwave background, gravitational lensing, and numerical simulations in cosmology. In particular, the introduction to the basics of cosmology includes the basic equations, covariant and tetrad descriptions, Friedmann models, observation and horizons, etc. The chapters on the early universe involve inflationary theories, particle physics in the early universe, and the creation of matter in the universe. The chapters on dark matter (DM) deal with experimental evidence of DM, neutrino oscillations, DM candidates in supersymmetry models and supergravity, structure formation in the universe, dark-matter search with innovative techniques, and dark energy (cosmological constant), etc. The chapters about structure in the universe consist of the basis for structure formation, quantifying large-scale structure, cosmic background fluctuation, galaxy space distribution, and the clustering of galaxies. In the field of modern observational cosmology, galaxy surveys and cluster surveys are given. The chapter on gravitational lensing describes the lens basics and models, galactic microlensing and galaxy clusters as lenses. The last chapter, 'Numerical simulations in cosmology', deals with spatial and

  4. Current cosmology

    Zeldovich, Ya.

    1984-01-01

    The knowledge is summed up of contemporary cosmology on the universe and its development resulting from a great number of highly sensitive observations and the application of contemporary physical theories to the entire universe. The questions are assessed of mass density in the universe, the structure and origin of the universe, its baryon asymmetry and the quantum explanation of the origin of the universe. Physical problems are presented which should be resolved for the future development of cosmology. (Ha)

  5. Particle cosmology

    CERN. Geneva

    2007-01-01

    The understanding of the Universe at the largest and smallest scales traditionally has been the subject of cosmology and particle physics, respectively. Studying the evolution of the Universe connects today's large scales with the tiny scales in the very early Universe and provides the link between the physics of particles and of the cosmos. This series of five lectures aims at a modern and critical presentation of the basic ideas, methods, models and observations in today's particle cosmology.

  6. Nobel prizes that changed medicine

    2012-01-01

    This book brings together in one volume fifteen Nobel Prize-winning discoveries that have had the greatest impact upon medical science and the practice of medicine during the 20th century and up to the present time. Its overall aim is to enlighten, entertain and stimulate. This is especially so for those who are involved in or contemplating a career in medical research. Anyone interested in the particulars of a specific award or Laureate can obtain detailed information on the topic by accessing the Nobel Foundation's website. In contrast, this book aims to provide a less formal and more personal view of the science and scientists involved, by having prominent academics write a chapter each about a Nobel Prize-winning discovery in their own areas of interest and expertise.

  7. IEEE Prize for Lucio Rossi

    2007-01-01

    Lucio Rossi receives his prize from John Spargo, Chairman of the IEEE Council on Superconductivity (left), and Martin Nisenoff, Chairman of the Council on Superconductivity’s Awards Committee (right). (Photo: IEEE Council on Superconductivity)With the magnets installed in the tunnel and work on the interconnections almost completed, Lucio Rossi has reaped the rewards of fifteen years of work. And yet, when the physicist from Milan arrived to take charge of the group responsible for the superconducting magnets in 2001, success seemed far from assured. Endowed with surprising levels of energy, Lucio Rossi, together with his team, ensured that production of these highly complex magnets got underway. Today, that achievement earns them the recognition not only of CERN but also of the international superconducting community. It is for this achievement that Lucio Rossi was awarded the prize by the IEEE’s (Institute of Electrical an...

  8. The 2009 Physics Nobel Prize

    José Maria Filardo Bassalo

    2010-09-01

    Full Text Available In this article we will talk about the Nobel Prize in Physics 2009, granted to the physicists north-americans: Charles Kuen Kao (born in China, for its discovery of the process of transmission of light in optical fibers; and Willard Sterling Boyle (born in Canada and George Elwood Smith, for the invention of an imaging semiconductor circuit – the CCD sensor.

  9. Higgs cosmology.

    Rajantie, Arttu

    2018-03-06

    The discovery of the Higgs boson in 2012 and other results from the Large Hadron Collider have confirmed the standard model of particle physics as the correct theory of elementary particles and their interactions up to energies of several TeV. Remarkably, the theory may even remain valid all the way to the Planck scale of quantum gravity, and therefore it provides a solid theoretical basis for describing the early Universe. Furthermore, the Higgs field itself has unique properties that may have allowed it to play a central role in the evolution of the Universe, from inflation to cosmological phase transitions and the origin of both baryonic and dark matter, and possibly to determine its ultimate fate through the electroweak vacuum instability. These connections between particle physics and cosmology have given rise to a new and growing field of Higgs cosmology, which promises to shed new light on some of the most puzzling questions about the Universe as new data from particle physics experiments and cosmological observations become available.This article is part of the Theo Murphy meeting issue 'Higgs cosmology'. © 2018 The Author(s).

  10. Cosmological principle

    Wesson, P.S.

    1979-01-01

    The Cosmological Principle states: the universe looks the same to all observers regardless of where they are located. To most astronomers today the Cosmological Principle means the universe looks the same to all observers because density of the galaxies is the same in all places. A new Cosmological Principle is proposed. It is called the Dimensional Cosmological Principle. It uses the properties of matter in the universe: density (rho), pressure (p), and mass (m) within some region of space of length (l). The laws of physics require incorporation of constants for gravity (G) and the speed of light (C). After combining the six parameters into dimensionless numbers, the best choices are: 8πGl 2 rho/c 2 , 8πGl 2 rho/c 4 , and 2 Gm/c 2 l (the Schwarzchild factor). The Dimensional Cosmological Principal came about because old ideas conflicted with the rapidly-growing body of observational evidence indicating that galaxies in the universe have a clumpy rather than uniform distribution

  11. Higgs cosmology

    Rajantie, Arttu

    2018-01-01

    The discovery of the Higgs boson in 2012 and other results from the Large Hadron Collider have confirmed the standard model of particle physics as the correct theory of elementary particles and their interactions up to energies of several TeV. Remarkably, the theory may even remain valid all the way to the Planck scale of quantum gravity, and therefore it provides a solid theoretical basis for describing the early Universe. Furthermore, the Higgs field itself has unique properties that may have allowed it to play a central role in the evolution of the Universe, from inflation to cosmological phase transitions and the origin of both baryonic and dark matter, and possibly to determine its ultimate fate through the electroweak vacuum instability. These connections between particle physics and cosmology have given rise to a new and growing field of Higgs cosmology, which promises to shed new light on some of the most puzzling questions about the Universe as new data from particle physics experiments and cosmological observations become available. This article is part of the Theo Murphy meeting issue `Higgs cosmology'.

  12. Deconstructing cosmology

    Sanders, Robert H

    2016-01-01

    The advent of sensitive high-resolution observations of the cosmic microwave background radiation and their successful interpretation in terms of the standard cosmological model has led to great confidence in this model's reality. The prevailing attitude is that we now understand the Universe and need only work out the details. In this book, Sanders traces the development and successes of Lambda-CDM, and argues that this triumphalism may be premature. The model's two major components, dark energy and dark matter, have the character of the pre-twentieth-century luminiferous aether. While there is astronomical evidence for these hypothetical fluids, their enigmatic properties call into question our assumptions of the universality of locally determined physical law. Sanders explains how modified Newtonian dynamics (MOND) is a significant challenge for cold dark matter. Overall, the message is hopeful: the field of cosmology has not become frozen, and there is much fundamental work ahead for tomorrow's cosmologis...

  13. Patents, Inducement Prizes, and Contestant Strategy

    Davis, Jerome; Davis, Lee N.

    2006-01-01

    Debate over the merits of patents versus inducement prizes has tended to ignore the signaling roles of patents, and totally ignores the impact of patent signaling on prize contests. This paper asks: How does patent signaling affect the strategic choices of firms considering entering prize contests......? First, we consider contests that do not allow patenting, then contests that do. If patenting is not allowed, we argue, patent-holders, both internal and external to the contest, can adversely impact prize contests by claiming prize winner violation of their patents, and suing for damages. The likelihood...... of such challenges being made can deter entry, particularly in contests requiring large sunk costs. Furthermore, the firm's decisionmaking process will discriminate against entering prize contests and favor R&D projects with patentable outcomes. Together, these problems may circumscribe any future wider role...

  14. Fractal cosmology

    Dickau, Jonathan J.

    2009-01-01

    The use of fractals and fractal-like forms to describe or model the universe has had a long and varied history, which begins long before the word fractal was actually coined. Since the introduction of mathematical rigor to the subject of fractals, by Mandelbrot and others, there have been numerous cosmological theories and analyses of astronomical observations which suggest that the universe exhibits fractality or is by nature fractal. In recent years, the term fractal cosmology has come into usage, as a description for those theories and methods of analysis whereby a fractal nature of the cosmos is shown.

  15. Full implementation of rank-dependent prizes

    Midjord, Rune

    2013-01-01

    A manager/mechanism designer must allocate a set of money prizes ($1,$2,…,$n) between n agents working in a team. The agents know the state, i.e., who contributed most, second most, etc. The agents’ preferences over prizes are state independent. We incorporate the possibility that the manager knows...... the state with a tiny probability and present a simple mechanism that uniquely awards prizes that respect the true state....

  16. The image of the Nobel Prize.

    Källstrand, Gustav

    2018-05-01

    This article traces the origins of the Nobel Prize as a ubiquitous symbol of excellence in science. The public image of the Nobel Prize was created and became established quickly, which can be explained by it being such a useful phenomenon for the co-production of other values and ideas such as national prestige. Through being an easily recognizable symbol for excellence, the Nobel Prize is an important factor for the public image of science. And the image of the Nobel Prize is co-produced with several other sets of values and images that range from the large and thematic to the local and specific.

  17. Cosmological inflation

    Enqvist, K

    2012-01-01

    The very basics of cosmological inflation are discussed. We derive the equations of motion for the inflaton field, introduce the slow-roll parameters, and present the computation of the inflationary perturbations and their connection to the temperature fluctuations of the cosmic microwave background.

  18. Mathematical cosmology

    Ellis, G F R

    1993-01-01

    Many topics were covered in the submitted papers, showing much life in this subject at present. They ranged from conventional calculations in specific cosmological models to provocatively speculative work. Space and time restrictions required selecting from them, for summarisation here; the book of Abstracts should be consulted for a full overview.

  19. Galileon cosmology

    Chow, Nathan; Khoury, Justin

    2009-01-01

    We study the cosmology of a galileon scalar-tensor theory, obtained by covariantizing the decoupling Lagrangian of the Dvali-Gabadadze-Poratti (DGP) model. Despite being local in 3+1 dimensions, the resulting cosmological evolution is remarkably similar to that of the full 4+1-dimensional DGP framework, both for the expansion history and the evolution of density perturbations. As in the DGP model, the covariant galileon theory yields two branches of solutions, depending on the sign of the galileon velocity. Perturbations are stable on one branch and ghostlike on the other. An interesting effect uncovered in our analysis is a cosmological version of the Vainshtein screening mechanism: at early times, the galileon dynamics are dominated by self-interaction terms, resulting in its energy density being suppressed compared to matter or radiation; once the matter density has redshifted sufficiently, the galileon becomes an important component of the energy density and contributes to dark energy. We estimate conservatively that the resulting expansion history is consistent with the observed late-time cosmology, provided that the scale of modification satisfies r c > or approx. 15 Gpc.

  20. BOS MOrth cases prize 2011.

    Patel, Jigar Vipinchandra

    2013-12-01

    This paper describes the orthodontic treatment of two cases awarded the prize by the British Orthodontic Society for best treated cases submitted for the Membership in Orthodontics. The first case reports on the treatment of a class III malocclusion with increased vertical lower anterior facial proportions and dentoalveolar compensation that was treated with orthodontic camouflage. The second case reports on the treatment of a class II division II malocclusion with reduced vertical lower anterior facial proportions and an overbite complete to the palate, which was treated with orthodontic camouflage.

  1. 2014 WSEAT X-Prize

    Bosiljevac, Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kramer, Sharlotte [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Laing, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    The 2014 WSEAT X-Prize is modeled as a double blind study to challenge the computational and material mechanics communities methodologies to develop better capabilities in modeling and experimentation to predict the failure in ductile metals. The challenge is presented as a distinct, yet relatively, simple geometry with all reported modeling predictions blind to each of the modeling teams. The experimental testing is validated by two independent test labs to confirm the experimentally observed behavior and results are unbiased and repeatable. The WSEAT X-Prize was issued to both external participants and internal participants as the Sandia Fracture Challenge 2 (SFC2) on May 30, 2014. A Challenge Supplemental Information Packet was sent to participants on August 13, 2014 to Prior years SFCs focused on the ability to predict failures under a quasi-static loading condition that focused on either a shear or tensile-dominated failure mode. This year’s challenge focuses on a geometry with a shear and/or tensile-dominated failure mode influenced by a moderate strain-rate ductile fracture in a metallic alloy.

  2. Interview with Abel Prize recipient Lennart Carleson

    Raussen, Martin; Skau, Christian

    2006-01-01

    The interview was conducted in Oslo on May 22nd 2006  prior to the Abel prize celebration and was later shown on Norwegian TV.......The interview was conducted in Oslo on May 22nd 2006  prior to the Abel prize celebration and was later shown on Norwegian TV....

  3. Broad Prize: Do the Successes Spread?

    Samuels, Christina A.

    2011-01-01

    When the Broad Prize for Urban Education was created in 2002, billionaire philanthropist Eli Broad said he hoped the awards, in addition to rewarding high-performing school districts, would foster healthy competition; boost the prestige of urban education, long viewed as dysfunctional; and showcase best practices. Over the 10 years the prize has…

  4. Synthesis and the Nobel Prize in Chemistry

    Seeman, Jeffrey I.

    2017-10-01

    The question often arises as to who may have deserved a Nobel Prize but was not awarded one. Rarely is this discussion extended to who should have received more than one Nobel Prize, but in the field of organic synthesis there are some compelling candidates.

  5. Interview with Abel Prize recipient Lennart Carleson

    Raussen, Martin; Skau, Christian

    2006-01-01

    The interview was conducted in Oslo on May 22nd 2006 prior to the Abel prize celebration and was later shown on Norwegian TV.......The interview was conducted in Oslo on May 22nd 2006 prior to the Abel prize celebration and was later shown on Norwegian TV....

  6. Interview with Abel Prize Recipient Lennart Carleson

    Raussen, Martin; Skau, Christian

    2007-01-01

    Lennart Carleson is the recipient of the 2006 Abel Prize of the Norwegian Academy of Science and Letters. On May 22, 2006, prior to the Abel Prize celebration i Oslo, Carleson was interviewed by Martin Raussen of Aalborg University and Christian Skau of the Norwegian University of Science...

  7. Slovak National Prize for Quality 2004

    Steflik, Marian

    2009-01-01

    Competition for the Slovak National Prize for Quality is a milestone in the history of the Mochovce NPP. The Mochovce NPP won the prize in 2004. The article describes in detail the preparatory efforts including not only technological issues but also various administrative challenges. The impacts of this achievement on the plant's subsequent development are also highlighted. (orig.)

  8. MIT professor wins major international math prize

    Allen, S

    2004-01-01

    Mathematicians Isadore Singer of MIT and Sir Michael Francis Atiyah of the University of Edinburgh will share an $875,000 award as winners of the second Abel Prize, which some hope will come to be seen as a Nobel Prize for math.

  9. Medieval Cosmology

    Grant, E.; Murdin, P.

    2000-11-01

    During the early Middle Ages (ca 500 to ca 1130) scholars with an interest in cosmology had little useful and dependable literature. They relied heavily on a partial Latin translation of PLATO's Timaeus by Chalcidius (4th century AD), and on a series of encyclopedic treatises associated with the names of Pliny the Elder (ca AD 23-79), Seneca (4 BC-AD 65), Macrobius (fl 5th century AD), Martianus ...

  10. Observational cosmology

    Partridge, R.B.

    1977-01-01

    Some sixty years after the development of relativistic cosmology by Einstein and his colleagues, observations are finally beginning to have an important impact on our views of the Universe. The available evidence seems to support one of the simplest cosmological models, the hot Big Bang model. The aim of this paper is to assess the observational support for certain assumptions underlying the hot Big Bang model. These are that the Universe is isobaric and homogeneous on a large scale; that it is expanding from an initial state of high density and temperature; and that the proper theory to describe the dynamics of the Universe is unmodified General Relativity. The properties of the cosmic microwave background radiation and recent observations of the abundance of light elements, in particular, support these assumptions. Also examined here are the data bearing on the related questions of the geometry and the future of the Universe (is it ever-expanding, or fated to recollapse). Finally, some difficulties and faults of the standard model are discussed, particularly various aspects of the 'initial condition' problem. It appears that the simplest Big Bang cosmological model calls for a highly specific set of initial conditions to produce the presently observed properties of the Universe. (Auth.)

  11. Smoot Group Cosmology

    the Universe About Cosmology Planck Satellite Launched Cosmology Videos Professor George Smoot's group conducts research on the early universe (cosmology) using the Cosmic Microwave Background radiation (CMB science goals regarding cosmology. George Smoot named Director of Korean Cosmology Institute The GRB

  12. Science Underlying 2008 Nobel Prizes

    Caldwell, Bernadette A.

    2009-01-01

    JCE offers a wealth of materials for teaching and learning chemistry that you can explore online. In the list below, Bernadette Caldwell of the Editorial Staff suggests additional resources that are available through JCE for teaching the science behind some of the 2008 Nobel Prizes . Discovering and Applying the Chemistry of GFP The Royal Swedish Academy of Sciences awarded the 2008 Nobel Prize in Chemistry for the discovery and development of the green fluorescent protein, GFP to three scientists: Osamu Shimomura, Martin Chalfie, and Roger Y. Tsien. These scientists led the field in discovering and introducing a fluorescing protein from jellyfish into cells and genes under study, which allows researchers to witness biochemistry in action. Now tags are available that emit light in different colors, revealing myriad biological processes and their interactions simultaneously. Identifying HPV and HIV, HIV's Replication Cycle, and HIV Virus-Host Interactions The Nobel Assembly at Karolinska Institutet awarded the 2008 Nobel Prize in Medicine or Physiology for their discovery of human immunodeficiency virus (HIV) to two scientists: Françoise Barré-Sinoussi and Luc Montagnier; and for his discovery of human papilloma viruses [HPV] causing cervical cancer to one scientist, Harald zur Hausen. Diseases caused by these infectious agents significantly affect global health. While isolating and studying the virus, researchers discovered HIV is an uncommon retrovirus that infects humans and relies on the host to make its viral DNA, infecting and killing the host's white blood cells, ultimately destroying the immune systems of infected humans. Related Resources at JCE Online The Journal has published articles relating to GFP specifically, and more generally to fluorescing compounds applied to biochemistry. The Journal has also published an article and a video on protease inhibition—a strategy to suppress HIV's biological processes. With the video clips, an accompanying guide

  13. Stellar students win fantastic prizes

    2008-05-01

    School students and teachers across Europe and around the world are discovering today who has won fantastic prizes in "Catch a Star", the international astronomical competition run by ESO and the European Association for Astronomy Education (EAAE). CAS2008 artwork ESO PR Photo 14/08 One of the winning artworks "We were extremely impressed by the high quality of the entries, and the number of participants was even higher than last year. We wish to congratulate everybody who took part," said Douglas Pierce-Price, Education Officer at ESO. "'Catch a Star' clearly shows astronomy's power to inspire and excite students of all ages," added Fernand Wagner, President of the EAAE. The top prize, of a week-long trip to Chile to visit the ESO Very Large Telescope (VLT) on Paranal, was won by students Roeland Heerema, Liesbeth Schenkels, and Gerben Van Ranst from the Instituut Spijker in Hoogstraten, Belgium, together with their teacher Ann Verstralen. With their "story of aged binary stars... Live and Let Die", they take us on a vivid tour of the amazing zoo of binary stars, and the life and death of stars like our Sun. The students show how state-of-the-art telescopes, particularly those at ESO's sites of La Silla and Paranal, help us understand these stars. They take as an illustrative example the binary star system V390 Velorum. In the last phases of its life, V390 Velorum will shed its outer shell of gas and dust, turning from a celestial chrysalis into a beautiful cosmic butterfly. The students also involved other pupils from their school, showing them how to test their eyesight by observing the binary star system of Alcor and Mizar. But perhaps the most important discovery they made is that, as they write in their report, "Astronomy lives! Discoveries are being made each day and there is still very much to be found and learned by astronomers!" The team will travel to Chile and visit the ESO VLT - the world's most advanced optical/infrared telescope. At Paranal, they

  14. String Gas Cosmology

    Brandenberger, Robert H.

    2008-01-01

    String gas cosmology is a string theory-based approach to early universe cosmology which is based on making use of robust features of string theory such as the existence of new states and new symmetries. A first goal of string gas cosmology is to understand how string theory can effect the earliest moments of cosmology before the effective field theory approach which underlies standard and inflationary cosmology becomes valid. String gas cosmology may also provide an alternative to the curren...

  15. Magnetohydrodynamic cosmologies

    Portugal, R.; Soares, I.D.

    1991-01-01

    We analyse a class of cosmological models in magnetohydrodynamic regime extending and completing the results of a previous paper. The material content of the models is a perfect fluid plus electromagnetic fields. The fluid is neutral in average but admits an electrical current which satisfies Ohm's law. All models fulfil the physical requirements of near equilibrium thermodynamics and can be favourably used as a more realistic description of the interior of a collapsing star in a magnetohydrodynamic regime with or without a magnetic field. (author)

  16. Astrophysical cosmology

    Bardeen, J. M.

    The last several years have seen a tremendous ferment of activity in astrophysical cosmology. Much of the theoretical impetus has come from particle physics theories of the early universe and candidates for dark matter, but what promise to be even more significant are improved direct observations of high z galaxies and intergalactic matter, deeper and more comprehensive redshift surveys, and the increasing power of computer simulations of the dynamical evolution of large scale structure. Upper limits on the anisotropy of the microwave background radiation are gradually getting tighter and constraining more severely theoretical scenarios for the evolution of the universe.

  17. Astrophysical cosmology

    Bardeen, J.M.

    1986-01-01

    The last several years have seen a tremendous ferment of activity in astrophysical cosmology. Much of the theoretical impetus has come from particle physics theories of the early universe and candidates for dark matter, but what promise to be even more significant are improved direct observations of high z galaxies and intergalactic matter, deeper and more comprehensive redshift surveys, and the increasing power of computer simulations of the dynamical evolution of large scale structure. Upper limits on the anisotropy of the microwave background radiation are gradually getting tighter and constraining more severely theoretical scenarios for the evolution of the universe. 47 refs

  18. Chemical cosmology

    Boeyens, Jan CA

    2010-01-01

    The composition of the most remote objects brought into view by the Hubble telescope can no longer be reconciled with the nucleogenesis of standard cosmology and the alternative explanation, in terms of the LAMBDA-Cold-Dark-Matter model, has no recognizable chemical basis. A more rational scheme, based on the chemistry and periodicity of atomic matter, opens up an exciting new interpretation of the cosmos in terms of projective geometry and general relativity. The response of atomic structure to environmental pressure predicts non-Doppler cosmical redshifts and equilibrium nucleogenesis by alp

  19. Quantum Cosmology

    Page, Don N.

    2006-01-01

    A complete model of the universe needs at least three parts: (1) a complete set of physical variables and dynamical laws for them, (2) the correct solution of the dynamical laws, and (3) the connection with conscious experience. In quantum cosmology, item (2) is the quantum state of the cosmos. Hartle and Hawking have made the `no-boundary' proposal, that the wavefunction of the universe is given by a path integral over all compact Euclidean 4-dimensional geometries and matter fields that hav...

  20. Religion, theology and cosmology

    John T. Fitzgerald

    2013-10-01

    Full Text Available Cosmology is one of the predominant research areas of the contemporary world. Advances in modern cosmology have prompted renewed interest in the intersections between religion, theology and cosmology. This article, which is intended as a brief introduction to the series of studies on theological cosmology in this journal, identifies three general areas of theological interest stemming from the modern scientific study of cosmology: contemporary theology and ethics; cosmology and world religions; and ancient cosmologies. These intersections raise important questions about the relationship of religion and cosmology, which has recently been addressed by William Scott Green and is the focus of the final portion of the article.

  1. Nuclear Fusion prize laudation Nuclear Fusion prize laudation

    Burkart, W.

    2011-01-01

    Clean energy in abundance will be of critical importance to the pursuit of world peace and development. As part of the IAEA's activities to facilitate the dissemination of fusion related science and technology, the journal Nuclear Fusion is intended to contribute to the realization of such energy from fusion. In 2010, we celebrated the 50th anniversary of the IAEA journal. The excellence of research published in the journal is attested to by its high citation index. The IAEA recognizes excellence by means of an annual prize awarded to the authors of papers judged to have made the greatest impact. On the occasion of the 2010 IAEA Fusion Energy Conference in Daejeon, Republic of Korea at the welcome dinner hosted by the city of Daejeon, we celebrated the achievements of the 2009 and 2010 Nuclear Fusion prize winners. Steve Sabbagh, from the Department of Applied Physics and Applied Mathematics, Columbia University, New York is the winner of the 2009 award for his paper: 'Resistive wall stabilized operation in rotating high beta NSTX plasmas' [1]. This is a landmark paper which reports record parameters of beta in a large spherical torus plasma and presents a thorough investigation of the physics of resistive wall mode (RWM) instability. The paper makes a significant contribution to the critical topic of RWM stabilization. John Rice, from the Plasma Science and Fusion Center, MIT, Cambridge is the winner of the 2010 award for his paper: 'Inter-machine comparison of intrinsic toroidal rotation in tokamaks' [2]. The 2010 award is for a seminal paper that analyzes results across a range of machines in order to develop a universal scaling that can be used to predict intrinsic rotation. This paper has already triggered a wealth of experimental and theoretical work. I congratulate both authors and their colleagues on these exceptional papers. W. Burkart Deputy Director General Department of Nuclear Sciences and Applications International Atomic Energy Agency, Vienna

  2. Fermionic cosmologies

    Chimento, L P; Forte, M; Devecchi, F P; Kremer, G M; Ribas, M O; Samojeden, L L

    2011-01-01

    In this work we review if fermionic sources could be responsible for accelerated periods during the evolution of a FRW universe. In a first attempt, besides the fermionic source, a matter constituent would answer for the decelerated periods. The coupled differential equations that emerge from the field equations are integrated numerically. The self-interaction potential of the fermionic field is considered as a function of the scalar and pseudo-scalar invariants. It is shown that the fermionic field could behave like an inflaton field in the early universe, giving place to a transition to a matter dominated (decelerated) period. In a second formulation we turn our attention to analytical results, specifically using the idea of form-invariance transformations. These transformations can be used for obtaining accelerated cosmologies starting with conventional cosmological models. Here we reconsider the scalar field case and extend the discussion to fermionic fields. Finally we investigate the role of a Dirac field in a Brans-Dicke (BD) context. The results show that this source, in combination with the BD scalar, promote a final eternal accelerated era, after a matter dominated period.

  3. 2011 Nobel Prize in Physics Supernovae explosions and the Accelerating Universe

    Ziegler, B.

    2011-01-01

    This year, 2011, the nobel prize in physics is given to three astronomers (Perlmutter, Schmidt, Riess) 'for the discovery of the accelerating expansion of the Universe through observations of distant supernovae'. In my seminar talk, I will thus present first some basic astrophysics on supernovae star explosions and the cosmological principle of an expanding Universe. Next, I will summarize the observations and measurements of the two teams behind the noble prize winners and show how the simplest explanations of the unexpected findings lead to the concept of an accelerating Universe. I will end my talk with an outlook on ongoing and future efforts to measure the equation-of-state of the Dark Energy postulated to explain the observations. (author)

  4. Preimplantation genetic diagnosis for a Chinese family with autosomal recessive Meckel-Gruber syndrome type 3 (MKS3.

    Yanping Lu

    Full Text Available Meckel-Gruber syndrome type 3 is an autosomal recessive genetic defect caused by mutations in TMEM67 gene. In our previous study, we have identified a homozygous TMEM67 mutation in a Chinese family exhibiting clinical characteristics of MKS3, which provided a ground for further PGD procedure. Here we report the development and the first clinical application of the PGD for this MKS3 family. Molecular analysis protocol for clinical PGD procedure was established using 50 single cells in pre-clinical set-up. After whole genomic amplification by multiple displacement amplification with the DNA from single cells, three techniques were applied simultaneously to increase the accuracy and reliability of genetic diagnosis in single blastomere, including real-time PCR with Taq Man-MGB probe, haplotype analysis with polymorphic STR markers and Sanger sequencing. In the clinical PGD cycle, nine embryos at cleavage-stage were biopsied and subjected to genetic diagnosis. Two embryos diagnosed as free of TMEM67 mutation were transferred and one achieving normal pregnancy. Non-invasive prenatal assessment of trisomy 13, 18 and 21 by multiplex DNA sequencing at 18 weeks' gestation excluded the aneuploidy of the analyzed chromosomes. A healthy boy was delivered by cesarean section at 39 weeks' gestation. DNA sequencing from his cord blood confirmed the result of genetic analysis in the PGD cycle. The protocol developed in this study was proved to be rapid and safe for the detection of monogenic mutations in clinical PGD cycle.

  5. ACFA and IPAC announce accelerator prizes

    CERN Bulletin

    2010-01-01

    Steve Myers, CERN's Director for Accelerators and Technology. The Asian Committee for Future Accelerators (ACFA) has joined forces with the first International Particle Accelerator Conference, IPAC’10, to award prizes for outstanding work in the field of accelerators. The conference replaces the regional conferences of the Americas, Europe and Asia and will be hosted by the three regions on a rotational basis (see CERN Courier). The ACFA/IPAC’10 Prizes Selection Committee, chaired by Won Namkung of Pohang Accelerator Laboratory, decided on the prizes and the names of the winners at a meeting on 20 January. The awards will be made during IPAC’10, which will be held in Kyoto on 23-28 May. Jie Wei. (Courtesy Tsinghua University.) Steve Myers, Director for Accelerators and Technology at CERN, receives an Achievement Prize for Outstanding Work in the Accelerator Field with no Age Limit “for his numerous outstanding contributions to the design, construction, commissio...

  6. Strong-force theorists scoop Noble Prize

    Durrani, Matin

    2004-01-01

    Three US theorists have shared the 2004 Nobel Prize in Physics "for the discovery of asymptotic freedom in the theory of the strong interaction". Their theoretical work explains why quarks behave almost as free particles at high energies (½ page)

  7. Nobel Prize for work on broken symmetries

    2008-01-01

    The 2008 Nobel Prize for Physics goes to three physicists who have worked on broken symmetries in particle physics. The announcement of the 2008 Nobel Prize for physics was transmitted to the Globe of Science and Innovation via webcast on the occasion of the preview of the Nobel Accelerator exhibition.On 7 October it was announced that the Royal Swedish Academy of Sciences had awarded the 2008 Nobel Prize for physics to three particle physicists for their fundamental work on the mechanisms of broken symmetries. Half the prize was awarded to Yoichiro Nambu of Fermilab for "the discovery of the mechanism of spontaneous broken symmetry in subatomic physics". The other half is shared by Makato Kobayashi of Japan’s KEK Institute and Toshihide Maskawa of the Yukawa Institute at the University of Kyoto "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in Nature". At th...

  8. The 2016 Nobel Prize: Chemistry and Physics

    José Maria Filardo Bassalo

    2017-08-01

    Full Text Available In this article, we will deal with the 2016 Nobel Prizes: Chemistry and Physics, since they are related to the same theme: nanostructures / molecular machines (conception, fabrication and topological theoretical explanation.

  9. A Nobel Prize in Czechoslovakia; Yaroslav Geyrovskiy

    Brabernets, Irzhi

    1960-01-01

    The notification of the awarding of a Nobel Prize to Yaroslav Geyrovskiy in the field of chemistry in l959 came to the scientist while he was at work at the Polarographic Institute of the Czechoslovak...

  10. Interview with Abel Prize Recipient Srinivasa Varadhan

    Raussen, Martin; Skau, Christian

    2008-01-01

    His Majesty King Harald presented the Abel Prize for 2007 to Srinivasa Varadhan at an award ceremony in the University Aula in Oslo on the 22nd May, 2007. The interview was conducted the day before the ceremony.......His Majesty King Harald presented the Abel Prize for 2007 to Srinivasa Varadhan at an award ceremony in the University Aula in Oslo on the 22nd May, 2007. The interview was conducted the day before the ceremony....

  11. Dannie Heineman Prize for CERN theorist

    2003-01-01

    CERN's Gabriele Veneziano, is the recipient of the Dannie Heineman Prize for Mathematical Physics 2004, which he receives "for his pioneering discoveries in dual resonance models which, partly through his own efforts, have developed into string theory and a basis for the quantum theory of gravity". The prize was established in 1959 by the Heineman Foundation for Research, Educational, Charitable, and Scientific Purposes, and is administered jointly by the American Physical Society and the American Institute of Physics.

  12. [Surgeons and Neurosurgeons as Nobel Prize Winners].

    Chrastina, Jan; Jančálek, Radim; Hrabovský, Dušan; Novák, Zdeněk

    Since 1901 Nobel Prize is awarded for exceptional achievements in physics, chemistry, literature, peace, economy (since 1968) and medicine or physiology. The first aim of the paper is to provide an overview of surgeons - winners of Nobel Prize for medicine or physiology. Although the prominent neurosurgeons were frequently nominated as Nobel Prize candidates, surprisingly no neurosurgeon received this prestigious award so far despite that the results of their research transgressed the relatively narrow limits of neurosurgical speciality.The most prominent leaders in the field of neurosurgery, such as Victor Horsley, Otfrid Foerster, Walter Dandy and Harvey Cushing are discussed from the point of their nominations. The overview of the activity of the Portuguese neurologists and Nobel Prize Winter in 1949 Egas Moniz (occasionally erroneously reported as neurosurgeon) is also provided. Although his work on brain angiography has fundamentally changed the diagnostic possibilities in neurology and neurosurgery, he was eventually awarded Nobel Prize for the introduction of the currently outdated frontal lobotomy.The fact that none of the above mentioned prominent neurosurgeons has not been recognised by Nobel Prize, may be attributed to the fact that their extensive work cannot be captured in a short summary pinpointing its groundbreaking character.

  13. Scalar-tensor cosmology with cosmological constant

    Maslanka, K.

    1983-01-01

    The equations of scalar-tensor theory of gravitation with cosmological constant in the case of homogeneous and isotropic cosmological model can be reduced to dynamical system of three differential equations with unknown functions H=R/R, THETA=phi/phi, S=e/phi. When new variables are introduced the system becomes more symmetrical and cosmological solutions R(t), phi(t), e(t) are found. It is shown that when cosmological constant is introduced large class of solutions which depend also on Dicke-Brans parameter can be obtained. Investigations of these solutions give general limits for cosmological constant and mean density of matter in plane model. (author)

  14. Quantum cosmology

    Hawking, S.W.

    1984-01-01

    The subject of these lectures is quantum effects in cosmology. The author deals first with situations in which the gravitational field can be treated as a classical, unquantized background on which the quantum matter fields propagate. This is the case with inflation at the GUT era. Nevertheless the curvature of spacetime can have important effects on the behaviour of the quantum fields and on the development of long-range correlations. He then turns to the question of the quantization of the gravitational field itself. The plan of these lectures is as follows: Euclidean approach to quantum field theory in flat space; the extension of techniques to quantum fields on a curved background with the four-sphere, the Euclidean version of De Sitter space as a particular example; the GUT era; quantization of the gravitational field by Euclidean path integrals; mini superspace model. (Auth.)

  15. Network cosmology.

    Krioukov, Dmitri; Kitsak, Maksim; Sinkovits, Robert S; Rideout, David; Meyer, David; Boguñá, Marián

    2012-01-01

    Prediction and control of the dynamics of complex networks is a central problem in network science. Structural and dynamical similarities of different real networks suggest that some universal laws might accurately describe the dynamics of these networks, albeit the nature and common origin of such laws remain elusive. Here we show that the causal network representing the large-scale structure of spacetime in our accelerating universe is a power-law graph with strong clustering, similar to many complex networks such as the Internet, social, or biological networks. We prove that this structural similarity is a consequence of the asymptotic equivalence between the large-scale growth dynamics of complex networks and causal networks. This equivalence suggests that unexpectedly similar laws govern the dynamics of complex networks and spacetime in the universe, with implications to network science and cosmology.

  16. An introduction to cosmology

    Narlikar, Jayant Vishnu

    2002-01-01

    The third edition of this successful textbook is fully updated and includes important recent developments in cosmology. It begins with an introduction to cosmology and general relativity, and goes on to cover the mathematical models of standard cosmology. The physical aspects of cosmology, including primordial nucleosynthesis, the astroparticle physics of inflation, and the current ideas on structure formation are discussed. Alternative models of cosmology are reviewed, including the model of Quasi-Steady State Cosmology, which has recently been proposed as an alternative to Big Bang Cosmology.

  17. Nobel prize winners from Siemens company

    Anon

    2007-01-01

    This paper deals with the history of discoveries and scientists which worked in the Siemens company. First Nobel prize winners from Siemens company was Gustav Ludwig Hertz from Hamburg. In his doctoral dissertation he deals with the study of collisions of electrons with molecules of gases. In the physics this experiment is known as 'Franc and Hertz experiment', which confirmed state of energy in Bohr theory and in 1925 he obtained Nobel prize. In 1945, as a director of the Department of physics in the research laboratories of Siemens, he constructed cyclotron kernel - magnet with mass of 80 tonnes. The second Nobel prize winner was Dennis Gabor worked in the Laboratory for measurement and medicinal technology in Siemensstadt (Berlin). When he tried to increase the resolution of electron microscopy he discovered the holography (method of 3-dimensional imaging). In 1971 he obtained the Nobel prize. The third scientist - Ernst Ruska discovered electron microscope. At Siemens, he was involved in developing the first commercially-produced electron microscope in 1939. In 1986, Ernst Ruska was awarded half of the Nobel Prize in Physics for his many achievements in electron optics.

  18. Dimensional cosmological principles

    Chi, L.K.

    1985-01-01

    The dimensional cosmological principles proposed by Wesson require that the density, pressure, and mass of cosmological models be functions of the dimensionless variables which are themselves combinations of the gravitational constant, the speed of light, and the spacetime coordinates. The space coordinate is not the comoving coordinate. In this paper, the dimensional cosmological principle and the dimensional perfect cosmological principle are reformulated by using the comoving coordinate. The dimensional perfect cosmological principle is further modified to allow the possibility that mass creation may occur. Self-similar spacetimes are found to be models obeying the new dimensional cosmological principle

  19. Cosmology and particle physics

    Turner, M.S.

    1985-01-01

    The author reviews the standard cosmology, focusing on primordial nucleosynthesis, and discusses how the standard cosmology has been used to place constraints on the properties of various particles. Baryogenesis is examined in which the B, C, CP violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and the present baryon-to-baryon ratio. Monoposes, cosmology and astrophysics are reviewed. The author also discusses supersymmetry/supergravity and cosmology, superstrings and cosmology in extra dimensions, and axions, astrophics, and cosmology

  20. ALICE physicists receive 2014 Lise Meitner Prize

    Katarina Anthony

    2014-01-01

    On Wednesday, 3 September, four ALICE physicists were presented with the European Physical Society's 2014 Lise Meitner Prize for their outstanding contributions to nuclear physics (see here).   ALICE collaboration members Johanna Stachel (Heidelberg University, Germany), Peter Braun-Munzinger (GSI, Germany), Paolo Giubellino (INFN Turin, Italy, and CERN) and Jürgen Schukraft (CERN) were presented with their awards at a private ceremony held in the Globe of Science and Innovation. In addition to members of the ALICE collaboration, the ceremony was attended by members of the CERN Management including the Director-General, Rolf Heuer, as well as the EPS Nuclear Physics Board Chair, Douglas MacGregor, and the EPS Lise Meitner Prize Committee Chair, Victor Zamfir. For more information, please see "EPS honours CERN's heavy-ion researchers".  From left to right: Douglas MacGregor (EPS); Prize recipients Jürgen Schukraft,&a...

  1. Row bubbles up over particle prize

    Chalmers, Matthew

    2009-01-01

    "The European Physical Society (EPS) has defended its handling of the 2009 prize for high-energy and particle physics despite complaints that the awarding committee overlooked a vital scientific contribution to the prize-winning work. The biennial award, worth SwFr 5000, was given to collaborators on the Gargamelle bubble-chamber experiment at Cern for their descovery in 1973 of the "weak neutral current" - one of the ways in which the weak nuclear force is mediated between fundamental particles" (0.75 page)

  2. Two Nobel Prize winners in two days

    2006-01-01

    Living legend of physics, Professor Chen Ning Yang, delivered his CERN Colloquium in the Main Auditorium on 12th October (see photo). His numerous contributions to physics include the famous Yang-Mills theory, which underlies the Standard Model of particle physics, and the prediction of parity violation in weak interactions, for which he shared the Nobel prize with T. D. Lee in 1957. The day before, another Nobel laureate, Norman Ramsey, gave a TH Exceptional Seminar in the same auditorium. Ramsey shared the Nobel Prize with Hans G. Dehmelt and Wolfgang Paul in 1989 for developments in atomic precision spectroscopy.

  3. Particle theory and cosmology

    Gaisser, T.K.; Shafi, Q.; Barr, S.M.; Seckel, D.; Rusjan, E.; Fletcher, R.S.

    1991-01-01

    This report discusses research of professor at Bartol research institute in the following general areas: particle phenomenology and non-accelerator physics; particle physics and cosmology; theories with higher symmetry; and particle astrophysics and cosmology

  4. Friedman's cosmological views

    Heller, M.

    1985-01-01

    Two Friedman's cosmological papers (1922, 1924) and his own interpretation of the obtained results are briefly reviewed. Discussion follows of Friedman's role in the early development of relativistic cosmology. 18 refs. (author)

  5. An introduction to cosmology

    Kunze, Kerstin E.

    2016-12-20

    Cosmology is becoming an important tool to test particle physics models. We provide an overview of the standard model of cosmology with an emphasis on the observations relevant for testing fundamental physics.

  6. Introduction to cosmology

    Roos, Matts

    2015-01-01

    The Fourth Edition of Introduction to Cosmology provides a concise, authoritative study of cosmology at an introductory level. Starting from elementary principles and the early history of cosmology, the text carefully guides the student on to curved spacetimes, special and general relativity, gravitational lensing, the thermal history of the Universe, and cosmological models, including extended gravity models, black holes and Hawking's recent conjectures on the not-so-black holes.

  7. Particle physics and cosmology

    Turner, M.S.; Schramm, D.N.

    1985-01-01

    During the past year, the research of the members of our group has spanned virtually all the topics at the interface of cosmology and particle physics: inflationary Universe scenarios, astrophysical and cosmological constraints on particle properties, ultra-high energy cosmic ray physics, quantum field theory in curved space-time, cosmology with extra dimensions, superstring cosmology, neutrino astronomy with large, underground detectors, and the formation of structure in the Universe

  8. Stephen Hawking bags big new 3m physics prize

    Johnston, Hamish

    2013-01-01

    A massive 3m in prize money has gone to the British cosmologist Stephen Hawking for his work on black holes, quantum gravity and the early universe. The award is one of two "special fundamental physics prizes" from the Fundamental Physics Prize Foundation, which was set up earlier this year by the Russian physicist-turned-entrepreneur Yuri Milner.

  9. NREL Solar Cell Wins Federal Technology Transfer Prize | News | NREL

    Solar Cell Wins Federal Technology Transfer Prize News Release: NREL Solar Cell Wins Federal Technology Transfer Prize May 7, 2009 A new class of ultra-light, high-efficiency solar cells developed by the U.S. Department of Energy's National Renewable Energy Laboratory has been awarded a national prize

  10. Phantom cosmologies and fermions

    Chimento, Luis P; Forte, Monica; Devecchi, Fernando P; Kremer, Gilberto M

    2008-01-01

    Form invariance transformations can be used for constructing phantom cosmologies starting with conventional cosmological models. In this work we reconsider the scalar field case and extend the discussion to fermionic fields, where the 'phantomization' process exhibits a new class of possible accelerated regimes. As an application we analyze the cosmological constant group for a fermionic seed fluid

  11. Particle physics and cosmology

    Schramm, D.N.; Turner, M.S.

    1982-06-01

    work is described in these areas: cosmological baryon production; cosmological production of free quarks and other exotic particle species; the quark-hadron transition in the early universe; astrophysical and cosmological constraints on particle properties; massive neutrinos; phase transitions in the early universe; and astrophysical implications of an axion-like particle

  12. Cosmological constant problem

    Weinberg, S.

    1989-01-01

    Cosmological constant problem is discussed. History of the problem is briefly considered. Five different approaches to solution of the problem are described: supersymmetry, supergravity, superstring; anthropic approach; mechamism of lagrangian alignment; modification of gravitation theory and quantum cosmology. It is noted that approach, based on quantum cosmology is the most promising one

  13. Smoot Cosmology Group

    . ______________________________________________________________________________________ Nobelist George Smoot to Direct Korean Cosmology Institute Nobel Laureate George Smoot has been appointed director of a new cosmology institute in South Korea that will work closely with the year-old Berkeley the Early Universe (IEU) at EWHA Womans University in Seoul, Korea will provide cosmology education

  14. Everyone's guide to cosmology

    Davies, P.

    1991-01-01

    The main concepts of cosmology are discussed, and some of the misconceptions are clarified. The features of big bang cosmology are examined, and it is noted that the existence of the cosmic background radiation provides welcome confirmation of the big bang theory. Calculations of relative abundances of the elements conform with observations, further strengthening the confidence in the basic ideas of big bang cosmology

  15. Introduction to cosmology

    CERN. Geneva. Audiovisual Unit

    2001-01-01

    Cosmology and particle physics have enjoyed a useful relationship over the entire histories of both subjects. Today, ideas and techniques in cosmology are frequently used to elucidate and constrain theories of elementary particles. These lectures give an elementary overview of the essential elements of cosmology, which is necessary to understand this relationship.

  16. Introduction to cosmology

    CERN. Geneva

    1999-01-01

    Cosmology and particle physics have enjoyed a useful relationship over the entire histories of both subjects. Today, ideas and techniques in cosmology are frequently used to elucidate and constrain theories of elementary particles. These lectures give an elementary overview of the essential elements of cosmology, which is necessary to understand this relationship.

  17. A savour of Cosmology

    Langer, M.

    2007-01-01

    This is a very concise introductory lecture to Cosmology. We start by reviewing the basics of homogeneous and isotropic cosmology. We then spend some time on the description of the Cosmic Microwave Background. Finally, a small section is devoted to the discussion of the cosmological constant and of some of the related problems

  18. The 2009 Nobel Prize in Physics

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 8. The 2009 Nobel Prize in Physics - Honoring Achievements in Optics that have Changed Modern Life. Vasant Natarajan. General Article Volume 15 Issue 8 August 2010 pp 723-732 ...

  19. Chemical lasers in competition for Lenin Prize

    Khariton, Yu.

    1984-03-12

    A brief essay is given to support the entrance of the cycle fundamental investigations of chemical lasers in chain reactions presented by the Physics Institute and Institute of Chemical Physics, USSR Academy of Sciences, for the competition for the 1984 Lenin Prize.

  20. ALICE physicists receive 2014 Lise Meitner Prize

    Jeanneret, Guillaume

    2014-01-01

    September 3rd, 2014: ALICE collaboration members Johanna Stachel (Heidelberg University, Germany), Peter Braun-Munzinger (GSI, Germany), Paolo Giubellino (INFN Turin, Italy, and CERN) and Jürgen Schukraft (CERN) were presented the 2014 Lise Meitner Prize at a private ceremony held in the Globe of Science and Innovation.

  1. Venture Leaders Prize for innovative technology projects

    2006-01-01

    In co-operation with the GEBERT RÜF FOUNDATION and the Ernest & Young Entrepreneur of the Year Award, venturelab will be presenting the Venture Leaders Prize. The Venture Leaders Prize, which is the new guise of the NETS (New Entrepreneurs in Technology and Science) Prize, will give twenty research entrepreneurs with projects to develop innovative technologies the opportunity to win the chance of participating in a programme to assist them in starting up their companies. The winners will go to spend 10 days in the Boston area (United States) where they will take part in a development programme for their project, which will include an entrepreneurship course, opportunities to meet start-up companies and financing experts, etc. This prize has already spawned many companies such as id Quantique, Selexis or ABMI which have contributed to the economic development of regions, particularly in French-speaking Switzerland. The competition is open to students and scientists from all fields, who would like to s...

  2. Nobel Prize in Physiology or Medicine 1999

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. Nobel Prize in Physiology or Medicine 1999. Utpal Tatu. Research News Volume 5 Issue 5 May 2000 pp 91-95. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/005/05/0091-0095 ...

  3. L Prize Drives Technology Innovation, Energy Savings

    None

    2014-04-30

    Fact sheet that provides an overview of DOE's L Prize competition, which challenges industry to develop high-quality, high-efficiency SSL products to replace 60W incandescent and PAR38 halogen light bulbs, and highlights the competition's first 60W winner from Philips Lighting North America.

  4. The Philosophy of Cosmology

    Chamcham, Khalil; Silk, Joseph; Barrow, John D.; Saunders, Simon

    2017-04-01

    Part I. Issues in the Philosophy of Cosmology: 1. Cosmology, cosmologia and the testing of cosmological theories George F. R. Ellis; 2. Black holes, cosmology and the passage of time: three problems at the limits of science Bernard Carr; 3. Moving boundaries? - comments on the relationship between philosophy and cosmology Claus Beisbart; 4. On the question why there exists something rather than nothing Roderich Tumulka; Part II. Structures in the Universe and the Structure of Modern Cosmology: 5. Some generalities about generality John D. Barrow; 6. Emergent structures of effective field theories Jean-Philippe Uzan; 7. Cosmological structure formation Joel R. Primack; 8. Formation of galaxies Joseph Silk; Part III. Foundations of Cosmology: Gravity and the Quantum: 9. The observer strikes back James Hartle and Thomas Hertog; 10. Testing inflation Chris Smeenk; 11. Why Boltzmann brains do not fluctuate into existence from the de Sitter vacuum Kimberly K. Boddy, Sean M. Carroll and Jason Pollack; 12. Holographic inflation revised Tom Banks; 13. Progress and gravity: overcoming divisions between general relativity and particle physics and between physics and HPS J. Brian Pitts; Part IV. Quantum Foundations and Quantum Gravity: 14. Is time's arrow perspectival? Carlo Rovelli; 15. Relational quantum cosmology Francesca Vidotto; 16. Cosmological ontology and epistemology Don N. Page; 17. Quantum origin of cosmological structure and dynamical reduction theories Daniel Sudarsky; 18. Towards a novel approach to semi-classical gravity Ward Struyve; Part V. Methodological and Philosophical Issues: 19. Limits of time in cosmology Svend E. Rugh and Henrik Zinkernagel; 20. Self-locating priors and cosmological measures Cian Dorr and Frank Arntzenius; 21. On probability and cosmology: inference beyond data? Martin Sahlén; 22. Testing the multiverse: Bayes, fine-tuning and typicality Luke A. Barnes; 23. A new perspective on Einstein's philosophy of cosmology Cormac O

  5. Philosophical Roots of Cosmology

    Ivanovic, M.

    2008-10-01

    We shall consider the philosophical roots of cosmology in the earlier Greek philosophy. Our goal is to answer the question: Are earlier Greek theories of pure philosophical-mythological character, as often philosophers cited it, or they have scientific character. On the bases of methodological criteria, we shall contend that the latter is the case. In order to answer the question about contemporary situation of the relation philosophy-cosmology, we shall consider the next question: Is contemporary cosmology completely independent of philosophical conjectures? The answer demands consideration of methodological character about scientific status of contemporary cosmology. We also consider some aspects of the relation contemporary philosophy-cosmology.

  6. First Calderón Prize

    Rundell, William; Somersalo, Erkki

    2008-07-01

    The Inverse Problems International Association (IPIA) awarded the first Calderón Prize to Matti Lassas for his outstanding contributions to the field of inverse problems, especially in geometric inverse problems. The Calderón Prize is given to a researcher under the age of 40 who has made distinguished contributions to the field of inverse problems broadly defined. The first Calderón Prize Committee consisted of Professors Adrian Nachman, Lassi Päivärinta, William Rundell (chair), and Michael Vogelius. William Rundell For the Calderón Prize Committee Prize ceremony The ceremony awarding the Calderón Prize. Matti Lassas is on the left. He and William Rundell are on the right. Photos by P Stefanov. Brief Biography of Matti Lassas Matti Lassas was born in 1969 in Helsinki, Finland, and studied at the University of Helsinki. He finished his Master's studies in 1992 in three years and earned his PhD in 1996. His PhD thesis, written under the supervision of Professor Erkki Somersalo was entitled `Non-selfadjoint inverse spectral problems and their applications to random bodies'. Already in his thesis, Matti demonstrated a remarkable command of different fields of mathematics, bringing together the spectral theory of operators, geometry of Riemannian surfaces, Maxwell's equations and stochastic analysis. He has continued to develop all of these branches in the framework of inverse problems, the most remarkable results perhaps being in the field of differential geometry and inverse problems. Matti has always been a very generous researcher, sharing his ideas with his numerous collaborators. He has authored over sixty scientific articles, among which a monograph on inverse boundary spectral problems with Alexander Kachalov and Yaroslav Kurylev and over forty articles in peer reviewed journals of the highest standards. To get an idea of the wide range of Matti's interests, it is enough to say that he also has three US patents on medical imaging applications. Matti is

  7. Two Nobel Prizes connected to CERN

    2003-01-01

    The 2003 Nobel Prizes in Physics and in Physiology or Medicine, announced last week, both have connections with particle physics and CERN. Alexei Abrikosov, Vitaly Ginzburg and Anthony Leggett have received the prize in physics for their "pioneering contributions to the theory of superconductors and superfluids". The most important superconducting materials technically have proved to be those known as type II superconductors, which allow superconductivity and magnetism to exist at the same time and remain superconductive in high magnetic fields. The coils for the superconducting magnets in CERN's Large Hadron Collider are made from niobium-titanium alloy - a type II superconductor. The LHC will operate thanks to magnets made of type II superconductors. Here, superconducting cables for the LHC are on display during a VIP visit.Abrikosov, who is now at the Argonne National Laboratory, was working at the Kapitsa Institute for Physical Problems in his native Moscow when he succeeded in formula...

  8. PRIze{sup TM} 1.2

    NONE

    1997-10-01

    PRIze{sup TM} 1.2 is a computer program that evaluates the improved oil recovery (IOR) potential of petroleum reservoirs including the use of horizontal wells. It was created in 1992 and has since been used in over 800 reservoir evaluations. The tool provides information on the feasibility of IOR processes based on reservoir parameters. PRIze{sup TM} makes predictions for chemical, gas injection and thermal IOR processes based on both vertical and horizontal wells. The program provides a uniform data entry screen that allows the user to input 42 average values of geological parameters, fluid properties and oil production mechanism information into a data file. The data can be used to provide a production forecast, and enable the user to establish, to a first order approximation, the economic viability of a given process.

  9. Gustav-Hertz-Prize for CERN Physicist

    2004-01-01

    Klaus Blaum, of GSI Darmstadt and project leader of the ISOLTRAP experiment at CERN, will receive the 2004 Gustav-Hertz-Prize for his outstanding work on the mass determination of unstable atomic nuclei. Blaum extended the measuring capability of the ISOLTRAP experiment at the ISOLDE facility, which studies short-lived isotopes, by installing a source of carbon clusters. Using these carbon clusters as mass reference allows researchers to obtain higher-precision and absolute atomic mass measurements which are important to understand the weak interaction and the synthesis of chemical elements. The Gustav-Hertz-Prize is awarded to outstanding young physicists and is endowed with 7500 euro. It will be awarded at the Spring Conference of the German Physical Society in Munich on 24 March.

  10. A new prize system for drug innovation.

    Gandjour, Afschin; Chernyak, Nadja

    2011-10-01

    We propose a new prize (reward) system for drug innovation which pays a price based on the value of health benefits accrued over time. Willingness to pay for a unit of health benefit is determined based on the cost-effectiveness ratio of palliative/nursing care. We solve the problem of limited information on the value of health benefits by mathematically relating reward size to the uncertainty of information including information on potential drug overuse. The proposed prize system offers optimal incentives to invest in research and development because it rewards the innovator for the social value of drug innovation. The proposal is envisaged as a non-voluntary alternative to the current patent system and reduces excessive marketing of innovators and generic drug producers. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Extending cosmology: the metric approach

    Mendoza, S.

    2012-01-01

    Comment: 2012, Extending Cosmology: The Metric Approach, Open Questions in Cosmology; Review article for an Intech "Open questions in cosmology" book chapter (19 pages, 3 figures). Available from: http://www.intechopen.com/books/open-questions-in-cosmology/extending-cosmology-the-metric-approach

  12. Special 2005 EPS HEPP prize colloquium

    CERN. Geneva; Wahl, Heinrich; Alvarez-Gaumé, Luís

    2005-01-01

    First evidence and measurement of direct CP violation by the NA31 experiment This is a colloquium celebrating the awarding of the 2005 EPS High Energy Particle Physics prize to Heinrich Wahl and the NA31 collaboration which showed for the first time Direct CP Violation in the decay of neutral K mesons. There will be an introduction to direct CP violation, followed by a review of experimental results.

  13. The Brain Prize 2014: complex human functions.

    Grigaityte, Kristina; Iacoboni, Marco

    2014-11-01

    Giacomo Rizzolatti, Stanislas Dehaene, and Trevor Robbins were recently awarded the 2014 Grete Lundbeck European Brain Research Prize for their 'pioneering research on higher brain mechanisms underpinning such complex human functions as literacy, numeracy, motivated behavior and social cognition, and for their effort to understand cognitive and behavioral disorders'. Why was their work highlighted? Is there anything that links together these seemingly disparate lines of research? Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. EPS HEPP Prize 2013: Certificate and Medal

    Rao, Achintya

    2013-01-01

    The 2013 High Energy and Particle Physics Prize, for an outstanding contribution to High Energy Physics, is awarded to the ATLAS and CMS collaborations, "for the discovery of a Higgs boson, as predicted by the Brout-Englert-Higgs mechanism", and to Michel Della Negra, Peter Jenni, and Tejinder Virdee, "for their pioneering and outstanding leadership roles in the making of the ATLAS and CMS experiments".

  15. Physics Nobel Prize (PNP in 2008

    José Maria Filardo Bassalo

    2009-08-01

    Full Text Available In this article we will talk about the Nobel Prize in Physics 2008, granted  to  the Japanese  physicists  Yoichiro  Nambu,  Makoto Kobayashi and Toshihide Maskawa,  for  their  discovery  of  the mechanisms involving strong interactions symmetries (quiral, by Nambu, and in weak interactions (charge-parity, by Kobayashi and Maskawa.

  16. The Abel Prize 2008-2012

    Piene, Ragni

    2014-01-01

    Covering the years 2008-2012, this book profiles the life and work of recent winners of the Abel Prize:   ·         John G. Thompson and Jacques Tits, 2008 ·         Mikhail Gromov, 2009 ·         John T. Tate Jr., 2010 ·         John W. Milnor, 2011 ·         Endre Szemerédi, 2012. The profiles feature autobiographical information as well as a description of each mathematician's work. In addition, each profile contains a complete bibliography, a curriculum vitae, as well as photos — old and new. As an added feature, interviews with the Laureates are presented on an accompanying web site (http://extras.springer.com/).   The book also presents a  history of the Abel Prize written by the historian Kim Helsvig, and includes a facsimile of a letter from Niels Henrik Abel, which is transcribed, translated into English, and placed into historical perspective by Christian Skau.    This book follows on The Abel Prize: 2003-2007, The First Five Years (Springer, 2010),...

  17. Cosmology and time

    Balbi Amedeo

    2013-09-01

    Full Text Available Time has always played a crucial role in cosmology. I review some of the aspects of the present cosmological model which are more directly related to time, such as: the definition of a cosmic time; the existence of typical timescales and epochs in an expanding universe; the problem of the initial singularity and the origin of time; the cosmological arrow of time.

  18. Inflation and quantum cosmology

    Linde, A.

    1991-01-01

    In this article a review of the present status of inflationary cosmology is given. We start with a discussion of the simplest version of the chaotic inflation scenario. Then we discuss some recent develoments in the inflationary cosmology, including the theory of a self-reproducing inflationary universe (eternal chaotic inflation). We do it with the help of stochastic approach to inflation. The results obtained within this approach are compared with the results obtained in the context of Euclidean quantum cosmology. (WL)

  19. The Bright Universe Cosmology

    Surdin, M.

    1980-01-01

    It is shown that viewed from the 'outside', our universe is a black hole. Hence the 'inside' cosmology considered is termed as the Bright Universe Cosmology. The model proposed avoids the singularities of cosmologies of the Big Bang variety, it gives a good account of the redshifts, the cosmic background radiation, the number counts; it also gives a satisfactory explanation of the 'large numbers coincidence' and of the variation in time of fundamental constants. (Auth.)

  20. Supersymmetry and cosmology

    Feng, Jonathan L.

    2005-01-01

    Cosmology now provides unambiguous, quantitative evidence for new particle physics. I discuss the implications of cosmology for supersymmetry and vice versa. Topics include: motivations for supersymmetry; supersymmetry breaking; dark energy; freeze out and WIMPs; neutralino dark matter; cosmologically preferred regions of minimal supergravity; direct and indirect detection of neutralinos; the DAMA and HEAT signals; inflation and reheating; gravitino dark matter; Big Bang nucleosynthesis; and the cosmic microwave background. I conclude with speculations about the prospects for a microscopic description of the dark universe, stressing the necessity of diverse experiments on both sides of the particle physics/cosmology interface

  1. The inflationary cosmology

    Sasaki, Misao

    1983-01-01

    We review the recent status of the inflationary cosmology. After exhibiting the essence of difficulties associated with the horizon, flatness and baryon number problems in the standard big-bang cosmology, we discuss that the inflationary universe scenario is one of the most plausible solutions to these fundamental cosmological problems. Since there are two qualitatively different versions of the inflationary universe scenario, we review each of them separately and discuss merits and demerits of each version. The Hawking radiation in de Sitter space is also reviewed since it may play an essential role in the inflationary cosmology. (author)

  2. Introduction to cosmology

    Roos, Matts

    2003-01-01

    The Third Edition of the hugely successful Introduction to Cosmology provides a concise, authoritative study of cosmology at an introductory level. Starting from elementary principles and the history of cosmology, the text carefully guides the student on to curved spacetimes, general relativity, black holes, cosmological models, particles and symmetries, and phase transitions. Extensively revised, this latest edition includes broader and updated coverage of distance measures, gravitational lensing and waves, dark energy and quintessence, the thermal history of the Universe, inflation,

  3. Axions in inflationary cosmology

    Linde, A.

    1991-01-01

    The problem of the cosmological constraints on the axion mass is re-examined. It is argued that in the context of inflationary cosmology the constraint m a > or approx.10 -5 eV can be avoided even when the axion perturbations produced during inflation are taken into account. It is shown also that in most axion models the effective parameter f a rapidly changes during inflation. This modifies some earlier statements concerning isothermal perturbations in the axion cosmology. A hybrid inflation scenario is proposed which combines some advantages of chaotic inflation with specific features of new and/or extended inflation. Its implications for the axion cosmology are discussed. (orig.)

  4. Prizes for innovation of new medicines and vaccines.

    Love, James; Hubbard, Tim

    2009-01-01

    This article argues that prizes can help stimulate medical innovation, control costs and ensure greater access to new medicines and vaccines. The authors explore four increasingly ambitious prize options to reward medical innovation, each addressing flaws in the current patent system. The first option promotes innovation through a large prize fund linked to the impact on health outcomes; the second option rewards the sharing of knowledge, data, and technology with open source dividends; the third option awards prizes for interim benchmarks and discrete technical problems; and the final option removes the exclusive right to use patented inventions in upstream research in favor of prizes. The authors conclude that a system of prizes to reward drug development would break the link between R&D incentives and product prices, and that such a reform is needed to improve innovation and access to new medicines and vaccines.

  5. QUALITY LEADERS - LEARNING FROM THE DEMING PRIZE WINNERS IN INDIA

    Jagadeesh Rajashekharaiah

    2014-01-01

    Different governments and professional agencies have set up a number of awards to recognize and reward quality initiatives. Deming Prize is one such award and ever since it was open for companies from outside Japan, maximum number of winning companies are from India, with 20 companies winning the Deming Prize and four among them also winning the Deming Grand Prize. This paper traces the path taken by these companies to know how these companies embarked a journey of Total Quality Management (T...

  6. Wormholes and cosmology

    Klebanov, I.; Susskind, L.

    1988-10-01

    We review Coleman's wormhole mechanism for the vanishing of the cosmological constant. We find a discouraging result that wormholes much bigger than the Planck size are generated. We also consider the implications of the wormhole theory for cosmology. 7 refs., 2 figs

  7. Particle physics and cosmology

    Ellis, J.; Nanopoulos, D.

    1983-01-01

    The authors describe the connection between cosmology and particle physics in an introductory way. In this connection the big bang theory and unified gauge models of strong, electromagnetic, and weak interactions are considered. Furthermore cosmological nucleosynthesis is discussed in this framework, and the problem of cosmic neutrinos is considered with special regards to its rest mass. (HSI).

  8. Cosmology and particle physics

    Turner, M.S.

    1986-01-01

    Progress in cosmology has become linked to progress in elementary particle physics. In these six lectures, the author illustrates the two-way nature of the interplay between these fields by focusing on a few selected topics. In the next section the author reviews the standard cosmology, especially concentrating on primordial nucleosynthesis and discusses how the standard cosmology has been used to place constraints on the properties of various particles. Grand Unification makes two striking predictions: (i) B non-conservation; (ii) the existence of stable, superheavy magnetic monopoles. Both have had great cosmological impact. In the following section the author discusses baryogenesis, the very attractive scenario in which the B,C,CP violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and the present baryon-to-photon ratio. Monopoles are a cosmological disaster and an astrophysicist's delight. In Section 4 discusses monopoles, cosmology, and astrophysics. In the fourth lecture the author discusses how a very early (t≤10/sup -34/ sec) phase transition associated with spontaneous symmetry breaking (SSB) has the potential to explain a handful of very fundamental cosmological facts, facts which can be accommodated by the standard cosmology, but which are not ''explained'' by it. The fifth lecture is devoted to a discussion of structure formation in the universe

  9. New Challenges for Cosmology

    van de Weygaert, Rien; van Albada, Tjeerd S.

    1996-01-01

    A detailed account of the ways in which a square kilometer array could further cosmological research. Observational and theoretical studies of the large scale structure and morphology of the local universe are reviewed against the potential capabilities of a new generation telescope. Cosmological

  10. The encyclopedia of cosmology

    Barkana, Rennan; Tsujikawa, Shinji; Kim, Jihn E; Nagamine, Kentaro

    2018-01-01

    The Encyclopedia of Cosmology, in four volumes, is a major, long-lasting, seminal reference at the graduate student level, laid out by the most prominent, respected researchers in the general field of Cosmology. These volumes will be a comprehensive review of the most important concepts and current status in the field, covering both theory and observation.

  11. Astroparticle physics and cosmology

    Senjanovic, G.; Smirnov, A.Yu.; Thompson, G.

    2001-01-01

    In this volume a wide spectrum of topics of modern astroparticle physics, such as neutrino astrophysics, dark matter of the universe, high energy cosmic rays, topological defects in cosmology, γ-ray bursts, phase transitions at high temperatures, is covered. The articles written by top level experts in the field give a comprehensive view of the state-of-the-art of modern cosmology

  12. Perspectives in cosmology

    Vilenkin, Alexander, E-mail: vilenkin@cosmos.phy.tufts.ed [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)

    2010-01-01

    The 'new standard cosmology', based on the theory of inflation, has very impressive observational support. I review some outstanding problems of the new cosmology and the global view of the universe - the multiverse - that it suggests. I focus in particular on prospects for further observational tests of inflation and of the multiverse.

  13. Perspectives in cosmology

    Vilenkin, Alexander

    2010-01-01

    The n ew standard cosmology , based on the theory of inflation, has very impressive observational support. I review some outstanding problems of the new cosmology and the global view of the universe - the multiverse - that it suggests. I focus in particular on prospects for further observational tests of inflation and of the multiverse.

  14. Astroparticle physics and cosmology

    Senjanovic, G; Smirnov, A Yu; Thompson, G [eds.

    2001-11-15

    In this volume a wide spectrum of topics of modern astroparticle physics, such as neutrino astrophysics, dark matter of the universe, high energy cosmic rays, topological defects in cosmology, {gamma}-ray bursts, phase transitions at high temperatures, is covered. The articles written by top level experts in the field give a comprehensive view of the state-of-the-art of modern cosmology.

  15. Antimatter and cosmology

    Stecker, F.W.

    1989-01-01

    This paper discusses two aspects of antimatter and cosmology: 1. the fundamental cosmological question as to whether antimatter plays an equally important role as matter in the universe (overall baryon symmetry), and 2. cosmic-ray antimatter tests for the nature of the dark matter in the universe. (orig.)

  16. Neutrino mass from Cosmology

    Lesgourgues, Julien

    2012-01-01

    Neutrinos can play an important role in the evolution of the Universe, modifying some of the cosmological observables. In this contribution we summarize the main aspects of cosmological relic neutrinos and we describe how the precision of present cosmological data can be used to learn about neutrino properties, in particular their mass, providing complementary information to beta decay and neutrinoless double-beta decay experiments. We show how the analysis of current cosmological observations, such as the anisotropies of the cosmic microwave background or the distribution of large-scale structure, provides an upper bound on the sum of neutrino masses of order 1 eV or less, with very good perspectives from future cosmological measurements which are expected to be sensitive to neutrino masses well into the sub-eV range.

  17. A taste of cosmology

    Verde, L.

    2011-01-01

    This is the summary of two lectures that aim to give an overview of cosmology. I will not try to be toa rigorous in derivations, nor to give a full historical overview. The idea is to provide a 'taste' of cosmology and some of the interesting topics it covers. The standard cosmological model is presented and I highlight the successes of cosmology over the past decade or so. Keys to the development of the standard cosmological model are observations of the cosmic microwave background and of large-scale structure, which are introduced. Inflation and dark energy and the outlook for the future are also discussed. Slides from the lectures are available from the school web site: physicschool.web.cern.ch/PhysicSchool/CLASHEP/CLASHEP2011/. (author)

  18. Classical and quantum cosmology

    Calcagni, Gianluca

    2017-01-01

    This comprehensive textbook is devoted to classical and quantum cosmology, with particular emphasis on modern approaches to quantum gravity and string theory and on their observational imprint. It covers major challenges in theoretical physics such as the big bang and the cosmological constant problem. An extensive review of standard cosmology, the cosmic microwave background, inflation and dark energy sets the scene for the phenomenological application of all the main quantum-gravity and string-theory models of cosmology. Born of the author's teaching experience and commitment to bridging the gap between cosmologists and theoreticians working beyond the established laws of particle physics and general relativity, this is a unique text where quantum-gravity approaches and string theory are treated on an equal footing. As well as introducing cosmology to undergraduate and graduate students with its pedagogical presentation and the help of 45 solved exercises, this book, which includes an ambitious bibliography...

  19. A Taste of Cosmology

    Verde, L.

    2013-06-27

    This is the summary of two lectures that aim to give an overview of cosmology. I will not try to be too rigorous in derivations, nor to give a full historical overview. The idea is to provide a "taste" of cosmology and some of the interesting topics it covers. The standard cosmological model is presented and I highlight the successes of cosmology over the past decade or so. Keys to the development of the standard cosmological model are observations of the cosmic microwave background and of large-scale structure, which are introduced. Inflation and dark energy and the outlook for the future are also discussed. Slides from the lectures are available from the school website: physicschool.web.cern.ch/PhysicSchool/CLASHEP/CLASHEP2011/.

  20. Einstein and cosmology

    Gekman, O.

    1982-01-01

    The brief essay of the development of the main ideas of relativistic cosmology is presented. The Einstein's cosmological work about the Universe - ''Cosmological considerations in connection with the general relativity theory'' - gave the basis to all further treatments in this field. In 1922 A. Friedman's work appeared, in which the first expanding Universe model was proposed as a solution of the Einstein field equations. The model was spherically closed, but its curvature radius was a function of time. About 1955 the searches for anisotropic homogeneous solutions to Einstein field equation began. It turned out that isotropic cosmological models are unstable in general. The predominant part of them transform to anisotropic at insignificant breaking of isotropy. The discovery of isotropic background cosmic radiation in 1965, along with the Hubble low of the Universe expansion, served as the direct confirmation of cosmology based on the Einstein theory

  1. Arthroscopy Journal Prizes Are Major Decisions.

    Lubowitz, James H; Brand, Jefferson C; Provencher, Matthew T; Rossi, Michael J

    2016-01-01

    According to the Harvard Business Review, the optimal number of people in a decision-making group is no more than 8. Thus, it is no surprise that 18 Arthroscopy journal associate editors had difficulty making a major decision. In the end, 18 editors did successfully select the 2015 winner of the Best Comparative Study Prize. All studies have limitations, but from a statistical standpoint, the editors believe that the conclusions of the winning study are likely correct. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  2. On the Human Aspect of Nobel Prize

    Durand, G.

    1990-10-01

    One night, Nico invited for dinner all his postdoc and graduate students, in a German restaurant close to Harvard Square. Just before we were to pay for our meal, he told us: "Tomorrow, we shall know the Nobel prize winner. Can you people make a guess on his name?" All my colleagues nominated great physicists. In my turn, I suggested naively (and perhaps nationalistically) the name of Alfred Kastler who had been my thesis adviser. "Come on," joked Nico, "I know a lot of physicists who would deserve it much better.."

  3. Autophagy: one more Nobel Prize for yeast

    Andreas Zimmermann

    2016-12-01

    Full Text Available The recent announcement of the 2016 Nobel Prize in Physiology or Medicine, awarded to Yoshinori Ohsumi for the discoveries of mechanisms governing autophagy, underscores the importance of intracellular degradation and recycling. At the same time, it further cements yeast, in which this field decisively developed, as a prolific model organism. Here we provide a quick historical overview that mirrors both the importance of autophagy as a conserved and essential process for cellular life and death as well as the crucial role of yeast in its mechanistic characterization.

  4. Smoot Cosmology Group

    of The Big Bang - the theory of how the universe was created. Smoot received the Nobel Prize for his matter and mysterious gaping voids - evolved this way. The Big Bang, COBE, and the Relic Radiation of and the structure of space-time. These observations have provided increased support for the big bang

  5. BMS in cosmology

    Kehagias, A.; Riotto, A.

    2016-01-01

    Symmetries play an interesting role in cosmology. They are useful in characterizing the cosmological perturbations generated during inflation and lead to consistency relations involving the soft limit of the statistical correlators of large-scale structure dark matter and galaxies overdensities. On the other hand, in observational cosmology the carriers of the information about these large-scale statistical distributions are light rays traveling on null geodesics. Motivated by this simple consideration, we study the structure of null infinity and the associated BMS symmetry in a cosmological setting. For decelerating Friedmann-Robertson-Walker backgrounds, for which future null infinity exists, we find that the BMS transformations which leaves the asymptotic metric invariant to leading order. Contrary to the asymptotic flat case, the BMS transformations in cosmology generate Goldstone modes corresponding to scalar, vector and tensor degrees of freedom which may exist at null infinity and perturb the asymptotic data. Therefore, BMS transformations generate physically inequivalent vacua as they populate the universe at null infinity with these physical degrees of freedom. We also discuss the gravitational memory effect when cosmological expansion is taken into account. In this case, there are extra contribution to the gravitational memory due to the tail of the retarded Green functions which are supported not only on the light-cone, but also in its interior. The gravitational memory effect can be understood also from an asymptotic point of view as a transition among cosmological BMS-related vacua.

  6. Unimodular-mimetic cosmology

    Nojiri, S; Odintsov, S D; Oikonomou, V K

    2016-01-01

    We combine the unimodular gravity and mimetic gravity theories into a unified theoretical framework, which is proposed to provide a suggestive proposal for a framework that may assist in the discussion and search for a solution to the cosmological constant problem and the dark matter issue. After providing the formulation of the unimodular mimetic gravity and investigating all the new features that the vacuum unimodular gravity implies, by using the underlying reconstruction method, we realize some well known cosmological evolutions, with some of these being exotic for the ordinary Einstein–Hilbert gravity. Specifically we provide the vacuum unimodular mimetic gravity description of the de Sitter cosmology and of the perfect fluid with constant equation of state cosmology. As we demonstrate, these cosmologies can be realized by vacuum mimetic unimodular gravity, without the existence of any matter fluid source. Moreover, we investigate how cosmologically viable cosmologies, which are compatible with the recent observational data, can be realized by the vacuum unimodular mimetic gravity. Since in some cases, a graceful exit from inflation problem might exist, we provide a qualitative description of the mechanism that can potentially generate the graceful exit from inflation in these theories, by searching for the unstable de Sitter solutions in the context of unimodular mimetic theories of gravity. (paper)

  7. BMS in cosmology

    Kehagias, A. [Physics Division, National Technical University of Athens, 15780 Zografou Campus, Athens (Greece); Riotto, A. [Department of Theoretical Physics,24 quai E. Ansermet, CH-1211 Geneva 4 (Switzerland); Center for Astroparticle Physics (CAP),24 quai E. Ansermet, CH-1211 Geneva 4 (Switzerland)

    2016-05-25

    Symmetries play an interesting role in cosmology. They are useful in characterizing the cosmological perturbations generated during inflation and lead to consistency relations involving the soft limit of the statistical correlators of large-scale structure dark matter and galaxies overdensities. On the other hand, in observational cosmology the carriers of the information about these large-scale statistical distributions are light rays traveling on null geodesics. Motivated by this simple consideration, we study the structure of null infinity and the associated BMS symmetry in a cosmological setting. For decelerating Friedmann-Robertson-Walker backgrounds, for which future null infinity exists, we find that the BMS transformations which leaves the asymptotic metric invariant to leading order. Contrary to the asymptotic flat case, the BMS transformations in cosmology generate Goldstone modes corresponding to scalar, vector and tensor degrees of freedom which may exist at null infinity and perturb the asymptotic data. Therefore, BMS transformations generate physically inequivalent vacua as they populate the universe at null infinity with these physical degrees of freedom. We also discuss the gravitational memory effect when cosmological expansion is taken into account. In this case, there are extra contribution to the gravitational memory due to the tail of the retarded Green functions which are supported not only on the light-cone, but also in its interior. The gravitational memory effect can be understood also from an asymptotic point of view as a transition among cosmological BMS-related vacua.

  8. CERN exhibition wins yet another design prize

    Joannah Caborn Wengler

    2012-01-01

    The “Universe of Particles” exhibition in CERN’s Globe wins the silver design prize from the German direct business communications association FAMAB.   Not only do tens of thousands of people visit the “Universe of Particles” exhibition each year, but juries for design prizes are crossing its threshold more and more frequently too. In 2011 alone it claimed 8 awards, including winning outright the 2011 Annual Multimedia award, the iF Communication Design for Corporate Architecture award and the Modern Decoration Media award (the Bulletin already reported on some of these in July 2011). The FAMAB award is the latest to join the prestigious list. The jury of FAMAB’s “ADAM 2011” award was particularly impressed by the hands-on nature of the exhibition, which encourages visitors to get interested in science. They also appreciated the way that the space in the Globe is not just a container for the exhibits, but itself ...

  9. Robert Aymar awarded Global Energy prize

    2006-01-01

    CERN Director-General Robert Aymar was recently named one of three laureates of the 2006 Global Energy International Prize for 'the development of scientific and engineering foundation for the ITER project.' ITER is an experiment planned to be built in Europe at Cadarache (South of France) and designed to show the scientific and technological feasibility of a full-scale fusion power reactor. The other two laureates, who worked with Aymar on the project, are former President of the ITER Council, Russian Academician Evgeny Velikhov, and Japan's Dr Masaji Yoshikawa, ITER's former Vice President. Aymar headed ITER from 1994 to 2003. 'This prize is not only a great honour for me and my friends and colleagues of many years at ITER, Evgeny Velikhov and Masaji Yoshikawa,' Aymar said. 'It is above all a recognition of the effort of all those who have been involved with the ITER project and worked over the years to ensure the first step in proving that fusion will provide a new sustainable energy source for the plane...

  10. Briton wins Nobel physics prize for work on superfluids

    Connor, S

    2003-01-01

    A British born scientist, Anthony Leggett, 65, has jointly won this year's Nobel prize in physics for research into the arcane area of superfluids - when matter behaves in its lowest and most ordered state. He shares the 800,000 pounds prize with two Russian physicists who have worked in the field of superconductivity - when electrical conductors lose resistance (1/2 page).

  11. 2008 Nobel prize in Medicine for discoverers of HIV

    Berkhout Ben

    2008-10-01

    Full Text Available Abstract Françoise Barré-Sinoussi and Luc Montagnier, codiscoverers of HIV, the causative agent of AIDS, have been awarded the 2008 Nobel Prize in Physiology or Medicine. They share this prize with Harald zur Hausen who was responsible for establishing the link between human papilloma virus infection and cervical carcinoma.

  12. 2008 Nobel prize in Medicine for discoverers of HIV

    Lever, Andrew M. L.; Berkhout, Ben

    2008-01-01

    ABSTRACT: Francoise Barre-Sinoussi and Luc Montagnier, codiscoverers of HIV, the causative agent of AIDS, have been awarded the 2008 Nobel Prize in Physiology or Medicine. They share this prize with Harald zur Hausen who was responsible for establishing the link between human papilloma virus

  13. Nobel physics prize to Charpak for inventing particle detectors

    Schwarzschild, B.

    1993-01-01

    This article describes the work of Georges Charpak of France leading to his receipt of the 1992 Nobel Prize in Physics. The Nobel Prize was awarded to Charpak open-quotes for his invention and development of particle detectors, in particular the multiwire proportional chamber.close quotes Historical aspects of Charpak's life and research are given

  14. Neutrino properties from cosmology

    Hannestad, S.

    2013-01-01

    In recent years precision cosmology has become an increasingly powerful probe of particle physics. Perhaps the prime example of this is the very stringent cosmological upper bound on the neutrino mass. However, other aspects of neutrino physics, such as their decoupling history and possible non......-standard interactions, can also be probed using observations of cosmic structure. Here, I review the current status of cosmological bounds on neutrino properties and discuss the potential of future observations, for example by the recently approved EUCLID mission, to precisely measure neutrino properties....

  15. Cosmology and particle physics

    Barrow, J.D.

    1982-01-01

    A brief overview is given of recent work that integrates cosmology and particle physics. The observational data regarding the abundance of matter and radiation in the Universe is described. The manner in which the cosmological survival density of stable massive particles can be calculated is discussed along with the process of cosmological nucleosynthesis. Several applications of these general arguments are given with reference to the survival density of nucleons, neutrinos and unconfined fractionally charge particles. The use of nucleosynthesis to limit the number of lepton generations is described together with the implications of a small neutrino mass for the origin of galaxies and clusters. (Auth.)

  16. Cosmology and particle physics

    Steigman, G [California Univ., Santa Barbara (USA). Inst. for Theoretical Physics; Bartol Research Foundation, Newark, Delaware (USA))

    1982-01-29

    The cosmic connections between physics on the very largest and very smallest scales are reviewed with an emphasis on the symbiotic relation between elementary particle physics and cosmology. After a review of the early Universe as a cosmic accelerator, various cosmological and astrophysical constraints on models of particle physics are outlined. To illustrate this approach to particle physics via cosmology, reference is made to several areas of current research: baryon non-conservation and baryon asymmetry; free quarks, heavy hadrons and other exotic relics; primordial nucleosynthesis and neutrino masses.

  17. Neutrino properties from cosmology

    CERN. Geneva

    2013-01-01

    Future, massive large-scale structure survey have been presented and approved.On the theory side, a significant effort has bene devoted to achieve better modeling of small scale clustering that is of cosmological non-linearities. As a result it has become clear that forthcoming cosmological data have enough statitsical power to detect the effect of non-zero neutrino mass (even at the lower mass scale limit imposed by oscillations) and to constrain the absolute neutrino mass scale.Cosmological data can also constrain the numb...

  18. The cosmological constant problem

    Dolgov, A.D.

    1989-05-01

    A review of the cosmological term problem is presented. Baby universe model and the compensating field model are discussed. The importance of more accurate data on the Hubble constant and the Universe age is stressed. 18 refs

  19. Time in contemporary cosmology

    Mavrides, Stamatia

    1980-01-01

    Cosmological time is defined, as is coordinated universal time against local times of special relativity. The problems of time and matter, age of the universe, Goedel models, arrow of time, are also discussed [fr

  20. Quantum cosmological models

    Coule, D H

    2005-01-01

    We contrast the initial condition requirements of various contemporary cosmological models including inflationary and bouncing cosmologies. Canonical quantization of general relativity is used, as a first approximation to full quantum gravity, to determine whether suitable initial conditions are present. Various proposals such as Hartle-Hawking's 'no boundary' or tunnelling boundary conditions are assessed on grounds of naturalness and fine tuning. Alternatively, a quiescent initial state or an initial closed timelike curve 'time machine' is considered. Possible extensions to brane models are also addressed. Further ideas about universe creation from a meta-universe are outlined. Semiclassical and time asymmetry requirements of cosmology are briefly discussed and contrasted with the black-hole final-state proposal. We compare the recent loop quantum cosmology of Bojowald and co-workers with these earlier schemes. A number of possible difficulties and limitations are outlined. (topical review)

  1. Cosmological Probes for Supersymmetry

    Maxim Khlopov

    2015-05-01

    Full Text Available The multi-parameter character of supersymmetric dark-matter models implies the combination of their experimental studies with astrophysical and cosmological probes. The physics of the early Universe provides nontrivial effects of non-equilibrium particles and primordial cosmological structures. Primordial black holes (PBHs are a profound signature of such structures that may arise as a cosmological consequence of supersymmetric (SUSY models. SUSY-based mechanisms of baryosynthesis can lead to the possibility of antimatter domains in a baryon asymmetric Universe. In the context of cosmoparticle physics, which studies the fundamental relationship of the micro- and macro-worlds, the development of SUSY illustrates the main principles of this approach, as the physical basis of the modern cosmology provides cross-disciplinary tests in physical and astronomical studies.

  2. Cosmology solved? Maybe

    Turner, Michael S.

    1999-01-01

    For two decades the hot big-bang model as been referred to as the standard cosmology - and for good reason. For just as long cosmologists have known that there are fundamental questions that are not answered by the standard cosmology and point to a grander theory. The best candidate for that grander theory is inflation + cold dark matter. It holds that the Universe is flat, that slowly moving elementary particles left over from the earliest moments provide the cosmic infrastructure, and that the primeval density inhomogeneities that seed all the structure arose from quantum fluctuations. There is now prima facie evidence that supports two basic tenets of this paradigm. An avalanche of high-quality cosmological observations will soon make this case stronger or will break it. Key questions remain to be answered; foremost among them are: identification and detection of the cold dark matter particles and elucidation of the dark-energy component. These are exciting times in cosmology!

  3. Mirror fermions and cosmology

    Senjanovic, G.; Virginia Polytechnic Inst. and State Univ., Blacksburg

    1984-07-01

    Extended supersymmetry, Kaluza-Klein theory and family unification all suggest the existence of mirror fermions, with same quantum numbers but opposite helicities from ordinary fermions. The laboratory and especially cosmological implications of such particles are reviewed and summarized. (author)

  4. Cosmology. A first course

    Lachieze-Rey, Marc

    This book delivers a quantitative account of the science of cosmology, designed for a non-specialist audience. The basic principles are outlined using simple maths and physics, while still providing rigorous models of the Universe. It offers an ideal introduction to the key ideas in cosmology, without going into technical details. The approach used is based on the fundamental ideas of general relativity such as the spacetime interval, comoving coordinates, and spacetime curvature. It provides an up-to-date and thoughtful discussion of the big bang, and the crucial questions of structure and galaxy formation. Questions of method and philosophical approaches in cosmology are also briefly discussed. Advanced undergraduates in either physics or mathematics would benefit greatly from use either as a course text or as a supplementary guide to cosmology courses.

  5. Introduction to cosmology

    Ryden, Barbara

    2017-01-01

    This second edition of Introduction to Cosmology is an exciting update of an award-winning textbook. It is aimed primarily at advanced undergraduate students in physics and astronomy, but is also useful as a supplementary text at higher levels. It explains modern cosmological concepts, such as dark energy, in the context of the Big Bang theory. Its clear, lucid writing style, with a wealth of useful everyday analogies, makes it exceptionally engaging. Emphasis is placed on the links between theoretical concepts of cosmology and the observable properties of the universe, building deeper physical insights in the reader. The second edition includes recent observational results, fuller descriptions of special and general relativity, expanded discussions of dark energy, and a new chapter on baryonic matter that makes up stars and galaxies. It is an ideal textbook for the era of precision cosmology in the accelerating universe.

  6. Tensors, relativity, and cosmology

    Dalarsson, Mirjana

    2015-01-01

    Tensors, Relativity, and Cosmology, Second Edition, combines relativity, astrophysics, and cosmology in a single volume, providing a simplified introduction to each subject that is followed by detailed mathematical derivations. The book includes a section on general relativity that gives the case for a curved space-time, presents the mathematical background (tensor calculus, Riemannian geometry), discusses the Einstein equation and its solutions (including black holes and Penrose processes), and considers the energy-momentum tensor for various solutions. In addition, a section on relativistic astrophysics discusses stellar contraction and collapse, neutron stars and their equations of state, black holes, and accretion onto collapsed objects, with a final section on cosmology discussing cosmological models, observational tests, and scenarios for the early universe. This fully revised and updated second edition includes new material on relativistic effects, such as the behavior of clocks and measuring rods in m...

  7. Magnetohydrodynamics and Plasma Cosmology

    Kleidis, Kostas; Kuiroukidis, Apostolos; Papadopoulos, Demetrios; Vlahos, Loukas

    2007-09-01

    We study the linear magnetohydrodynamic (MHD) equations, both in the Newtonian and the general-relativistic limit, as regards a viscous magnetized fluid of finite conductivity and discuss instability criteria. In addition, we explore the excitation of cosmological perturbations in anisotropic spacetimes, in the presence of an ambient magnetic field. Acoustic, electromagnetic (e/m) and fast-magnetosonic modes, propagating normal to the magnetic field, can be excited, resulting in several implications of cosmological significance.

  8. Cosmology Then and Now

    Novikov, I.D.

    1999-01-01

    In this talk a brief survey has been carried out on the development of cosmology from the days Leopold Infeld was active in the field up to the present. Attention in particular is paid to the history of our knowledge of Hubble's expansion, of the cosmological constant, of the average density of matter and its distribution, and of the related issue of possible types of matter in the Universe. (author)

  9. Cosmological phase transitions

    Kolb, E.W.

    1993-10-01

    If modern ideas about the role of spontaneous symmetry breaking in fundamental physics are correct, then the Universe should have undergone a series of phase transitions early in its history. The study of cosmological phase transitions has become an important aspect of early-Universe cosmology. In this lecture I review some very recent work on three aspects of phase transitions: the electroweak transition, texture, and axions

  10. A Planck Vacuum Cosmology

    Daywitt W. C.

    2009-04-01

    Full Text Available Both the big-bang and the quasi-steady-state cosmologies originate in some type of Planck state. This paper presents a new cosmological theory based on the Planck- vacuum negative-energy state, a state consisting of a degenerate collection of negative- energy Planck particles. A heuristic look at the Einstein field equation provides a con- vincing argument that such a vacuum state could provide a theoretical explanation for the visible universe.

  11. Cosmological Models and Stability

    Andersson, Lars

    Principles in the form of heuristic guidelines or generally accepted dogma play an important role in the development of physical theories. In particular, philosophical considerations and principles figure prominently in the work of Albert Einstein. As mentioned in the talk by Jiří Bičák at this conference, Einstein formulated the equivalence principle, an essential step on the road to general relativity, during his time in Prague 1911-1912. In this talk, I would like to discuss some aspects of cosmological models. As cosmology is an area of physics where "principles" such as the "cosmological principle" or the "Copernican principle" play a prominent role in motivating the class of models which form part of the current standard model, I will start by comparing the role of the equivalence principle to that of the principles used in cosmology. I will then briefly describe the standard model of cosmology to give a perspective on some mathematical problems and conjectures on cosmological models, which are discussed in the later part of this paper.

  12. Conductive concrete wins Popular Science prize

    Anon.

    1997-06-01

    A conductive concrete developed by a research team at IRC (Institute for Research in Construction, National Research Council of Canada) has won a prize in the home technology category because of its possible use in heating homes. Following the award, there have been a number of inquiries regarding possible applications for the concrete. Greatest interests in the concrete have been in its potential to heat buildings by using it as flooring. Other possible applications included de-icing pavements to building warming pads for parking aircraft. Essentially, carbon fibres and conductive particles are added to a concrete mix in such a quantity that they form a network within the mix, ensuring high electrical conductivity. A demonstration project is underway to build a 20 by 80 foot conductive concrete pad to test the material`s capability as a snow removal and de-icing tool.

  13. BOOK REVIEW: Observational Cosmology Observational Cosmology

    Howell, Dale Andrew

    2013-04-01

    Observational Cosmology by Stephen Serjeant fills a niche that was underserved in the textbook market: an up-to-date, thorough cosmology textbook focused on observations, aimed at advanced undergraduates. Not everything about the book is perfect - some subjects get short shrift, in some cases jargon dominates, and there are too few exercises. Still, on the whole, the book is a welcome addition. For decades, the classic textbooks of cosmology have focused on theory. But for every Sunyaev-Zel'dovich effect there is a Butcher-Oemler effect; there are as many cosmological phenomena established by observations, and only explained later by theory, as there were predicted by theory and confirmed by observations. In fact, in the last decade, there has been an explosion of new cosmological findings driven by observations. Some are so new that you won't find them mentioned in books just a few years old. So it is not just refreshing to see a book that reflects the new realities of cosmology, it is vital, if students are to truly stay up on a field that has widened in scope considerably. Observational Cosmology is filled with full-color images, and graphs from the latest experiments. How exciting it is that we live in an era where satellites and large experiments have gathered so much data to reveal astounding details about the origin of the universe and its evolution. To have all the latest data gathered together and explained in one book will be a revelation to students. In fact, at times it was to me. I've picked up modern cosmological knowledge through a patchwork of reading papers, going to colloquia, and serving on grant and telescope allocation panels. To go back and see them explained from square one, and summarized succinctly, filled in quite a few gaps in my own knowledge and corrected a few misconceptions I'd acquired along the way. To make room for all these graphs and observational details, a few things had to be left out. For one, there are few derivations

  14. Who can get the next Nobel Prize in infectious diseases?

    Onder Ergonul

    2016-04-01

    Full Text Available The aim of this paper is to deliver a perspective on future Nobel prizes by reviewing the features of Nobel prizes awarded in the infectious diseases-related (IDR field over the last 115 years. Thirty-three out of 106 Nobel prizes (31% in Physiology or Medicine have been awarded for IDR topics. Out of 58 Nobel laureates for IDR topics, two have been female; 67% have been medical doctors. The median age of Nobel laureates in Physiology or Medicine was found to be lower than the median age of laureates in Literature (p < 0.001. Since the Second World War, US-affiliated scientists have dominated the Nobel prizes (53%; however before 1945, German scientists did so (p = 0.005. The new antimicrobials received Nobel prizes until 1960; however no treatment study was awarded the Prize until the discovery of artemisinin and ivermectin, for which the Nobel Prize was awarded in 2015. Collaborative works have increasingly been appreciated. In the future, more female laureates would be expected in the IDR field. Medical graduates and scientists involved in multi-institutional and multidisciplinary collaborative efforts seem to have an advantage.

  15. On the cosmological gravitational waves and cosmological distances

    Belinski, V. A.; Vereshchagin, G. V.

    2018-03-01

    We show that solitonic cosmological gravitational waves propagated through the Friedmann universe and generated by the inhomogeneities of the gravitational field near the Big Bang can be responsible for increase of cosmological distances.

  16. Quark matter and cosmology

    Schramm, D.N.; Fields, B.; Thomas, D.

    1992-01-01

    The possible implications of the quark-hadron transition for cosmology are explored. Possible surviving signatures are discussed. In particular, the possibility of generating a dark matter candidate such as strange nuggets or planetary mass black holes is noted. Much discussion is devoted to the possible role of the transition for cosmological nucleosynthesis. It is emphasized that even an optimized first order phase transition will not significantly alter the nucleosynthesis constraints on the cosmological baryon density nor on neutrino counting. However, it is noted that Be and B observations in old stars may eventually be able to be a signature of a cosmologically significant quark-hadron transition. It is pointed out that the critical point in this regard is whether the observed B/Be ratio can be produced by spallation processes or requires cosmological input. Spallation cannot produce a B/Be ratio below 7.6. A supporting signature would be Be and B ratios to oxygen that greatly exceed galactic values. At present, all data is still consistent with a spallagenic origin

  17. Inhomogeneous anisotropic cosmology

    Kleban, Matthew; Senatore, Leonardo

    2016-01-01

    In homogeneous and isotropic Friedmann-Robertson-Walker cosmology, the topology of the universe determines its ultimate fate. If the Weak Energy Condition is satisfied, open and flat universes must expand forever, while closed cosmologies can recollapse to a Big Crunch. A similar statement holds for homogeneous but anisotropic (Bianchi) universes. Here, we prove that arbitrarily inhomogeneous and anisotropic cosmologies with “flat” (including toroidal) and “open” (including compact hyperbolic) spatial topology that are initially expanding must continue to expand forever at least in some region at a rate bounded from below by a positive number, despite the presence of arbitrarily large density fluctuations and/or the formation of black holes. Because the set of 3-manifold topologies is countable, a single integer determines the ultimate fate of the universe, and, in a specific sense, most 3-manifolds are “flat” or “open”. Our result has important implications for inflation: if there is a positive cosmological constant (or suitable inflationary potential) and initial conditions for the inflaton, cosmologies with “flat” or “open” topology must expand forever in some region at least as fast as de Sitter space, and are therefore very likely to begin inflationary expansion eventually, regardless of the scale of the inflationary energy or the spectrum and amplitude of initial inhomogeneities and gravitational waves. Our result is also significant for numerical general relativity, which often makes use of periodic (toroidal) boundary conditions.

  18. Recipients of 2013 EPS High Energy & Particle Physics Prize

    ATLAS, Experiment

    2014-01-01

    (From left) Joe Incandela, Peter Higgs, Francois Englert, Tejinder Virdee, Dave Charlton, and Peter Jenni. Higgs and Englert gave the prizes to the recipients of the 2013 European Physical Society's High Energy and Particle Physics Prize, for an outstanding contribution to high energy physics. "For the discovery of a Higgs boson, as predicted by the Brout-Englert-Higgs mechanism," the prize was awarded to the ATLAS and CMS collaborations. Spokesperson for CMS, Incandela, and Spokesperson for ATLAS, Charlton, accepted the awards on their collaborations' behalf. "For their pioneering and outstanding leadership roles in the making of the ATLAS and CMS experiments," the prize was awarded to Jenni, Virdee, and Michel Della Negra (not present). Image: ATLAS

  19. QUALITY LEADERS - LEARNING FROM THE DEMING PRIZE WINNERS IN INDIA

    Jagadeesh Rajashekharaiah

    2014-09-01

    Full Text Available Different governments and professional agencies have set up a number of awards to recognize and reward quality initiatives. Deming Prize is one such award and ever since it was open for companies from outside Japan, maximum number of winning companies are from India, with 20 companies winning the Deming Prize and four among them also winning the Deming Grand Prize. This paper traces the path taken by these companies to know how these companies embarked a journey of Total Quality Management (TQM and reached their goal of winning the prestigious Deming Prize. The common working principles of these companies and the various tools and techniques used by them are described in a concise manner in this paper. Further, the paper highlights the lessons from these companies to inspire others. The data taken from the respective websites of the companies has been used to list out the objectives, methodologies, and the benefits accrued by the companies.

  20. Ocular Injuries: Another Example of the Heavy Prize of Terrorism

    2016-12-13

    Dec 13, 2016 ... A 25‑year‑old air force personnel (lance corporal) presented to our accident and emergency ... Ocular Injuries: Another Example of the Heavy Prize of. Terrorism ..... Singapore: World Scientific Publishing Co. Pte. Ltd.; 2011. p.

  1. The cosmological singularity

    Belinski, Vladimir

    2018-01-01

    Written for researchers focusing on general relativity, supergravity, and cosmology, this is a self-contained exposition of the structure of the cosmological singularity in generic solutions of the Einstein equations, and an up-to-date mathematical derivation of the theory underlying the Belinski–Khalatnikov–Lifshitz (BKL) conjecture on this field. Part I provides a comprehensive review of the theory underlying the BKL conjecture. The generic asymptotic behavior near the cosmological singularity of the gravitational field, and fields describing other kinds of matter, is explained in detail. Part II focuses on the billiard reformulation of the BKL behavior. Taking a general approach, this section does not assume any simplifying symmetry conditions and applies to theories involving a range of matter fields and space-time dimensions, including supergravities. Overall, this book will equip theoretical and mathematical physicists with the theoretical fundamentals of the Big Bang, Big Crunch, Black Hole singula...

  2. Cosmological CP Violation

    Tomaschitz, R

    1994-01-01

    Spinor fields are studied in infinite, topologically multiply connected Robertson-Walker cosmologies. Unitary spinor representations for the discrete covering groups of the spacelike slices are constructed. The spectral resolution of Dirac's equation is given in terms of horospherical elementary waves, on which the treatment of spin and energy is based in these cosmologies. The meaning of the energy and the particle-antiparticle concept is explained in the context of this varying cosmic background. Discrete symmetries, in particular inversions of the multiply connected spacelike slices, are studied. The violation of the unitarity of the parity operator, due to self-interference of P-reflected wave packets, is discussed. The violation of the CP and CPT invariance - already on the level of the free Dirac equation on this cosmological background - is pointed out.

  3. Notes on Hadza cosmology

    Skaanes, Thea

    2015-01-01

    Abstract: This article concerns Hadza cosmology examined through objects, rituals and the Hadza concept of epeme. A brief background to the Hadza and the eldwork that informs this study is followed by a close analysis of three key objects that are central to the argument presented. The objects...... are intimately linked to women and to aspects of the social and cosmological identity of the individual makers. one object is a materi- alisation of the woman’s name and it leads to an examination by interview of naming practices more generally. Naming a child gives it a spirit and places the child in a strong...... of ethnographic research indicating the potential and need for further examination of the power and role of objects in Hadza society. Keywords: Hadza, epeme, ritual, cosmology, power objects...

  4. The philosophy of cosmology

    Silk, Joseph; Barrow, John D; Saunders, Simon

    2017-01-01

    Following a long-term international collaboration between leaders in cosmology and the philosophy of science, this volume addresses foundational questions at the limit of science across these disciplines, questions raised by observational and theoretical progress in modern cosmology. Space missions have mapped the Universe up to its early instants, opening up questions on what came before the Big Bang, the nature of space and time, and the quantum origin of the Universe. As the foundational volume of an emerging academic discipline, experts from relevant fields lay out the fundamental problems of contemporary cosmology and explore the routes toward finding possible solutions. Written for graduates and researchers in physics and philosophy, particular efforts are made to inform academics from other fields, as well as the educated public, who wish to understand our modern vision of the Universe, related philosophical questions, and the significant impacts on scientific methodology.

  5. 1990 Nobel Prize for the 'discovery' of quarks

    Taylor, G.N.

    1991-01-01

    The 1990 Nobel Prize in Physics has been awarded to Jerome I. Friedman, Henry W. Kendall and Richard E. Taylor for pioneering investigations of deep inelastic electron scattering off protons and neutrons, which played a crucial role in the development of quark model in particle physics. This paper is an attempt to present some background to the 1990 Nobel Prize and outlines the consequences of the experiments cited

  6. Cosmology and the early universe

    Di Bari, Pasquale

    2018-01-01

    This book discusses cosmology from both an observational and a strong theoretical perspective. The first part focuses on gravitation, notably the expansion of the universe and determination of cosmological parameters, before moving onto the main emphasis of the book, the physics of the early universe, and the connections between cosmological models and particle physics. Readers will gain a comprehensive account of cosmology and the latest observational results, without requiring prior knowledge of relativistic theories, making the text ideal for students.

  7. Non equilibrium relativistic cosmology

    Novello, M.; Salim, J.M.

    1982-01-01

    A certain systematization through the discussion of results already known on cosmology and the presentation of new ones is given. In section 2 a brief review of the necessary mathematical background is also given. The theory of perturbation of Friedmann-like Universes is presented in section 3. The reduction of Einstein's equations for homogeneous Universes to an autonomous planar system of differential equations is done in section 4. Finally in section 5 the alternative gravitational non-minimal coupling and its consequences to cosmology are discussed. (Author) [pt

  8. Cosmology without a beginning

    CERN. Geneva

    2000-01-01

    Most of the puzzles with standard big bang cosmology can be avoided if the big bang is NOT identified with the beginning of time. The short-distance cutoff and duality symmetries of superstring theory suggest a new (so-called pre-big bang) cosmology in which the birth of our Universe is the result of a long classical evolution characterized by a gravitational instability. I will motivate and describe this heretical scenario and compare its phenomenological implications with those of ortodox (post-big bang) inflation.

  9. Exploring Cosmology with Supernovae

    Li, Xue

    distribution of strong gravitational lensing is developed. For Type Ia supernova (SNe Ia), the rate is lower than core-collapse supernovae (CC SNe). The rate of SNe Ia declines beyond z 1:5. Based on these reasons, we investigate a potential candidate to measure cosmological distance: GRB......-SNe. They are a subclass of CC SNe. Light curves of GRB-SNe are obtained and their properties are studied. We ascertain that the properties of GRB-SNe make them another candidate for standardizable candles in measuring the cosmic distance. Cosmological parameters M and are constrained with the help of GRB-SNe. The first...

  10. Adventures in cosmology

    2012-01-01

    This volume tells of the quest for cosmology as seen by some of the finest cosmologists in the world. It starts with "Galaxy Formation from Start to Finish" and ends with "The First Supermassive Black Holes in the Universe," exploring in between the grand themes of galaxies, the early universe, expansion of the universe, dark matter and dark energy. This up-to-date collection of review articles offers a general introduction to cosmology and is intended for all probing into the profound questions on where we came from and where we are going.

  11. Horizons of cosmology

    Silk, Joseph

    2011-01-01

    Horizons of Cosmology: Exploring Worlds Seen and Unseen is the fourth title published in the Templeton Science and Religion Series, in which scientists from a wide range of fields distill their experience and knowledge into brief tours of their respective specialties. In this volume, highly esteemed astrophysicist Joseph Silk explores the vast mysteries and speculations of the field of cosmology in a way that balances an accessible style for the general reader and enough technical detail for advanced students and professionals. Indeed, while the p

  12. Relativistic Cosmology Revisited

    Crothers S. J.

    2007-04-01

    Full Text Available In a previous paper the writer treated of particular classes of cosmological solutions for certain Einstein spaces and claimed that no such solutions exist in relation thereto. In that paper the assumption that the proper radius is zero when the line-element is singular was generally applied. This general assumption is unjustified and must be dropped. Consequently, solutions do exist in relation to the aforementioned types, and are explored herein. The concept of the Big Bang cosmology is found to be inconsistent with General Relativity

  13. Cosmology and Dark Matter

    Tkachev, Igor

    2017-01-01

    This lecture course covers cosmology from the particle physicist perspective. Therefore, the emphasis will be on the evidence for the new physics in cosmological and astrophysical data together with minimal theoretical frameworks needed to understand and appreciate the evidence. I review the case for non-baryonic dark matter and describe popular models which incorporate it. In parallel, the story of dark energy will be developed, which includes accelerated expansion of the Universe today, the Universe origin in the Big Bang, and support for the Inflationary theory in CMBR data.

  14. Einstein and modern cosmology

    Stabell, R.

    1979-01-01

    Einstein applied his gravitation theory to a universe model with positively curved space in 1917. In order to maintain a static universe he introduced the cosmological constant, which in the light of later nonstatic universe models, he described as his life's greatest mistake. The best known such model is the Einstein-de Sitter model, which is here discussed in some detail. The 'big bang' theory is also discussed leading to the cosmic background radiation. The early phase of the 'big bang' cosmology, the first ten seconds, and the first minutes are discussed, leading to the transparent stage. (JIW)

  15. Cosmological models without singularities

    Petry, W.

    1981-01-01

    A previously studied theory of gravitation in flat space-time is applied to homogeneous and isotropic cosmological models. There exist two different classes of models without singularities: (i) ever-expanding models, (ii) oscillating models. The first class contains models with hot big bang. For these models there exist at the beginning of the universe-in contrast to Einstein's theory-very high but finite densities of matter and radiation with a big bang of very short duration. After short time these models pass into the homogeneous and isotropic models of Einstein's theory with spatial curvature equal to zero and cosmological constant ALPHA >= O. (author)

  16. Difficulties with inflationary cosmology

    Penrose, R.

    1989-01-01

    According to the author, the idea of inflationary cosmology is an ingenious attempt to solve some of the major puzzles of cosmology, most notably the flatness problem, the homogeneity (horizon) problem, and the monopole problem. The homogeneity problem, in particular, is intimately connected with a largely unappreciated, but profound puzzle presented by the second law of thermodynamics. The author argues that the mechanism of inflation does not, by itself, come to terms with this and consequently, comes nowhere close to providing an understanding of the large-scale homogeneity of the universe

  17. Fourth-rank cosmology

    Marrakchi, A.E.L.; Tapia, V.

    1992-05-01

    Some cosmological implications of the recently proposed fourth-rank theory of gravitation are studied. The model exhibits the possibility of being free from the horizon and flatness problems at the price of introducing a negative pressure. The field equations we obtain are compatible with k obs =0 and Ω obs t clas approx. 10 20 t Planck approx. 10 -23 s. When interpreted at the light of General Relativity the treatment is shown to be almost equivalent to that of the standard model of cosmology combined with the inflationary scenario. Hence, an interpretation of the negative pressure hypothesis is provided. (author). 8 refs

  18. Cosmological constants and variations

    Barrow, John D

    2005-01-01

    We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that is consistent with time-variation in the fine structure 'constant' since a redshift of 3.5. The behaviour of a simple class of varying alpha cosmologies is outlined in the light of all the observational constraints. We also discuss some of the consequences of varying 'constants' for oscillating universes and show by means of exact solutions that they appear to evolve monotonically in time even though the scale factor of the universe oscillates

  19. Polio and Nobel prizes: looking back 50 years.

    Norrby, Erling; Prusiner, Stanley B

    2007-05-01

    In 1954, John Enders, Thomas Weller, and Frederick Robbins were awarded the Nobel Prize in Physiology or Medicine "for their discovery of the ability of poliomyelitis viruses to grow in cultures of various types of tissue."5370 This discovery provided for the first time opportunities to produce both inactivated and live polio vaccines. By searching previously sealed Nobel Committee archives, we were able to review the deliberations that led to the award. It appears that Sven Gard, who was Professor of Virus Research at the Karolinska Institute and an adjunct member of the Nobel Committee at the time, played a major role in the events leading to the awarding of the Prize. It appears that Gard persuaded the College of Teachers at the Institute to decide not to follow the recommendation by their Nobel Committee to give the Prize to Vincent du Vigneaud. Another peculiar feature of the 1954 Prize is that Weller and Robbins were included based on only two nominations submitted for the first time that year. In his speech at the Nobel Prize ceremony, Gard mentioned the importance of the discovery for the future production of vaccines, but emphasized the implications of this work for growing many different, medically important viruses. We can only speculate on why later nominations highlighting the contributions of scientists such as Jonas Salk, Hilary Koprowski, and Albert Sabin in the development of poliovirus vaccines have not been recognized by a Nobel Prize.

  20. Alfred Nobel and His Prizes: From Dynamite to DNA.

    Lichtman, Marshall A

    2017-07-01

    Alfred Nobel was one of the most successful chemists, inventors, entrepreneurs, and businessmen of the late nineteenth century. In a decision later in life, he rewrote his will to leave virtually all his fortune to establish prizes for persons of any nationality who made the most compelling achievement for the benefit of mankind in the fields of chemistry, physics, physiology or medicine, literature, and peace among nations. The prizes were first awarded in 1901, five years after his death. In considering his choice of prizes, it may be pertinent that he used the principles of chemistry and physics in his inventions and he had a lifelong devotion to science, he suffered and died from severe coronary and cerebral atherosclerosis, and he was a bibliophile, an author, and mingled with the literati of Paris. His interest in harmony among nations may have derived from the effects of the applications of his inventions in warfare ("merchant of death") and his friendship with a leader in the movement to bring peace to nations of Europe. After some controversy, including Nobel's citizenship, the mechanisms to choose the laureates and make four of the awards were developed by a foundation established in Stockholm; the choice of the laureate for promoting harmony among nations was assigned to the Norwegian Storting, another controversy. The Nobel Prizes after 115 years remain the most prestigious of awards. This review describes the man, his foundation, and the prizes with a special commentary on the Nobel Prize in Physiology or Medicine.

  1. Conformal symmetry and holographic cosmology

    Bzowski, A.W.

    2013-01-01

    This thesis presents a novel approach to cosmology using gauge/gravity duality. Analysis of the implications of conformal invariance in field theories leads to quantitative cosmological predictions which are in agreement with current data. Furthermore, holographic cosmology extends the theory of

  2. Quintessence and the cosmological constant

    Doran, M.; Wetterich, C.

    2003-01-01

    Quintessence -- the energy density of a slowly evolving scalar field -- may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea in the light of the cosmological constant problem. Cosmological observations or a time variation of fundamental 'constants' can distinguish quintessence from a cosmological constant

  3. An X-prize for transport airships

    Hochstetler, R. [SAIC Canada, Ottawa, ON (Canada); Prentice, B.E. [Manitoba Univ., Winnipeg, MB (Canada). Transport Inst.

    2007-07-01

    Domestic air freight in the United States is expected to increase by at least 3 per cent every year for the next decade, while international demand will increase at twice that rate. As such, a new type of airship will be the most promising technological advance for the twenty-first century. Congestion in built up areas and demand for transport in remote areas has stimulated a resurgence of market interest in the potential value of lighter-than-air (LTA) vehicles for transport. Although most technical challenges have been addressed, the greatest challenge facing shippers is a lack of business confidence and policy directions to support investment in technology. Shippers are reluctant to commit the initial development funds needed to construct operational prototypes for testing. In 2004 and 2005, SAIC Canada conducted studies on airship technologies for the United States Army, and for use in the construction of oil and gas pipelines in remote regions. This paper presented a literature review of LTA technology as well as a brief market assessment. The criterion for an airship X-prize was then proposed as a challenge to stimulate the development of a transport airship capable of year round operations. It was concluded that transport airships offer a more benign system of transport that reduce greenhouse gases and provide a means of mitigating the damages done by existing transport services. 5 refs.

  4. Summary of cosmology workshop

    in quality, quantity, and the scope of cosmological observations. While the ob- ... In this article, I summarize both the oral and poster presentations made at the workshop. ... the angular spectrum of CMB anisotropy with recent measurements of the power spectrum of ..... A thermodynamical treatment within the framework of.

  5. Cosmological Parameters 2000

    Primack, Joel R.

    2000-01-01

    The cosmological parameters that I emphasize are the age of the universe $t_0$, the Hubble parameter $H_0 \\equiv 100 h$ km s$^{-1}$ Mpc$^{-1}$, the average matter density $\\Omega_m$, the baryonic matter density $\\Omega_b$, the neutrino density $\\Omega_\

  6. Culture and Children's Cosmology

    Siegal, Michael; Butterworth, George; Newcombe, Peter A.

    2004-01-01

    In this investigation, we examined children's knowledge of cosmology in relation to the shape of the earth and the day-night cycle. Using explicit questioning involving a choice of alternative answers and 3D models, we carried out a comparison of children aged 4-9 years living in Australia and England. Though Australia and England have a close…

  7. Cosmological dynamical systems

    Leon, Genly

    2011-01-01

    In this book are studied, from the perspective of the dynamical systems, several Universe models. In chapter 1 we give a bird's eye view on cosmology and cosmological problems. Chapter 2 is devoted to a brief review on some results and useful tools from the qualitative theory of dynamical systems. They provide the theoretical basis for the qualitative study of concrete cosmological models. Chapters 1 and 2 are a review of well-known results. Chapters 3, 4, 5 and 6 are devoted to our main results. In these chapters are extended and settled in a substantially different, more strict mathematical language, several results obtained by one of us in arXiv:0812.1013 [gr-qc]; arXiv:1009.0689 [gr-qc]; arXiv:0904.1577[gr-qc]; and arXiv:0909.3571 [hep-th]. In chapter 6, we provide a different approach to the subject discussed in astro-ph/0503478. Additionally, we perform a Poincar\\'e compactification process allowing to construct a global phase space containing all the cosmological information in both finite and infinite...

  8. Cosmology and unstable nuclei

    Schramm, D.N.

    1995-01-01

    Primordial nucleosynthesis has established itself as one of the three pillars of Big Bang cosmology. Many of the Big Bang Nucleosynthesis reactions involve unstable nuclei. Hence there is a tight relationship hetween the subject of this conference and cosmology. The prime role of unstable nuclei in cosmology is related to lithium synthesis and the lack of cosmological synthesis of Be and B. These nuclei will thus be focused upon. Nucleosynthesis involves comparing calculated abundances with observed abundances. In general, abundance determinations are dominated by systematic rather than statistical errors, and work on bounding systematics is crucial. The quark-hadron inspired inhomogeneous calculations now unanimously agree that only relatively small variations in Ω b are possible vis-a-vis the homogeneous model; hence the robustness of Ω b ∼0.05 is now apparent. (These calculations depend critically on unstable nuclei.) The above argues that the bulk of the baryons in the universe are not producing visible light. A comparison with the ROSAT cluster data is also shown to be consistent with the standard BBN model. Ω b ∼1 seems to be definitely excluded, so if Ω TOTAL =1, as some recent observations may hint, then non-baryonic dark matter is required. The implications of the recently reported halo microlensing events are discussed. In summary, it is argued that the physics of unstable nuclei affects the fundamental dark matter argument. ((orig.))

  9. Cosmology and the Bispectrum

    Sefusatti, Emiliano; /Fermilab /CCPP, New York; Crocce, Martin; Pueblas, Sebastian; Scoccimarro, Roman; /CCPP, New York

    2006-04-01

    The present spatial distribution of galaxies in the Universe is non-Gaussian, with 40% skewness in 50 h{sup -1} Mpc spheres, and remarkably little is known about the information encoded in it about cosmological parameters beyond the power spectrum. In this work they present an attempt to bridge this gap by studying the bispectrum, paying particular attention to a joint analysis with the power spectrum and their combination with CMB data. They address the covariance properties of the power spectrum and bispectrum including the effects of beat coupling that lead to interesting cross-correlations, and discuss how baryon acoustic oscillations break degeneracies. They show that the bispectrum has significant information on cosmological parameters well beyond its power in constraining galaxy bias, and when combined with the power spectrum is more complementary than combining power spectra of different samples of galaxies, since non-Gaussianity provides a somewhat different direction in parameter space. In the framework of flat cosmological models they show that most of the improvement of adding bispectrum information corresponds to parameters related to the amplitude and effective spectral index of perturbations, which can be improved by almost a factor of two. Moreover, they demonstrate that the expected statistical uncertainties in {sigma}s of a few percent are robust to relaxing the dark energy beyond a cosmological constant.

  10. Holography for cosmology

    McFadden, P.; Skenderis, K.

    2010-01-01

    We propose a holographic description of four-dimensional single-scalar inflationary universes, and show how cosmological observables, such as the primordial power spectrum, are encoded in the correlation functions of a three-dimensional quantum field theory (QFT). The holographic description

  11. Viscous causal cosmologies

    Novello, M.; Salim, J.M.; Torres, J.; Oliveira, H.P. de

    1989-01-01

    A set of spatially homogeneous and isotropic cosmological geometries generated by a class of non-perfect is investigated fluids. The irreversibility if this system is studied in the context of causal thermodynamics which provides a useful mechanism to conform to the non-violation of the causal principle. (author) [pt

  12. Solitons in relativistic cosmologies

    Pullin, J.

    1988-08-01

    The application to the construction of solitonic cosmologies in General Relativity of the Inverse Scattering Technique of Belinskii an Zakharov is analyzed. Three improvements to the mentioned technique are proposed: the inclusion of higher order poles in the scattering matrix, a new renormalization technique for diagonal metrics and the extension of the technique to include backgrounds with material content by means of a Kaluza-Klein formalism. As a consequence of these improvements, three new aspects can be analyzed: a) The construction of anisotropic and inhomogeneous cosmological models which can mimic the formation of halos and voids, due to the presence of a material content. The new renormalization technique allows to construct an exact perturbation theory. b) The analysis of the dynamics of models with cosmological constant (inflationary models) and their perturbations. c) The study of interaction of gravitational solitonic waves on material backgrounds. Moreover, some additional works, connected with the existance of 'Crack of doom' type singularities in Kaluza-Klein cosmologies, stochastic perturbations in inflationary universes and inflationary phase transitions in rotating universes are described. (Author) [es

  13. Tachyon field in cosmology

    This report is based on a recent work in collaboration with Bagla and Padmanabhan. [1]. In this paper, we construct cosmological models with homogeneous tachyon matter [2] to provide the dark energy component which drives acceleration of the universe (for a recent review of dark energy models, see [3]). We assume that.

  14. On the cosmological problem

    Heller, M.

    1986-01-01

    It is proposed to understand cosmology as a non-local physics. Non-local methods, when developed from locally performed observations, imply a considerable extrapolation, which in turn is possible without some unverifiable assumptions. Cosmology is, therefore, not only a science on the Universe but also about assumptions that render such a science possible. As far as theoretical aspects of cosmology are concerned, cosmology can be treated as a theory of the space of all solutions to Einstein's field equations (called the ensemble of universes). The very distinction is touched upon between solutions of differential equations, expressing laws of nature, and boundary conditions identifying particular instances of the law's operation. Both observational and theoretical studies demonstrate that our Universe occupies a distinguished position within the ensemble of universes. This fact remains in a close relationship with the existence and developing of structures in the Universe. Possible philosophies aimed at justifying or neutralizing our distinguished situation in the ensemble of universes are discussed at some length. 60 refs. (author)

  15. Ekpyrotic and cyclic cosmology

    Lehners, Jean-Luc

    2008-01-01

    Ekpyrotic and cyclic cosmologies provide theories of the very early and of the very late universe. In these models, the big bang is described as a collision of branes - and thus the big bang is not the beginning of time. Before the big bang, there is an ekpyrotic phase with equation of state w=P/(ρ) >>1 (where P is the average pressure and ρ the average energy density) during which the universe slowly contracts. This phase resolves the standard cosmological puzzles and generates a nearly scale-invariant spectrum of cosmological perturbations containing a significant non-Gaussian component. At the same time it produces small-amplitude gravitational waves with a blue spectrum. The dark energy dominating the present-day cosmological evolution is reinterpreted as a small attractive force between our brane and a parallel one. This force eventually induces a new ekpyrotic phase and a new brane collision, leading to the idea of a cyclic universe. This review discusses the detailed properties of these models, their embedding in M-theory and their viability, with an emphasis on open issues and observational signatures

  16. Cosmology solved? Maybe

    Turner, Michael S

    1999-03-01

    For two decades the hot big-bang model as been referred to as the standard cosmology - and for good reason. For just as long cosmologists have known that there are fundamental questions that are not answered by the standard cosmology and point to a grander theory. The best candidate for that grander theory is inflation + cold dark matter. It holds that the Universe is flat, that slowly moving elementary particles left over from the earliest moments provide the cosmic infrastructure, and that the primeval density inhomogeneities that seed all the structure arose from quantum fluctuations. There is now prima facie evidence that supports two basic tenets of this paradigm. An avalanche of high-quality cosmological observations will soon make this case stronger or will break it. Key questions remain to be answered; foremost among them are: identification and detection of the cold dark matter particles and elucidation of the dark-energy component. These are exciting times in cosmology{exclamation_point}.

  17. Excessive extrapolations in cosmology

    Křížek, Michal; Somer, L.

    2016-01-01

    Roč. 22, č. 3 (2016), s. 270-280 ISSN 0202-2893 Institutional support: RVO:67985840 Keywords : cosmology * friedmann equation Subject RIV: BA - General Mathematics Impact factor: 0.734, year: 2016 http://link.springer.com/article/10.1134%2FS0202289316030105

  18. Modified geodetic brane cosmology

    Cordero, Rubén; Cruz, Miguel; Molgado, Alberto; Rojas, Efraín

    2012-01-01

    We explore the cosmological implications provided by the geodetic brane gravity action corrected by an extrinsic curvature brane term, describing a codimension-1 brane embedded in a 5D fixed Minkowski spacetime. In the geodetic brane gravity action, we accommodate the correction term through a linear term in the extrinsic curvature swept out by the brane. We study the resulting geodetic-type equation of motion. Within a Friedmann–Robertson–Walker metric, we obtain a generalized Friedmann equation describing the associated cosmological evolution. We observe that, when the radiation-like energy contribution from the extra dimension is vanishing, this effective model leads to a self-(non-self)-accelerated expansion of the brane-like universe in dependence on the nature of the concomitant parameter β associated with the correction, which resembles an analogous behaviour in the DGP brane cosmology. Several possibilities in the description for the cosmic evolution of this model are embodied and characterized by the involved density parameters related in turn to the cosmological constant, the geometry characterizing the model, the introduced β parameter as well as the dark-like energy and the matter content on the brane. (paper)

  19. Supernova Cosmology Project

    , i.e. with the cosmology hidden. Looking Beyond Lambda with the Union Supernova Compilation by Rubin et Matrix Description Covariance Matrix with Systematics Description Full Table of All SNe Description Beyond Lambda Figures Updated 11-18-11 Contact: drubin at physics dot fsu dot edu, saul at lbl dot gov

  20. On Antimatter and Cosmology.

    Kevane, C J

    1961-02-24

    A cosmological model based on a gravitational plasma of matter and antimatter is discussed. The antigravitational interaction of matter and antimatter leads to segregation and an expansion of the plasma universe. The expansion time scale is controlled by the aggregation time scale.

  1. Projective relativity, cosmology and gravitation

    Arcidiacono, G.

    1986-01-01

    This book describes the latest applications of projective geometry to cosmology and gravitation. The contents of the book are; the Poincare group and Special Relativity, the thermodynamics and electromagnetism, general relativity, gravitation and cosmology, group theory and models of universe, the special projective relativity, the Fantappie group and Big-Bang cosmology, a new cosmological projective mechanics, the plasma physics and cosmology, the projective magnetohydrodynamics field, projective relativity and waves propagation, the generalizations of the gravitational field, the general projective relativity, the projective gravitational field, the De Sitter Universe and quantum physics, the conformal relativity and Newton gravitation

  2. Post-inflationary brane cosmology

    Mazumdar, Anupam

    2001-01-01

    The brane cosmology has invoked new challenges to the usual Big Bang cosmology. In this paper we present a brief account on thermal history of the post-inflationary brane cosmology. We have realized that it is not obvious that the post-inflationary brane cosmology would always deviate from the standard Big Bang cosmology. However, if it deviates some stringent conditions on the brane tension are to be satisfied. In this regard we study various implications on gravitino production and its abundance. We discuss Affleck-Dine mechanism for baryogenesis and make some comments on moduli and dilaton problems in this context

  3. Open problems in string cosmology

    Toumbas, N.

    2010-01-01

    Some of the open problems in string cosmology are highlighted within the context of the recently constructed thermal and quantum superstring cosmological solutions. Emphasis is given on the high temperature cosmological regime, where it is argued that thermal string vacua in the presence of gravito-magnetic fluxes can be used to bypass the Hagedorn instabilities of string gas cosmology. This article is based on a talk given at the workshop on ''Cosmology and Strings'', Corfu, September 6-13, 2009. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. Quantum cosmology - science of Genesis

    Padmanabhan, Thanu

    1987-01-01

    Quantum cosmology, the marriage between the theories of the microscopic and macroscopic Universe, is examined in an attempt to explain the birth of the Universe in the 'big bang'. A quantum cosmological model of the Universe does not exist, but a rough approximation, or 'poor man's' version of quantum cosmology has been developed. The idea is to combine the theory of quantum mechanics with the classical cosmological solutions to obtain a quantum mechanical version of cosmology. Such a model of quantum cosmology is described -here the quantum universe behaves like a hydrogen atom with the Planck length replacing the Bohr radius. Properties of quantum cosmologies and the significance of the Planck length are both discussed. (UK)

  5. Ecosystems Vulnerability Challenge and Prize Competition

    Smith, J. H.; Frame, M. T.; Ferriter, O.; Recker, J.

    2014-12-01

    Stimulating innovation and private sector entrepreneurship is an important way to advance the preparedness of communities, businesses and individuals for the impacts of climate change on certain aspects of ecosystems, such as: fire regimes; water availability; carbon sequestration; biodiversity conservation; weather-related hazards, and the spread of invasive species. The creation of tools is critical to help communities and natural resource managers better understand the impacts of climate change on ecosystems and the potential resulting implications for ecosystem services and conservation efforts. The Department of the Interior is leading an interagency effort to develop the Ecosystems Vulnerability theme as part of the President's Climate Action Plan. This effort will provide seamless access to relevant datasets that can help address such issues as: risk of wildfires to local communities and federal lands; water sensitivity to climate change; and understanding the role of ecosystems in a changing climate. This session will provide an overview of the proposed Ecosystem Vulnerability Challenge and Prize Competition, outlining the intended audience, scope, goals, and overall timeline. The session will provide an opportunity for participants to offer new ideas. Through the Challenge, access will be made available to critical datasets for software developers, engineers, scientists, students, and researchers to develop and submit applications addressing critical science issues facing our Nation today. Application submission criteria and guidelines will also be discussed. The Challenge will be open to all sectors and organizations (i.e. federal, non-federal, private sector, non-profits, and universities) within the United States. It is anticipated the Challenge will run from early January 2015 until spring of 2015.

  6. Pomeranchuk Prize awarded to André Martin

    Jordan Juras

    2010-01-01

    Professor André Martin has been awarded the I.Ya.Pomeranchuk Prize 2010, alongside Professor Valentine Zakharov.   André Martin, CERN theorist, pictured at the ceremony held in honour of his 80th birthday (August 2009). Established by the Institute of Theoretical and Experimental Physics (ITEP) in memory of an outstanding scientist Isaak Yakovlevich Pomeranchuk, the prize is awarded for the study of analytic properties of the scattering amplitude; which lead to the Froissart—Martin bound on the cross section growth with energy. The prize comes as a great honor for Martin, who was in fact a good friend of Mr. Pomeranchuk, "I am surprised and delighted to learn that I will be receiving the 2010 Pomeranchuk Prize. I was an admirer of Pomeranchuk and we shared a great friendship. I met with him for the last time in Erevan (Armenia) in 1965. As a good-bye, he told me, 'Analyticity exists'. This is precisely what I proved to earn the prize"....

  7. Cosmological Tests of Gravity

    CERN. Geneva

    2017-01-01

    Extensions of Einstein’s theory of General Relativity are under investigation as a potential explanation of the accelerating expansion rate of the universe. I’ll present a cosmologist’s overview of attempts to test these ideas in an efficient and unbiased manner. I’ll start by introducing the bestiary of alternative gravity theories that have been put forwards. This proliferation of models motivates us to develop model-independent, agnostic tools for comparing the theory space to cosmological data. I’ll introduce the effective field theory for cosmological perturbations, a framework designed to unify modified gravity theories in terms of a manageable set of parameters. Having outlined the formalism, I’ll talk about the current constraints on this framework, and the improvements expected from the next generation of large galaxy clustering, weak lensing and intensity mapping experiments.

  8. Towards a superstring cosmology

    Taylor, J.G.

    1987-01-01

    If superstring theory is a theory of everything then it must give a satisfactory description of the very early evolution of the universe. Since the very early universe is not directly observable, then by satisfactory it is mean that the later evolution following the earlier (pre-Planck time era) phase leads to agreement with prediction for the various observable phenomena such as (B-bar B), inflation, galaxy structure, the cosmological constant (infimum), etc. Moreover it is to be hoped that the initial singularity of classical general relativistic cosmology is also avoided. It is clear that superstring theory is not yet able to tackle these problems. This paper describes what has been done so far to construct very simplified versions of string theory relevant to the early universe, and discusses the critical questions still to be answered

  9. Nonlocal teleparallel cosmology.

    Bahamonde, Sebastian; Capozziello, Salvatore; Faizal, Mir; Nunes, Rafael C

    2017-01-01

    Even though it is not possible to differentiate general relativity from teleparallel gravity using classical experiments, it could be possible to discriminate between them by quantum gravitational effects. These effects have motivated the introduction of nonlocal deformations of general relativity, and similar effects are also expected to occur in teleparallel gravity. Here, we study nonlocal deformations of teleparallel gravity along with its cosmological solutions. We observe that nonlocal teleparallel gravity (like nonlocal general relativity) is consistent with the present cosmological data obtained by SNe Ia + BAO + CC + [Formula: see text] observations. Along this track, future experiments probing nonlocal effects could be used to test whether general relativity or teleparallel gravity gives the most consistent picture of gravitational interaction.

  10. Quantum cosmology: a review.

    Bojowald, Martin

    2015-02-01

    In quantum cosmology, one applies quantum physics to the whole universe. While no unique version and no completely well-defined theory is available yet, the framework gives rise to interesting conceptual, mathematical and physical questions. This review presents quantum cosmology in a new picture that tries to incorporate the importance of inhomogeneity. De-emphasizing the traditional minisuperspace view, the dynamics is rather formulated in terms of the interplay of many interacting 'microscopic' degrees of freedom that describe the space-time geometry. There is thus a close relationship with more-established systems in condensed-matter and particle physics even while the large set of space-time symmetries (general covariance) requires some adaptations and new developments. These extensions of standard methods are needed both at the fundamental level and at the stage of evaluating the theory by effective descriptions.

  11. Elementary particles and cosmology

    Audouze, J.; Paty, M.

    2000-01-01

    The universe is the most efficient laboratory of particle physics and the understanding of cosmological processes implies the knowledge of how elementary particles interact. This article recalls the mutual influences between on the one hand: astrophysics and cosmology and on the other hand: nuclear physics and particle physics. The big-bang theory relies on nuclear physics to explain the successive stages of nucleo-synthesis and the study of solar neutrinos has led to discover new aspects of this particle: it is likely that neutrinos undergo oscillations from one neutrino type to another. In some universe events such as the bursting of a super-nova, particles are released with a kinetic energy that would be impossible to reach on earth with a particle accelerator. These events are become common points of interest between astrophysicists and particle physicists and have promoted a deeper cooperation between astrophysics and elementary particle physics. (A.C.)

  12. Nonlocal teleparallel cosmology

    Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom); Capozziello, Salvatore [Universita di Napoli ' ' Federico II' ' , Dipartimento di Fisica ' ' E. Pancini' ' , Naples (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Compl. Univ. di Monte S. Angelo, Naples (Italy); INFN, Napoli (Italy); Faizal, Mir [University of British Columbia - Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Nunes, Rafael C. [Universidade Federal de Juiz de Fora, Departamento de Fisica, Juiz de Fora, MG (Brazil)

    2017-09-15

    Even though it is not possible to differentiate general relativity from teleparallel gravity using classical experiments, it could be possible to discriminate between them by quantum gravitational effects. These effects have motivated the introduction of nonlocal deformations of general relativity, and similar effects are also expected to occur in teleparallel gravity. Here, we study nonlocal deformations of teleparallel gravity along with its cosmological solutions. We observe that nonlocal teleparallel gravity (like nonlocal general relativity) is consistent with the present cosmological data obtained by SNe Ia + BAO + CC + H{sub 0} observations. Along this track, future experiments probing nonlocal effects could be used to test whether general relativity or teleparallel gravity gives the most consistent picture of gravitational interaction. (orig.)

  13. Supersymmetric GUTs and cosmology

    Lazarides, G.; Shafi, Q.

    1982-06-01

    By examining the behaviour of supersymmetric GUTs in the very early universe we find two classes of realistic models. In one of them supersymmetry is broken at or near the superheavy GUT scale. The cosmological implications of such models are expected to be similar to those of nonsupersymmetric GUTs. In the second class of models, the superheavy GUT scale is related to the supersymmetry breaking scale a la Witten. Two types of cosmological scenarios appear possible in this case, either with or without an intermediate (new) inflationary phase. They can be experimentally distinguished, since the former predicts an absence and the latter an observable number density of superheavy monopoles. A mechanism for generating baryon asymmetry in such models is pointed out. Further constraint on model building appears if global R invariance is employed to resolve the strong CP problem. (author)

  14. Quantum cosmology. 18

    Padmanabhan, T.

    1989-01-01

    Quantum cosmology is to quantum gravity what the Bohr model is to the full quantum mechanical description of the hydrogen atom. In quantum cosmology one attempts to give a quantum-mechanical meaning to classical solutions of general relativity. This is discussed in this chapter. The approach is illustrated by quantizing only the conformal degree of freedom of the gravitational field, in particular the Friedmann-Robertson-Walker models. And, as in the hydrogen atom, the classical singularity of general relativity is avoided and one has analogous stationary states in the quantum Universe. The chapter ends with a model of the fundamental role that the Planck length may play as the universal cutoff in all field theories, thus ridding the theory of ultra-violet divergences. Two appendices introduce field theory in the Schroedinger representation and the Schroedinger equation for quantum gravity, namely the Wheeler-De Wit equation. (author). 38 refs.; 2 figs.; 1 tab

  15. Massive neutrinos and cosmology

    Shandarin, S.F.

    1991-01-01

    This paper discussed the importance of the consequences of a nonzero neutrino rest mass on cosmology, perhaps, first recognized by Gershtein and Zeldovich, after the discover of the 3-K microwave background radiation MBR. Since the first works on the primordial synthesis of 4 He, it has been known that additional neutrino species increase the rate of expansion of the universe during the epoch of the primordial nucleosynthesis, which increases the yield of 4 He. Combining the results of the theory with astronomical measurements of the 4 He abundance and the estimate of the mass density of MBR, Shvartsman suggested the upper limit on the mass density of all relativistic matter at that epoch: ρ rel ≤ 5ρ MBR which eventually became the upper limit for the number of neutrino species: N ν ≤ 7. At that time, the constraints based on cosmological arguments were much stronger than one based on laboratory experiments

  16. Cosmology and convention

    Merritt, David

    2017-02-01

    I argue that some important elements of the current cosmological model are 'conventionalist' in the sense defined by Karl Popper. These elements include dark matter and dark energy; both are auxiliary hypotheses that were invoked in response to observations that falsified the standard model as it existed at the time. The use of conventionalist stratagems in response to unexpected observations implies that the field of cosmology is in a state of 'degenerating problemshift' in the language of Imre Lakatos. I show that the 'concordance' argument, often put forward by cosmologists in support of the current paradigm, is weaker than the convergence arguments that were made in the past in support of the atomic theory of matter or the quantization of energy.

  17. Cosmology, inflation, and supersymmetry

    Albrecht, A.; Dimopoulos, S.; Fischler, W.; Kolb, E.W.; Raby, S.; Steinhardt, P.J.

    1982-01-01

    Cosmological consequences of supersymmetric grand unified models based on the Witten-O'Raifeartaigh potential are discussed. In particular we study the development of the phase transition in the spontaneous breaking of supersymmetry. We find that in realistic models where light fields feel supersymmetry breaking only through coupling to massive fields, e.g., the Geometric Hierarchy model, the universe does not inflate or reheat. Thus, the standard cosmological flatness, monopole, and horizon problems remain. In addition, we find that the transition is never completed, in the sense that the universe remains dominated by coherent Higgs field energy, resulting in an apparent matter dominated universe with Ω greater than or equal to 10 30

  18. Nonlinear electrodynamics and cosmology

    Breton, Nora

    2010-01-01

    Nonlinear electrodynamics (NLED) generalizes Maxwell's theory for strong fields. When coupled to general relativity NLED presents interesting features like the non-vanishing of the trace of the energy-momentum tensor that leads to the possibility of violation of some energy conditions and of acting as a repulsive contribution in the Raychaudhuri equation. This theory is worth to study in cosmological and astrophysical situations characterized by strong electromagnetic and gravitational fields.

  19. Integrable scalar cosmologies

    Fré, P.; Sorin, A.S.; Trigiante, M.

    2014-01-01

    The question whether the integrable one-field cosmologies classified in a previous paper by Fré, Sagnotti and Sorin can be embedded as consistent one-field truncations into Extended Gauged Supergravity or in N=1 supergravity gauged by a superpotential without the use of D-terms is addressed in this paper. The answer is that such an embedding is very difficult and rare but not impossible. Indeed, we were able to find two examples of integrable models embedded in supergravity in this way. Both examples are fitted into N=1 supergravity by means of a very specific and interesting choice of the superpotential W(z). The question whether there are examples of such an embedding in Extended Gauged Supergravity remains open. In the present paper, relying on the embedding tensor formalism we classified all gaugings of the N=2 STU model, confirming, in the absence on hypermultiplets, the uniqueness of the stable de Sitter vacuum found several years ago by Fré, Trigiante and Van Proeyen and excluding the embedding of any integrable cosmological model. A detailed analysis of the space of exact solutions of the first supergravity-embedded integrable cosmological model revealed several new features worth an in-depth consideration. When the scalar potential has an extremum at a negative value, the Universe necessarily collapses into a Big Crunch notwithstanding its spatial flatness. The causal structure of these Universes is quite different from that of the closed, positive curved, Universe: indeed, in this case the particle and event horizons do not coincide and develop complicated patterns. The cosmological consequences of this unexpected mechanism deserve careful consideration

  20. Cosmology, Clusters and Calorimeters

    Figueroa-Feliciano, Enectali

    2005-01-01

    I will review the current state of Cosmology with Clusters and discuss the application of microcalorimeter arrays to this field. With the launch of Astro-E2 this summer and a slew of new missions being developed, microcalorimeters are the next big thing in x-ray astronomy. I will cover the basics and not-so-basic concepts of microcalorimeter designs and look at the future to see where this technology will go.

  1. Viscous Friedman cosmology

    Klimek, Z.

    1981-01-01

    The evolution of Friedman models with bulk viscosity in the plane ''Hubble's constant'' - energy density is presented. The general conclusions are: viscosity leads to intense energy production - energy density increases in spite of expansion; if the above result can be regarded as non-physical, the bulk viscosity can produce cosmological models without the initial singularity only for flat universes; the results do not essentially depend on the equation of state.

  2. Supersymmetric inflationary cosmology

    Ruiz-Altaba, M.

    1986-06-01

    An action is presented, within the framework of supergravity unification, which satisfies all experimental and cosmological constraints. In intermediate scale, around 10 10 - 10 11 GeV, arises from a critical examination of inflation, supersymmetry breaking, fermion masses, proton decay, baryogenesis, and electroweak breaking - including neutrino oscillations and CP violation. Careful consideration is given to some relevant calculations. 86 refs., 10 figs., 5 tabs

  3. Viscous Friedman cosmology

    Klimek, Z.

    1981-01-01

    The evolution of Friedman models with bulk viscosity in the plane ''Hubble's constant'' - energy density is presented. The general conclusions are: viscosity leads to intense energy production - energy density increases in spite of expansion; if the above result be regarded as non-physical, the bulk viscosity can produce cosmological models without the initial singularity only for flat universes; the results do not essentially depend on the equation of state. (author)

  4. Topics in inflationary cosmologies

    Mahajan, S.

    1986-04-01

    Several aspects of inflationary cosmologies are discussed. An introduction to the standard hot big bang cosmological model is reviewed, and some of the problems associated with it are presented. A short review of the proposals for solving the cosmological conundrums of the big bang model is presented. Old and the new inflationary scenarios are discussed and shown to be unacceptable. Some alternative scenarios especially those using supersymmetry are reviewed briefly. A study is given of inflationary models where the same set of fields that breaks supersymmetry is also responsible for inflation. In these models, the scale of supersymmetry breaking is related to the slope of the potential near the origin and can thus be kept low. It is found that a supersymmetry breaking scale of the order of the weak breaking scale. The cosmology obtained from the simplest of such models is discussed in detail and it is shown that there are no particular problems except a low reheating temperature and a violation of the thermal constraint. A possible solution to the thermal constraint problem is given by introducing a second field, and the role played by this second field in the scenario is discussed. An alternative mechanism for the generation of baryon number within the framework of supergravity inflationary models is studied using the gravitational couplings of the heavy fields with the hidden sector (the sector which breaks supersymmetry). This mechanism is applied to two specific models - one with and one without supersymmetry breaking. The baryon to entropy ratio is found to be dependent on parameters which are model dependent. Finally, the effect of direct coupling between the two sectors on results is related, 88 refs., 6 figs

  5. Vacuum inhomogeneous cosmological models

    Hanquin, J.-L.

    1984-01-01

    The author presents some results concerning the vacuum cosmological models which admit a 2-dimensional Abelian group of isometries: classifications of these space-times based on the topological nature of their space-like hypersurfaces and on their time evolution, analysis of the asymptotical behaviours at spatial infinity for hyperbolical models as well as in the neighbourhood of the singularity for the models possessing a time singularity during their evolution. (Auth.)

  6. Matter and cosmology

    Effenberger, R.

    1974-09-01

    The author summarizes some of the many questions and answers which have been raised over the years regarding the nature of matter, the origin of its forms and the associated concept of cosmology including the formation of the universe, our place in it and its course of evolution. An examination of the development of the classical concept of matter and its subsequent transformations within the space-time fields of relativity and quantum theory is also presented

  7. Is cosmology consistent?

    Wang Xiaomin; Tegmark, Max; Zaldarriaga, Matias

    2002-01-01

    We perform a detailed analysis of the latest cosmic microwave background (CMB) measurements (including BOOMERaNG, DASI, Maxima and CBI), both alone and jointly with other cosmological data sets involving, e.g., galaxy clustering and the Lyman Alpha Forest. We first address the question of whether the CMB data are internally consistent once calibration and beam uncertainties are taken into account, performing a series of statistical tests. With a few minor caveats, our answer is yes, and we compress all data into a single set of 24 bandpowers with associated covariance matrix and window functions. We then compute joint constraints on the 11 parameters of the 'standard' adiabatic inflationary cosmological model. Our best fit model passes a series of physical consistency checks and agrees with essentially all currently available cosmological data. In addition to sharp constraints on the cosmic matter budget in good agreement with those of the BOOMERaNG, DASI and Maxima teams, we obtain a heaviest neutrino mass range 0.04-4.2 eV and the sharpest constraints to date on gravity waves which (together with preference for a slight red-tilt) favor 'small-field' inflation models

  8. Cosmological phase transitions

    Kolb, E.W.

    1987-01-01

    If the universe stated from conditions of high temperature and density, there should have been a series of phase transitions associated with spontaneous symmetry breaking. The cosmological phase transitions could have observable consequences in the present Universe. Some of the consequences including the formation of topological defects and cosmological inflation are reviewed here. One of the most important tools in building particle physics models is the use of spontaneous symmetry breaking (SSB). The proposal that there are underlying symmetries of nature that are not manifest in the vacuum is a crucial link in the unification of forces. Of particular interest for cosmology is the expectation that are the high temperatures of the big bang symmetries broken today will be restored, and that there are phase transitions to the broken state. The possibility that topological defects will be produced in the transition is the subject of this section. The possibility that the Universe will undergo inflation in a phase transition will be the subject of the next section. Before discussing the creation of topological defects in the phase transition, some general aspects of high-temperature restoration of symmetry and the development of the phase transition will be reviewed. 29 references, 1 figure, 1 table

  9. Problems in quantum cosmology

    Amsterdamski, P.

    1986-01-01

    The standard cosmological model is reviewed and shown not to be self-sufficient in that it requires initial conditions most likely to be supplied by quantum cosmology. The possible approaches to the issue of initial conditions for cosmology are then discussed. In this thesis, the author considers three separate problems related to this issue. First, the possibility of inflation is investigated in detail by analyzing the evolution of metric perturbations and fluctuations in the expectation value of a scalar field prior to a phase transition; finite temperature effects are also included. Since the inhomogeneities were damped well before the onset of a phase transition. It is concluded that an inflation was possible. Next, the effective action of neutrino and photon fields is calculated for homogeneous spacetimes with small anisotropy; it is shown that quantum corrections to the action due to these fields influence the evolution of an early Universe in the Same way as do the analogous correction terms arising from a conformally invariant scalar which has been previously studied. Finally, the question of an early anisotropy is also discussed in a framework of Hartle-Hawking wave function of the Universe. A wave function of a Bianchi IX type Universe is calculated in a semiclassical approximation

  10. Course of cosmology

    Desert, F.-Xavier

    2004-01-01

    After an introduction comprising some definitions, an historical overview, and a discussion of the paradoxical Universe, this course proposes a presentation of fundamental notions and theories, i.e. the restrained relativity and the universal gravitation. The next part addresses the general relativity with the following notions: space-time metrics and principle of generalised covariance, basics of tensor analysis, geodesics, energy-pulse tensor, curvature, Einstein equations, Newtonian limit, Schwarzschild metrics, gravitational waves, gravitational redshift. The next part addresses the standard cosmology with the Friedmann-Robertson-Walker metrics and the Friedmann-Lemaitre equations of the evolution of the Universe. The Universe expansion is then addressed: distances and horizons, Hubble law, determination of the Hubble constant. The next chapter deals with the constituents of the Universe: light matter, baryonic dark matter, black matter, supernovae, Universe acceleration and black energy. Then comes the nuclear evolution of the Universe: thermodynamics of the primordial Universe, the matter-antimatter asymmetry, from quarks to atoms, cosmic abundance, neutron cosmological background, matter-radiation equality, cosmo-chronology or the age of the Universe. The next chapter addresses the cosmological background at 3 K: sky electromagnetic spectrum, measurement of CMB anisotropies, interpretation of anisotropies, growth of perturbations. The last chapter addresses the quantum field theory and inflation: paradoxes of the standard Big Bang, the simple inflation, noticeable consequences

  11. Quasars and cosmology

    Fliche, H.-H.; Souriau, J.-M.

    1978-03-01

    On the basis of colorimetric data a composite spectrum of quasars is established from the visible to the Lyman's limit. Its agreement with the spectrum of the quasar 3C273, obtained directly, confirms the homogeneity of these objects. The compatibility of the following hypotheses: negligible evolution of quasars, Friedmann type model of the universe with cosmological constant, is studied by means of two tests: a non-correlation test adopted to the observation conditions and the construction of diagrams (absolute magnitude, volume) using the K-correction deduced from the composite spectrum. This procedure happens to give relatively well-defined values of the parameters; the central values of the density parameter, the reduced curvature and the reduced cosmological constant are: Ω 0 =0.053, k 0 =0.245, lambda-zero=1.19, which correspond to a big bang model, eternally expanding, spatially finite, in which Hubble's parameter H is presently increasing. This model responds well to different cosmological tests: density of matter, diameter of radio sources, age of the universe. Its characteristics suggest various cosmogonic mechanisms, espacially mass formation by growth of empty spherical bubbles [fr

  12. Cosmology and astroparticles

    Gelmini, G.B.

    1996-01-01

    These lectures are devoted to elementary particle physicists and assume the reader has very little or no knowledge of cosmology and astrophysics. After a brief historical introduction to the development of modern cosmology and astro-particles in which the Hot Big Bang model is defined, the Robertson-Walker metric and the dynamics of the Friedmann-Robertson-Walker cosmology are discussed in section 2. In section 3 the main observational features of the Universe are reviewed, including a description of our neighborhood, homogeneity and isotropy, the cosmic background radiation, the expansion, the age and the matter content of the Universe. A brief account of the thermal history of the Universe follows in section 4, and relic abundances are discussed in section 5. Section 6 is devoted to primordial nucleosynthesis, section 7 to structure formation in the Universe and section 8 to the possibility of detection of the dark matter in the halo of our galaxy. In the relevant sections recent developments are included, such as several so called open-quote open-quote crisis close-quote close-quote (the age crisis, the cluster baryon crisis and the nucleosynthesis crisis), and the MACHO events that may constitute the first detection of dark matter in the halo of our galaxy. copyright 1996 American Institute of Physics

  13. Cosmology and astroparticles

    Gelmini, Graciela B.

    1996-01-01

    These lectures are devoted to elementary particle physicists and assume the reader has very little or no knowledge of cosmology and astrophysics. After a brief historical introduction to the development of modern cosmology and astro-particles in which the Hot Big Bang model is defined, the Robertson-Walker metric and the dynamics of the Friedmann-Robertson-Walker cosmology are discussed in section 2. In section 3 the main observational features of the Universe are reviewed, including a description of our neighborhood, homogeneity and isotropy, the cosmic background radiation, the expansion, the age and the matter content of the Universe. A brief account of the thermal history of the Universe follows in section 4, and relic abundances are discussed in section 5. Section 6 is devoted to primordial nucleosynthesis, section 7 to structure formation in the Universe and section 8 to the possibility of detection of the dark matter in the halo of our galaxy. In the relevant sections recent developments are included, such as several so called ''crisis'' (the age crisis, the cluster baryon crisis and the nucleosynthesis crisis), and the MACHO events that may constitute the first detection of dark matter in the halo of our galaxy

  14. Cosmological perturbations in antigravity

    Oltean, Marius; Brandenberger, Robert

    2014-10-01

    We compute the evolution of cosmological perturbations in a recently proposed Weyl-symmetric theory of two scalar fields with oppositely signed conformal couplings to Einstein gravity. It is motivated from the minimal conformal extension of the standard model, such that one of these scalar fields is the Higgs while the other is a new particle, the dilaton, introduced to make the Higgs mass conformally symmetric. At the background level, the theory admits novel geodesically complete cyclic cosmological solutions characterized by a brief period of repulsive gravity, or "antigravity," during each successive transition from a big crunch to a big bang. For simplicity, we consider scalar perturbations in the absence of anisotropies, with potential set to zero and without any radiation. We show that despite the necessarily wrong-signed kinetic term of the dilaton in the full action, these perturbations are neither ghostlike nor tachyonic in the limit of strongly repulsive gravity. On this basis, we argue—pending a future analysis of vector and tensor perturbations—that, with respect to perturbative stability, the cosmological solutions of this theory are viable.

  15. Cosmology from string theory

    Anchordoqui, Luis; Nawata, Satoshi; Goldberg, Haim; Nunez, Carlos

    2007-01-01

    We explore the cosmological content of Salam-Sezgin six-dimensional supergravity, and find a solution to the field equations in qualitative agreement with observation of distant supernovae, primordial nucleosynthesis abundances, and recent measurements of the cosmic microwave background. The carrier of the acceleration in the present de Sitter epoch is a quintessence field slowly rolling down its exponential potential. Intrinsic to this model is a second modulus which is automatically stabilized and acts as a source of cold dark matter, with a mass proportional to an exponential function of the quintessence field (hence realizing varying mass particle models within a string context). However, any attempt to saturate the present cold dark matter component in this manner leads to unacceptable deviations from cosmological data--a numerical study reveals that this source can account for up to about 7% of the total cold dark matter budget. We also show that (1) the model will support a de Sitter energy in agreement with observation at the expense of a miniscule breaking of supersymmetry in the compact space; (2) variations in the fine structure constant are controlled by the stabilized modulus and are negligible; (3) ''fifth'' forces are carried by the stabilized modulus and are short range; (4) the long time behavior of the model in four dimensions is that of a Robertson-Walker universe with a constant expansion rate (w=-1/3). Finally, we present a string theory background by lifting our six-dimensional cosmological solution to ten dimensions

  16. Inflation and quantum cosmology

    Linde, A.

    1990-01-01

    We investigate an interplay between elementary particle physics, quantum cosmology and inflation. These results obtained within this approach are compared with the results obtained in the context of Euclidean quantum cosmology. In particular, we discuss relations between the stochastic approach to inflationary cosmology and the approaches based on the investigation of the Hartle-Hawking and tunneling wave functions of the universe. We argue that neither of these wave functions can be used for a complete description of the inflationary universe, but in certain cases they can be used for a description of some particular stages of inflation. It is shown that if the present vacuum energy density ρ υ exceeds some extremely small critical value ρ c (ρ c ∼ 10 -107 ) g cm -3 for chaotic inflation in the theory 1/2m 2 φ 2 ), then the lifetime of mankind in the inflationary universe should be finite, even though the universe as a whole will exist without end. A possible way to justify the anthropic principle in the context of the baby universe theory and to apply it to the evaluation of masses of elementary particles, of their coupling constants and of the vacuum energy density is also discussed. (author)

  17. A varying-α brane world cosmology

    Youm, Donam

    2001-08-01

    We study the brane world cosmology in the RS2 model where the electric charge varies with time in the manner described by the varying fine-structure constant theory of Bekenstein. We map such varying electric charge cosmology to the dual variable-speed-of-light cosmology by changing system of units. We comment on cosmological implications for such cosmological models. (author)

  18. The Ripple Effect: Citation Chain Reactions of a Nobel Prize

    Faber Frandsen, Tove; Nicolaisen, Jeppe

    2013-01-01

    This paper explores the possible citation chain reactions of a Nobel Prize using the mathematician Robert J. Aumann as a case example. The results show that the award of the Nobel Prize in 2005 affected not only the citations to his work, but also affected the citations to the references in his s...... citation network. The effect is discussed using innovation decision process theory as a point of departure to identify the factors that created a bandwagon effect leading to the reported observations....... scientific oeuvre. The results indicate that the spillover effect is almost as powerful as the effect itself. We are consequently able to document a ripple effect in which the awarding of the Nobel Prize ignites a citation chain reaction to Aumann's scientific ouvre and to the references in its nearest...

  19. W K H Panofsky prize awarded for CP violation

    2006-01-01

    Italo Mannelli (left) et Heinrich Wahl (right) at CERN after the announcement of the prize. The American Physical Society has recently announced its 2007 winners of the W K H Panofsky prize to CERN's Heinrich Wahl (now at the University of Ferrara), Italo Mannelli from Scuola Normale Superiore di Pisa and Bruce Winstein of University of Chicago. These three physicists led experiments that resulted in a multitude of precision measurements of properties of neutral kaons, most notably the discovery of direct CP violation. The W K H Panofsky prize recognizes outstanding achievements in experimental particle physics. Wahl and Mannelli's important work at CERN with CP violation and neutral kaons in the 1970s paved the way for the NA31 experiment in the 1980s. This experiment, of which Wahl was the spokesperson, focused on and found the first evidence for direct CP violation. Mannelli played a leading role, particularly in implementing his knowledge of calorimetry using liquefied noble gases, a technique originally...

  20. The Meckel-Gruber syndrome protein TMEM67 controls basal body positioning and epithelial branching morphogenesis in mice via the non-canonical Wnt pathway

    Zakia A. Abdelhamed

    2015-06-01

    Full Text Available Ciliopathies are a group of developmental disorders that manifest with multi-organ anomalies. Mutations in TMEM67 (MKS3 cause a range of human ciliopathies, including Meckel-Gruber and Joubert syndromes. In this study we describe multi-organ developmental abnormalities in the Tmem67tm1Dgen/H1 knockout mouse that closely resemble those seen in Wnt5a and Ror2 knockout mice. These include pulmonary hypoplasia, ventricular septal defects, shortening of the body longitudinal axis, limb abnormalities, and cochlear hair cell stereociliary bundle orientation and basal body/kinocilium positioning defects. The basal body/kinocilium complex was often uncoupled from the hair bundle, suggesting aberrant basal body migration, although planar cell polarity and apical planar asymmetry in the organ of Corti were normal. TMEM67 (meckelin is essential for phosphorylation of the non-canonical Wnt receptor ROR2 (receptor-tyrosine-kinase-like orphan receptor 2 upon stimulation with Wnt5a-conditioned medium. ROR2 also colocalises and interacts with TMEM67 at the ciliary transition zone. Additionally, the extracellular N-terminal domain of TMEM67 preferentially binds to Wnt5a in an in vitro binding assay. Cultured lungs of Tmem67 mutant mice failed to respond to stimulation of epithelial branching morphogenesis by Wnt5a. Wnt5a also inhibited both the Shh and canonical Wnt/β-catenin signalling pathways in wild-type embryonic lung. Pulmonary hypoplasia phenotypes, including loss of correct epithelial branching morphogenesis and cell polarity, were rescued by stimulating the non-canonical Wnt pathway downstream of the Wnt5a-TMEM67-ROR2 axis by activating RhoA. We propose that TMEM67 is a receptor that has a main role in non-canonical Wnt signalling, mediated by Wnt5a and ROR2, and normally represses Shh signalling. Downstream therapeutic targeting of the Wnt5a-TMEM67-ROR2 axis might, therefore, reduce or prevent pulmonary hypoplasia in ciliopathies and other congenital

  1. Testing cosmology with galaxy clusters

    Rapetti Serra, David Angelo

    2011-01-01

    PASCOS 2011 will be held in Cambridge UK. The conference will be hosted by the Centre for Theoretical Cosmology (DAMTP) at the Mathematical Sciences site in the University of Cambridge. The aim of the conference is to explore and develop synergies between particle physics, string theory and cosmo......PASCOS 2011 will be held in Cambridge UK. The conference will be hosted by the Centre for Theoretical Cosmology (DAMTP) at the Mathematical Sciences site in the University of Cambridge. The aim of the conference is to explore and develop synergies between particle physics, string theory...... and cosmology. There will be an emphasis on timely interdisciplinary topics: • critical tests of inflationary cosmology • advances in fundamental cosmology • applications of string theory (AdS/CMT) • particle and string phenomenology • new experimental particle physics results • and cosmological probes...

  2. The Dirac-Milne cosmology

    Benoit-Lévy, Aurélien; Chardin, Gabriel

    2014-05-01

    We study an unconventional cosmology, in which we investigate the consequences that antigravity would pose to cosmology. We present the main characteristics of the Dirac-Milne Universe, a cosmological model where antimatter has a negative active gravitational mass. In this non-standard Universe, separate domains of matter and antimatter coexist at our epoch without annihilation, separated by a gravitationally induced depletion zone. We show that this cosmology does not require a priori the Dark Matter and Dark Energy components of the standard model of cosmology. Additionally, inflation becomes an unnecessary ingredient. Investigating this model, we show that the classical cosmological tests such as primordial nucleosynthesis, Type Ia supernovæ and Cosmic Microwave Background are surprisingly concordant.

  3. Particles and cosmology

    Tkachev, Igor

    1993-01-01

    When the common ground between particle physics, astrophysics and cosmology started to become a developing area, the Institute for Nuclear Research (INR) of the Russian Academy of Sciences had the foresight in 1981 to institute the Baksan Schools on Particles and Cosmology. This now traditional event, held biannually in the Baksan Valley, has gone on to attract international participation. The site is close to the INR Baksan Neutrino Observatory with its underground and surface installations, including the SAGE gallium solar neutrino detector, the Underground Scintillation Telescope, and the 'Carpet' extensive air shower array. Participation is mainly from experimentalists working in non accelerator particle physics and particle astrophysics. The most recent School, held from April 21 to 28, began with an opening address by INR Director V. A. Matveev. J.Frieman reviewed standard big bang cosmology, emphasizing how the recent COBE results and the observations of large scale galaxy clustering fit into a standard cosmology framework. For inflationary cosmology, he showed how different models may be tested through their predictions for large-scale galactic structure and for cosmic microwave background anisotropy. A.Stebbins presented details of the large scale distribution of galaxies which, combined with velocity information and microwave background anisotropy data, provide strong constraints on theories of the origin of primordial inhomogeneities. Inflation requires, and theories of the large scale structure strongly favour the critical value for the cosmic mass density, while, as D.Seckel explained in his lecture on nucleosynthesis and abundances of the light elements, the baryon contribution to this density has to be tens of times smaller. A general review on the observational evidence for dark matter, dark matter particle candidates and the strategy of dark matter searches was given by I. Tkachev, who stressed the gravitational microlensing MACHO

  4. Conformal Cosmology and Supernova Data

    Behnke, Danilo; Blaschke, David; Pervushin, Victor; Proskurin, Denis

    2000-01-01

    We define the cosmological parameters $H_{c,0}$, $\\Omega_{m,c}$ and $\\Omega_{\\Lambda, c}$ within the Conformal Cosmology as obtained by the homogeneous approximation to the conformal-invariant generalization of Einstein's General Relativity theory. We present the definitions of the age of the universe and of the luminosity distance in the context of this approach. A possible explanation of the recent data from distant supernovae Ia without a cosmological constant is presented.

  5. Cosmology for high energy physicists

    Albrecht, A.

    1987-11-01

    The standard big bang model of cosmology is presented. Although not perfect, its many successes make it a good starting point for most discussions of cosmology. Places are indicated where well understood laboratory physics is incorporated into the big bang, leading to successful predictions. Much less established aspects of high energy physics and some of the new ideas they have introduced into the field of cosmology are discussed, such as string theory, inflation and monopoles. 49 refs., 5 figs

  6. The world made by Noble prize : chemistry volume I

    2007-06-01

    This book contains two parts about items by chemistry. The first part introduces Alfred Bernhard Nodel, Pioneers without Nobel Prize, Garbage Bag, Non-sticky Frying Pan, Nylon Stockings, Plastic Electricity, Synthetic Dyestuff, Gin and Tonic, Soccer Ball, Fertilizer, DDT, Dentifrice, Kimchi, Makgeolli, Ice cream, Anodyne and Firefly. The second part lists PET-MRI, Color photo, Holography, Art diamond Incandescent lamp and Neon Sign, Imitation work, Alchemy, Nuclear Power plant, Synthetic Oil and Sugar, Freon gas, Water Car, Estate agency Mars, and winners of Nobel prize in physics.

  7. The world made by Noble prize : chemistry volume I

    NONE

    2007-06-15

    This book contains two parts about items by chemistry. The first part introduces Alfred Bernhard Nodel, Pioneers without Nobel Prize, Garbage Bag, Non-sticky Frying Pan, Nylon Stockings, Plastic Electricity, Synthetic Dyestuff, Gin and Tonic, Soccer Ball, Fertilizer, DDT, Dentifrice, Kimchi, Makgeolli, Ice cream, Anodyne and Firefly. The second part lists PET-MRI, Color photo, Holography, Art diamond Incandescent lamp and Neon Sign, Imitation work, Alchemy, Nuclear Power plant, Synthetic Oil and Sugar, Freon gas, Water Car, Estate agency Mars, and winners of Nobel prize in physics.

  8. The 2012 Nobel Prize in physics and David Wineland

    Mark, Um; Kihwan, Kim

    2013-01-01

    The 2012 Nobel prize in physics was awarded to David Wineland, together with Serge Haroche. David Wineland received the prize for ground-breaking experimental methods that enabled the measurement and manipulation of individual quantum systems, especially systems with trapped ions. He improved a trapped ion system and opened a new quantum world leading to quantum computation. He also realized optical atomic ion clocks with unprecedented precision through his experimental research. This article briefly reviews the history of trapped ion systems, the development of trapped-ion based quantum computation, and the development of the atomic ion clock, which are closely related to Wineland's achievements. (authors)

  9. 77 FR 58114 - SunShot Prize: Race to the Rooftop

    2012-09-19

    ...This notice announces the release of the SunShot Prize: Race to the Rooftop competition. This competition offers $10 million in prizes to those who can lower the non-hardware installation cost of rooftop solar energy systems.

  10. Perturbations in loop quantum cosmology

    Nelson, W; Agullo, I; Ashtekar, A

    2014-01-01

    The era of precision cosmology has allowed us to accurately determine many important cosmological parameters, in particular via the CMB. Confronting Loop Quantum Cosmology with these observations provides us with a powerful test of the theory. For this to be possible, we need a detailed understanding of the generation and evolution of inhomogeneous perturbations during the early, quantum gravity phase of the universe. Here, we have described how Loop Quantum Cosmology provides a completion of the inflationary paradigm, that is consistent with the observed power spectra of the CMB

  11. An introduction to modern cosmology

    Liddle, Andrew

    2015-01-01

    An Introduction to Modern Cosmology Third Edition is an accessible account of modern cosmological ideas. The Big Bang Cosmology is explored, looking at its observational successes in explaining the expansion of the Universe, the existence and properties of the cosmic microwave background, and the origin of light elements in the universe. Properties of the very early Universe are also covered, including the motivation for a rapid period of expansion known as cosmological inflation. The third edition brings this established undergraduate textbook up-to-date with the rapidly evolving observation

  12. Cosmological Reflection of Particle Symmetry

    Maxim Khlopov

    2016-08-01

    Full Text Available The standard model involves particle symmetry and the mechanism of its breaking. Modern cosmology is based on inflationary models with baryosynthesis and dark matter/energy, which involves physics beyond the standard model. Studies of the physical basis of modern cosmology combine direct searches for new physics at accelerators with its indirect non-accelerator probes, in which cosmological consequences of particle models play an important role. The cosmological reflection of particle symmetry and the mechanisms of its breaking are the subject of the present review.

  13. Posters of the 2013 Nobel Prize in Physics available from the Library

    CERN Library

    2014-01-01

    The Royal Swedish Academy of Sciences produces three posters annually, each of which explains the motivation for the award of the Nobel prizes in Physics, Chemistry and Economics.   The files of the posters are available here: http://www.kva.se/en/Prizes/Nobel-prizes/Nobel-Posters/ The good news is that the CERN Library has got a stock of posters of the 2013 Nobel Prize in Physics. They are available free from the Library (52-1-052).

  14. Students' participation in Hult Prize and their decision for entrepreneurship: Data gathered from Hult Prize 2018 regional finals in Nigeria.

    Oluwatobi, Stephen; Oshokoya, Damilare; Atayero, Aderemi; Oludayo, Olumuyiwa; Nsofor, Colette; Oyebode, Adeola

    2018-08-01

    This data article is an expression of data that reflects how students' participation in the Hult Prize 2018 regional finals affects their decision to become entrepreneurs. The primary data was sourced using a questionnaire developed with Google doc form. Out of 120 students that participated in the Hult Prize 2018 regional finals in Nigeria, 103 of them responded. Their responses are as presented in this article. Such will be relevant to researchers who want to find out why students desire to become entrepreneurs and the best approach and timing to enable them.

  15. 77 FR 36272 - SunShot Prize: America's Most Affordable Rooftop

    2012-06-18

    ...The Department of Energy (DOE) announces in this notice the release of the SunShot Prize: America's Most Affordable Rooftop Solar for public comment. Interested persons are encouraged to learn about the SunShot Prize: America's Most Affordable Rooftop rules at eere.energy.gov/solar/sunshot/prize.html.

  16. Recognizing mid-career productivity: the 2008 Retrovirology Prize, call for nomination

    Jeang Kuan-Teh

    2008-09-01

    Full Text Available Abstract A recent analysis suggested a narrow age range for productivity of innovative work by researchers. The Retrovirology Prize seeks to recognize the research of a mid-career retrovirologist between the ages of 45 and 60. The 2007 Retrovirology Prize was awarded to Dr. Karen Beemon. Nominations are being solicited for the 2008 prize.

  17. DOE-Supported Researcher Is Co-Winner of 2006 Nobel Prize in Physics

    DOE-Supported Researcher Is Co-Winner of 2006 Nobel Prize in Physics October 3, 2006 WASHINGTON, DC Space Flight Center for co-winning the 2006 Nobel Prize in Physics. "I offer my congratulations to with the 2006 Nobel Prize in Physics," Secretary Bodman said. "The groundbreaking work of

  18. Loop Quantum Cosmology.

    Bojowald, Martin

    2008-01-01

    Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical spacetime inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding spacetime is then modified. One particular theory is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. The main effects are introduced into effective classical equations, which allow one to avoid the interpretational problems of quantum theory. They give rise to new kinds of early-universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function, which allows an extension of quantum spacetime beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of spacetime arising in loop quantum gravity and its application to cosmology sheds light on more general issues, such as the nature of time. Supplementary material is available for this article at 10.12942/lrr-2008-4.

  19. Loop Quantum Cosmology

    Bojowald Martin

    2008-07-01

    Full Text Available Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical spacetime inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding spacetime is then modified. One particular theory is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. The main effects are introduced into effective classical equations, which allow one to avoid the interpretational problems of quantum theory. They give rise to new kinds of early-universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function, which allows an extension of quantum spacetime beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of spacetime arising in loop quantum gravity and its application to cosmology sheds light on more general issues, such as the nature of time.

  20. Loop Quantum Cosmology

    Bojowald Martin

    2005-12-01

    Full Text Available Quantum gravity is expected to be necessary in order to understand situations where classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical space-time inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding space-time is then modified. One particular realization is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. Main effects are introduced into effective classical equations which allow to avoid interpretational problems of quantum theory. They give rise to new kinds of early universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function which allows to extend space-time beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of space-time arising in loop quantum gravity and its application to cosmology sheds new light on more general issues such as time.

  1. Cosmology from quantum potential

    Farag Ali, Ahmed, E-mail: ahmed.ali@fsc.bu.edu.eg [Center for Fundamental Physics, Zewail City of Science and Technology, Giza, 12588 (Egypt); Dept. of Physics, Faculty of Sciences, Benha University, Benha, 13518 (Egypt); Das, Saurya, E-mail: saurya.das@uleth.c [Department of Physics and Astronomy, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4 (Canada)

    2015-02-04

    It was shown recently that replacing classical geodesics with quantal (Bohmian) trajectories gives rise to a quantum corrected Raychaudhuri equation (QRE). In this article we derive the second order Friedmann equations from the QRE, and show that this also contains a couple of quantum correction terms, the first of which can be interpreted as cosmological constant (and gives a correct estimate of its observed value), while the second as a radiation term in the early universe, which gets rid of the big-bang singularity and predicts an infinite age of our universe.

  2. Inflationary Axion Cosmology

    Wilczek, Frank; Turner, Michael S.

    1990-09-01

    If Peccei-Quinn (PQ) symmetry is broken after inflation, the initial axion angle is a random variable on cosmological scales; based on this fact, estimates of the relic-axion mass density give too large a value if the axion mass is less than about 10-6 eV. This bound can be evaded if the Universe underwent inflation after PQ symmetry breaking and if the observable Universe happens to be a region where the initial axion angle was atypically small, .1 . (ma/10-6eV)0.59. We show consideration of fluctuations induced during inflation severely constrains the latter alternative.

  3. Inflationary axion cosmology

    Turner, M.S.; Wilczek, F.

    1991-01-01

    If Peccei-Quinn (PQ) symmetry is broken after inflation, the initial axion angle is a random variable on cosmological scales; based on this fact, estimates of the relic-axion mass density give too large a value if the axion mass is less than about 10 -6 eV. This bound can be evaded if the Universe underwent inflation after PQ symmetry breaking and if the observable Universe happens to be a region where the initial axion angle was atypically small, θ 1 approx-lt[m a /10 -6 eV 0.59 .] We show consideration of fluctuations induced during inflation severely constrains the latter alternative

  4. Cosmology in antiquity

    Wright, Rosemary

    1995-01-01

    The popularity of Stephen Hawking's work has put cosmology back in the public eye. The question of how the universe began, and why it hangs together, still puzzles scientists. Their puzzlement began two and a half thousand years ago when Greek philosophers first 'looked up at the sky and formed a theory of everything.' Though their solutions are little credited today, the questions remain fresh.The early Greek thinkers struggled to come to terms with and explain the totality of their surroundings; to identitify an original substance from which the universe was compounded; and to reconcil

  5. Type Ia Supernova Cosmology

    Leibundgut, B.; Sullivan, M.

    2018-03-01

    The primary agent for Type Ia supernova cosmology is the uniformity of their appearance. We present the current status, achievements and uncertainties. The Hubble constant and the expansion history of the universe are key measurements provided by Type Ia supernovae. They were also instrumental in showing time dilation, which is a direct observational signature of expansion. Connections to explosion physics are made in the context of potential improvements of the quality of Type Ia supernovae as distance indicators. The coming years will see large efforts to use Type Ia supernovae to characterise dark energy.

  6. E10 cosmology

    Kleinschmidt, Axel; Nicolai, Hermann

    2006-01-01

    We construct simple exact solutions to the E 10 /K(E 10 ) coset model by exploiting its integrability. Using the known correspondences with the bosonic sectors of maximal supergravity theories, these exact solutions translate into exact cosmological solutions. In this way, we are able to recover some recently discovered solutions of M-theory exhibiting phases of accelerated expansion, or, equivalently, S-brane solutions, and thereby accommodate such solutions within the E 10 /K(E 10 ) model. We also discuss the situation regarding solutions with non-vanishing (constant) curvature of the internal manifold

  7. Quintessential brane cosmology

    Kunze, K.E.; Vazquez-Mozo, M.A.

    2002-01-01

    We study a class of braneworlds where the cosmological evolution arises as the result of the movement of a three-brane in a five-dimensional static dilatonic bulk, with and without reflection symmetry. The resulting four-dimensional Friedmann equation includes a term which, for a certain range of the parameters, effectively works as a quintessence component, producing an acceleration of the universe at late times. Using current observations and bounds derived from big-bang nucleosynthesis, we estimate the parameters that characterize the model

  8. Particle physics and cosmology

    Srednicki, M.

    1990-01-01

    At least eighty percent of the mass of the universe consists of some material which, unlike ordinary matter, neither emits nor absorbs light. This book collects key papers related to the discovery of this astonishing fact and its profound implications for astrophysics, cosmology, and the physics of elementary particles. The book focusses on the likely possibility that the dark matter is composed of an as yet undiscovered elementary particle, and examines the boundaries of our present knowledge of the properties such a particle must possess. (author). refs.; figs.; tabs

  9. Artemisinin: The journey from natural product to Nobel Prize ...

    The 2014 Nobel Prize for Physiology and Medicine was announced on 5th October. One-half ... The novel therapy that was given this huge recognition was artemisinin, a drug (isolated from the plant Artemisia annua) that has saved millions of lives and rekindled the dream of a world where malaria has been eradicated.

  10. Templeton Prize winner defends Christianity's credibility in a scientific age

    Heffern, Rich

    2002-01-01

    The 2002 Templeton Prize has gone to the Rev. John C. Polkinghome, a British mathematical physicist and Anglican priest, and a key spokesperson for belief in God in an age of science, defending the ideal that faith is not against science but inconcert with it

  11. The Nobel Prize winner in physics 2013--Peter Higgs

    Liu Jinyan

    2014-01-01

    Peter Higgs is a famous English physicist who was known for his works on Higgs mechanism and Higgs particle. He won the 2013 Noble Prize in physics. This paper briefly outlines his life, the proposition of Higgs mechanism and the origin of the name of Higgs particle. The discovery of Higgs particle is also given here. (author)

  12. Pennies from heaven? Conceptions and earmarking of lottery prize money.

    Hedenus, Anna

    2014-06-01

    The source of money has been shown to be important for how money is spent. In addition, sudden wealth is often associated with social and psychological risks. This article investigates if conceptions of lottery prize money--as a special kind of money--imply restrictions on how it can be spent. Analysis of interviews with lottery winners shows that interviewees use earmarking of the prize money as a strategy for avoiding the pitfalls associated with a lottery win. Conceptions of lottery prize money as 'a lot' or as 'a little', as shared or personal, and as an opportunity or a risk, influences the ends for which it is earmarked: for self-serving spending, a 'normal' living standard, paying off loans, saving for designated purposes, or for economic security and independence. Clearly defining and earmarking lottery prize money thus helps lottery winners construe their sudden wealth, not as a risk, but as 'pennies from heaven.' © London School of Economics and Political Science 2014.

  13. 2016 Nobel Prize in Chemistry: Conferring Molecular Machines as ...

    The Nobel Prize in Chemistry for the year 2016 was awardedto three illustrious chemists, Professors Jean-Pierre Sauvage,Sir Fraser Stoddart, and Ben Feringa. Pioneering works ofthese chemists on designing molecules, chemically synthesizingthem, and extracting a work out of such designedmoleculesopen-up a new ...

  14. The Progressive Insurance Automotive X PRIZE Education Program

    Robyn Ready

    2011-12-31

    The Progressive Insurance Automotive X PRIZE Education Program conducted education and outreach activities and used the competition's technical goals and vehicle demonstrations as a means of attracting students and the public to learn more about advanced vehicle technologies, energy efficiency, climate change, alternative fuels, and the science and math behind efficient vehicle development. The Progressive Insurance Automotive X PRIZE Education Program comprised three integrated components that were designed to educate the general public and create a multi-tiered initiative to engage students and showcase the 21st century skills students will need to compete in our global economy: teamwork, creativity, strong literacy, math and science skills, and innovative thinking. The elements included an Online Experience, a National Student Contest, and in person education events and activites. The project leveraged online connections, strategic partnerships, in-classroom, and beyond-the-classroom initiatives, as well as mainstream media. This education program supported by the U.S. Department of Energy (DOE) also funded the specification of vehicle telemetry and the full development and operation of an interactive online experience that allowed internet users to follow the Progressive Insurance Automotive X PRIZE vehicles as they performed in real-time during the Progressive Insurance Automotive X PRIZE competition events.

  15. 26 CFR 1.74-1 - Prizes and awards.

    2010-04-01

    ... Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.74-1 Prizes and awards. (a... goods or services, the fair market value of the goods or services is the amount to be included in income...

  16. Berners-Lee wins inaugural Millennium Technology prize

    2004-01-01

    "World Wide Web inventor Tim Berners-Lee today was named recipient of the first-ever Millennium Technology Prize. The honor, which is accompanied by one million euros, is bestowed by the Finnish Technology Award Foundation as an international acknowledgement of outstanding technological innovation aimed at promoting quality of life and sustainable economic and societal development" (1 page)

  17. Student Intern Lands Top Prize in National Science Competition | Poster

    By Ashley DeVine, Staff Writer Student intern Sam Pritt’s interest in improving geolocation led him to develop a project that won a top regional prize at the Siemens Competition in Math, Science, and Technology in November. Pritt was awarded a $3,000 college scholarship, and he competed in the national competition in early December.

  18. Neutron scattering and the 1994 Nobel Physics Prize

    Sun Xiangdong

    1995-01-01

    Neutron scattering is an efficient method for detecting the microstructure of matter by which we can study, for example, details of the phonon spectrum in solids, and the isotopic effect. Bertram N. Brockhouse and Clifford G. Shull earned the Nobel Physics Prize in 1994 for their significant contributions in this domain

  19. The 2013 Aspen Prize for Community College Excellence

    Perlstein, Linda

    2013-01-01

    For millions of Americans, community colleges provide an essential pathway to well-paying jobs and continuing higher education. The Aspen Prize for Community College Excellence honors those institutions that strive for and achieve exceptional levels of success for all students, while they are in college and after they graduate. Community colleges…

  20. Defining Excellence: Lessons from the 2013 Aspen Prize Finalists

    Aspen Institute, 2013

    2013-01-01

    In many respects, one couldn't find a group of 10 schools more diverse than the finalists for the 2013 Aspen Prize for Community College Excellence. One community college serves 1,500 students, another 56,000. There are institutions devoted primarily--even solely--to technical degrees, and ones devoted mainly to preparing students for further…

  1. Norman Ramsey. Nobel Prize Winner in Physics (1989)

    2003-01-01

    Norman Ramsey (Washington 1915) received the Nobel Prize in Physics (shared with con H. G. Dehmelt and W. Paul) for the development of study techniques for Atomic Physics. This tireless researcher participated in the discovery of the Magnetic Resonance Method for Molecular Emission. He invented the hydrogen maser and the hydrogen atomic clock, in addition to being a profile author. (Author)

  2. Lowy, Schiller win 2018 Szent-Györgyi Prize

    A press release announcing that NCI scientists Douglas R. Lowy and John T. Schiller will receive the 2018 Szent-Györgyi Prize for Progress in Cancer Research from the National Foundation for Cancer Research for their work on HPV vaccines.

  3. Harry Smith — recipient of the 2008 Molecular Ecology Prize

    Harry Smith is a scholar, mentor, internationally renowned researcher, eloquent speaker and author, pioneering journal editor and highly valued colleague who has contributed greatly in multiple ways to plant science and the community. He richly deserves the honour of the Molecular Ecology Prize....

  4. Tight Focus on Instruction Wins Texas District Prize

    Maxwell, Lesli A.

    2009-01-01

    It took a while for four-time finalist Aldine, Texas, to win the Broad Prize for Urban Education. But it took even longer to craft the system that ultimately put the district over the top. Educators in Aldine district have been working for more than a decade to refine their "managed instruction" system. Reviewers examined how the school…

  5. Cockcroft and Walton. Nobel Prize for Physics (1951)

    2003-01-01

    In 1951, the Nobel Prize for Physics was shared by researchers John Douglas Cockcroft (1897-1969) and Ernest Thomas Sinton Walton (1903-1995), for their pioneer work on the transmutation of the atomic nuclei by artificial acceleration of atomic particles. (Author)

  6. The Competition "First Step to Nobel Prize in Physics"

    Gorzkowski, W.; Surya, Y; Zuberek, R

    2011-01-01

    This paper presents the history of the competition First Step to Nobel Prize in Physics organized by Poland, its development from a national workshop in 1991/92 to an international competition nowadays and its organization, as well as the results obtained by the participants. (Contains 1 table.)

  7. The competition 'First Step to Nobel Prize in Physics'

    Gorzkowski, W; Zuberek, R; Surya, Y

    2011-01-01

    This paper presents the history of the competition First Step to Nobel Prize in Physics organized by Poland, its development from a national workshop in 1991/92 to an international competition nowadays and its organization, as well as the results obtained by the participants.

  8. Giving Back — IDRC photo contest winner shares prize with ...

    2011-01-28

    Jan 28, 2011 ... Giving Back — IDRC photo contest winner shares prize with Senegalese colleagues ... South or the developed world are tackling the challenges of urban living. ... Upon his return to Canada, the 26-year-old wrote to IDRC the ...

  9. SunShot Catalyst Prize Competition Fact Sheet

    Solar Energy Technologies Office

    2015-04-01

    This fact sheet is an overview of the Catalyst Energy Innovation Prize, an open innovation program launched in 2014 by the U.S. Department of Energy SunShot Initiative. This program aims to catalyze the rapid creation and development of products and solutions that address near-term challenges in the U.S. solar energy marketplace.

  10. 78 FR 40132 - Wave Energy Converter Prize Administration Webinar

    2013-07-03

    ... to submit comments electronically to ensure timely receipt. Minutes and video recorded proceedings of... low cost to the sponsoring agency. A successful challenge strategy is one that quickly yields a number... achievable performance threshold. It is intended that a WEC Prize could spur game changing innovations for...

  11. Supporting Military Veteran Students: Early Lessons from Kohlberg Prize Recipients

    Karp, Melinda Mechur; Klempin, Serena

    2016-01-01

    Postsecondary education participation is critical for military-connected individuals as they transition back to civilian life. The Kisco Foundation's Kohlberg Prize, a competitive grant awarded in 2015 and 2016, is aimed at making community colleges more welcoming and better able to meet the needs of veteran students. This review details the early…

  12. "Not Censorship but Selection": Censorship and/as Prizing

    Kidd, Kenneth

    2009-01-01

    This essay calls for a fresh critical approach to the topic of censorship, suggesting that anticensorship efforts, while important and necessary, function much like literary prizing. The analysis draws especially on James English's recent study "The Economy of Prestige." There are two central arguments: first, that the librarian ethic of…

  13. Training Quality: Before and after Winning the Deming Prize.

    Magennis, Jo P.

    1995-01-01

    Describes the Quality Improvement Program developed by Florida Power and Light's Nuclear Training organization that was awarded the Deming Application Prize for quality control. Training quality, team activities, training's role in business planning, customer involvement and evaluation, and continuous improvement of training are discussed. (LRW)

  14. The 2010 Chemistry Nobel Prize: Pd(0)-Catalyzed Organic Synthesis

    The 2010 Nobel Prize in Chemistry was awarded to three scientists, R F ... reactions are scalable to industrial production level and satisfy several 'Green ... Ph Br. H2C CH2. Pd(PPh3)4 or Pd(OAc2). HC CH2. Ph base, solvent, heat. 1. 2. 3. (1).

  15. E Pluribus Tres: The 2009 Nobel Prize in Chemistry

    Carter Jr., Charles W.

    2009-01-01

    This year’s Nobel Prize in Chemistry celebrates a multitude of research areas, making the difficult selection of those most responsible for providing atomic details of the nanomachine that makes proteins according to genetic instructions. The Ribosome and RNA polymerase (recognized in 2006) structures highlight a puzzling asymmetry at the origins of biology.

  16. The music of the Big Bang the cosmic microwave background and the new cosmology

    Balbi, Amedeo

    2008-01-01

    The cosmic microwave background radiation is the afterglow of the big bang: a tenuous signal, more than 13 billion years old, which carries the answers to many of the questions about the nature of our Universe. It was serendipitously discovered in 1964, and thoroughly investigated in the last four decades by a large number of experiments. Two Nobel Prizes in Physics have already been awarded for research on the cosmic background radiation: one in 1978 to Arno Penzias and Robert Wilson, who first discovered it, the other in 2006, to George Smoot and John Mather, for the results of the COBE satellite. Most cosmological information is encoded in the cosmic background radiation by acoustic oscillations in the dense plasma that filled the primordial Universe: a "music" of the big bang, which cosmologists have long been trying to reconstruct and analyze, in order to distinguish different cosmological models, much like one can distinguish different musical instruments by their timbre and overtones. Only lately, this...

  17. Cosmological effects of nonlinear electrodynamics

    Novello, M; Goulart, E; Salim, J M; Bergliaffa, S E Perez

    2007-01-01

    It will be shown that a given realization of nonlinear electrodynamics, used as a source of Einstein's equations, generates a cosmological model with interesting features, namely a phase of current cosmic acceleration, and the absence of an initial singularity, thus pointing to a way of solving two important problems in cosmology

  18. Quantum Gravity Effects in Cosmology

    Gu Je-An

    2018-01-01

    Full Text Available Within the geometrodynamic approach to quantum cosmology, we studied the quantum gravity effects in cosmology. The Gibbons-Hawking temperature is corrected by quantum gravity due to spacetime fluctuations and the power spectrum as well as any probe field will experience the effective temperature, a quantum gravity effect.

  19. Neutrino physics and precision cosmology

    Hannestad, Steen

    2016-01-01

    I review the current status of structure formation bounds on neutrino properties such as mass and energy density. I also discuss future cosmological bounds as well as a variety of different scenarios for reconciling cosmology with the presence of light sterile neutrinos....

  20. Modified General Relativity and Cosmology

    Abdel-Rahman, A.-M. M.

    1997-10-01

    Aspects of the modified general relativity theory of Rastall, Al-Rawaf and Taha are discussed in both the radiation- and matter-dominated flat cosmological models. A nucleosynthesis constraint on the theory's free parameter is obtained and the implication for the age of the Universe is discussed. The consistency of the modified matter- dominated model with the neoclassical cosmological tests is demonstrated.

  1. Vignettes in Gravitation and Cosmology

    Sriramkumar, L

    2012-01-01

    This book comprises expository articles on different aspects of gravitation and cosmology that are aimed at graduate students. The topics discussed are of contemporary interest assuming only an elementary introduction to gravitation and cosmology. The presentations are to a certain extent pedagogical in nature, and the material developed is not usually found in sufficient detail in recent textbooks in these areas.

  2. Kerr metric in cosmological background

    Vaidya, P C [Gujarat Univ., Ahmedabad (India). Dept. of Mathematics

    1977-06-01

    A metric satisfying Einstein's equation is given which in the vicinity of the source reduces to the well-known Kerr metric and which at large distances reduces to the Robertson-Walker metric of a nomogeneous cosmological model. The radius of the event horizon of the Kerr black hole in the cosmological background is found out.

  3. Introduction to gravity and cosmology

    Jauneau, L.

    1988-09-01

    Relativity principles, equivalence principles, and the general covariance principle are introduced. Curved space analysis via tensor calculus and absolute differential calculus is outlined. Einstein's equations are presented. The Schwarzschild solution; tests of general relativity; and black holes are discussed. Application of general relativity to cosmology is considered. The Standard Model of cosmology and its extensions are reviewed

  4. IAEA Nobel Peace Prize cancer and nutrition fund

    Kinley, D. III

    2006-05-01

    The Norwegian Nobel Committee awarded the 2005 Nobel Peace Prize to the IAEA and Director General ElBaradei in equal shares. The IAEA and its Director General won the 2005 Peace Prize for their efforts to prevent nuclear energy from being used for military purposes and to ensure that nuclear energy for peaceful purposes is used in the safest possible way. The IAEA Board of Governors subsequently decided that the IAEA's share of the prestigious prize would be used to create a special fund for fellowships and training to improve cancer control and childhood nutrition in the developing world. This fund is known as the 'IAEA Nobel Peace Prize Cancer and Nutrition Fund'. The money will be dedicated to enhancing human resources in developing regions of the world for improved cancer control and childhood nutrition. In the area of cancer control, the money will be spent on establishing regional cancer training institutes for the training of new doctors, medical physicists and technologists in radiation oncology to improve cancer treatment and care, as part of the IAEA's Programme of Action for Cancer Therapy (PACT). In the realm of nutrition, the focus of the Fund will be on capacity building in the use of nuclear techniques to develop interventions to contribute to improved nutrition and health for children in the developing world. Fund-supported fellowship awards will target young professionals, especially women, from Member States, through the IAEA's Technical Cooperation (TC) Programme. Alongside such awards, regional events will be organized in Africa, Asia and Latin America in cancer control and nutrition during 2006. The IAEA Secretariat is encouraging Member States and donors to contribute to the IAEA Nobel Peace Prize Cancer and Nutrition Fund by providing additional resources, in cash and in-kind

  5. Highlights in gravitation and cosmology

    Iyer, B.R.; Kembhavi, Ajit; Narlikar, J.V.; Vishveshwara, C.V.

    1988-01-01

    This book assesses research into gravitation and cosmology by examining the subject from various viewpoints: the classical and quantum pictures, along with the cosmological and astrophysical applications. There are 35 articles by experts of international standing. Each defines the state of the art and contains a concise summary of our present knowledge of a facet of gravitational physics. These edited papers are based on those first given at an international conference held in Goa, India at the end of 1987. The following broad areas are covered: classical relativity, quantum gravity, cosmology, black holes, compact objects, gravitational radiation and gravity experiments. In this volume there are also summaries of discussions on the following special topics: exact solutions of cosmological equations, mathematical aspects of general relativity, the early universe, and quantum gravity. For research workers in cosmology and gravitation this reference book provides a broad view of present achievements and current problems. (author)

  6. Is the cosmological singularity compulsory

    Bekenstein, J.D.; Meisels, A.

    1980-01-01

    The cosmological singularity is inherent in all conventional general relativistic cosmological models. There can be no question that it is an unphysical feature; yet there does not seem to be any convervative way of eliminating it. Here we present singularity-free isotropic cosmological models which are indistinguishable from general relativistic ones at late times. They are based on the general theory of variable rest masses that we developed recently. Outside cosmology this theory simulates general relativity well. Thus it provides a framework incorporating those features which have made geneal relativity so sucessful while providing a way out of singularity dilemma. The cosmological models can be made to incorporate Dirac's large numbers hypothesis. G(now)/G(0)approx.10 -38

  7. Higher dimensional loop quantum cosmology

    Zhang, Xiangdong

    2016-01-01

    Loop quantum cosmology (LQC) is the symmetric sector of loop quantum gravity. In this paper, we generalize the structure of loop quantum cosmology to the theories with arbitrary spacetime dimensions. The isotropic and homogeneous cosmological model in n + 1 dimensions is quantized by the loop quantization method. Interestingly, we find that the underlying quantum theories are divided into two qualitatively different sectors according to spacetime dimensions. The effective Hamiltonian and modified dynamical equations of n + 1 dimensional LQC are obtained. Moreover, our results indicate that the classical big bang singularity is resolved in arbitrary spacetime dimensions by a quantum bounce. We also briefly discuss the similarities and differences between the n + 1 dimensional model and the 3 + 1 dimensional one. Our model serves as a first example of higher dimensional loop quantum cosmology and offers the possibility to investigate quantum gravity effects in higher dimensional cosmology. (orig.)

  8. Towards a new cosmology

    Lachieze-Rey, Marc

    2005-01-01

    After having recalled that the Platonist and Aristotelian views were the basis of cosmology during the Antiquity and the Middle-Age, the author indicates that these views have been put into question again by Copernicus, Giordano Bruno, Kepler, Galileo and others whose works resulted in Newton physics. The author then follows and comments this history with the emergence of contemporary physics (relativistic and quantum physics) and new concepts for matter, space and time, light, energy, and the Universe with a relativistic cosmology. After having commented these last issues, the author evokes how new results confirmed big-bang models. He also outlines problems to be solved or addressed: observations related to the hidden mass, issue of unification, technological issues to obtain information about what went on more than 13 billions years ago. The author comments the issue of other universes, and issues regarding science, metaphysics and religion raised by these theoretical developments. He also comments the emergence of new physics (supersymmetry, quantum gravity)

  9. Topics in inflationary cosmology

    Kahn, R.N.

    1985-01-01

    This thesis examines several topics in the theory of inflationary cosmology. It first proves the existence of Hawking Radiation during the slow-rolling period of a new inflationary universe. It then derives and somewhat extends Bardeen's gauge invariant formalism for calculating the growth of linear gravitational perturbations in a Friedmann-Robertson-Walker cosmological background. This formalism is then applied, first to several new inflationary universe models all of which show a Zel'dovich spectrum of fluctuations, but with amplitude sigma(100 4 ) above observational limits. The general formalism is next applied to models that exhibit primordial inflation. Fluctuations in these models also exhibit a Zel'dovich spectrum here with an acceptable amplitude. Finally the thesis presents the results of new, numerical calculations. A classical, (2 + 1) dimensional computer model is developed that includes a Higgs field (which drives inflation) along with enough auxiliary fields to generate dynamically not only a thermal bath, but also the fluctuations that naturally accompany that bath. The thesis ends with a discussion of future prospects

  10. Cosmology with MATLAB

    Green, Dan

    2016-01-01

    This volume makes explicit use of the synergy between cosmology and high energy physics, for example, supersymmetry and dark matter, or nucleosynthesis and the baryon-to-photon ratio. In particular the exciting possible connection between the recently discovered Higgs scalar and the scalar field responsible for inflation is explored.The recent great advances in the accuracy of the basic cosmological parameters is exploited in that no free scale parameters such as h appear, rather the basic calculations are done numerically using all sources of energy density simultaneously. Scripts are provided that allow the reader to calculate exact results for the basic parameters. Throughout MATLAB tools such as symbolic math, numerical solutions, plots and 'movies' of the dynamical evolution of systems are used. The GUI package is also shown as an example of the real time manipulation of parameters which is available to the reader.All the MATLAB scripts are made available to the reader to explore examples of the uses of ...

  11. Indian cosmogonies and cosmologies

    Pajin Dušan

    2011-01-01

    Full Text Available Various ideas on how the universe appeared and develops, were in Indian tradition related to mythic, religious, or philosophical ideas and contexts, and developed during some 3.000 years - from the time of Vedas, to Puranas. Conserning its appeareance, two main ideas were presented. In one concept it appeared out of itself (auto-generated, and gods were among the first to appear in the cosmic sequences. In the other, it was a kind of divine creation, with hard work (like the dismembering of the primal Purusha, or as emanation of divine dance. Indian tradition had also various critiques of mythic and religious concepts (from the 8th c. BC, to the 6c., who favoured naturalistic and materialistic explanations, and concepts, in their cosmogony and cosmology. One the peculiarities was that indian cosmogony and cosmology includes great time spans, since they used a digit system which was later (in the 13th c. introduced to Europe by Fibonacci (Leonardo of Pisa, 1170-1240.

  12. Particle physics and cosmology

    Kolb, E.W.

    1986-10-01

    This series of lectures is about the role of particle physics in physical processes that occurred in the very early stages of the bug gang. Of particular interest is the role of particle physics in determining the evolution of the early Universe, and the effect of particle physics on the present structure of the Universe. The use of the big bang as a laboratory for placing limits on new particle physics theories will also be discussed. Section 1 reviews the standard cosmology, including primordial nucleosynthesis. Section 2 reviews the decoupling of weakly interacting particles in the early Universe, and discusses neutrino cosmology and the resulting limits that may be placed on the mass and lifetime of massive neutrinos. Section 3 discusses the evolution of the vacuum through phase transitions in the early Universe and the formation of topological defects in the transitions. Section 4 covers recent work on the generation of the baryon asymmetry by baryon-number violating reactions in Grand Unified Theories, and mentions some recent work on baryon number violation effects at the electroweak transition. Section 5 is devoted to theories of cosmic inflation. Finally, Section 6 is a discussion of the role of extra spatial dimensions in the evolution of the early Universe. 78 refs., 32 figs., 6 tabs

  13. Cosmology and Globalization

    Perkins, D. K.

    2006-08-01

    Microbes swarming on a sand grain planet or integral complex organisms evolving consciousness at the forefront of cosmic evolution? How is our new cosmology contributing to redefining who we see ourselves to be at the edge of the 21^st century, as globalization and capitalism speed forward? How is the evolution of stardust and the universe offering new paradigms of process and identity regarding the role, function and emergence of life in space-time? What are the cultural and philosophical questions that are arising and how might astronomy be contributing to the creation of new visions for cooperation and community at a global scale? What is the significance of including astronomy in K-12 education and what can it offer youth regarding values in light of the present world situation? Exploring our new cosmological concepts and the emergence of life at astronomical scales may offer much of valuable orientation toward reframing the human role in global evolution. Considering new insight from astrobiology each diverse species has a definitive role to play in the facilitation and functioning of the biosphere. Thus the question may arise: Is there any sort of ethic implied by natural science and offered by our rapidly expanding cosmic frontier?

  14. Cosmology and particle physics

    Salati, P.

    1986-01-01

    If the hot Big Bang model is correct, the very early universe provides us with a good laboratory to test our ideas on particle physics. The temperature and the density at that time are so high that each known particle must exist in chemical and in thermal equilibrium with the others. When the universe cools, the particles freeze out, leaving us today with a cosmic background. Such a kind of relic is of great interest because we can probe the Big Bang Model by studying the fossilized gas of a known particle. Conversely we can use that model to derive information about a hypothetical particle. Basically the freezing of a gas occurs a temperature T o and may be thermal or chemical. Studying the decoupling of a stable neutrino brings information on its mass: if the mass M ν lies in the forbidden range, the neutrino has to be unstable and its lifetime is constrained by cosmology. As for the G.U.T. Monopole, cosmology tells us that its present mass density is either to big or to small (1 monopole/observable universe) owing to a predicted flux far from the Parker Limit. Finally, the super red-giant star life time constrains the axion or the Higgs to be more massive than .2 MeV [fr

  15. Scalar cosmological perturbations

    Uggla, Claes; Wainwright, John

    2012-01-01

    Scalar perturbations of Friedmann-Lemaitre cosmologies can be analyzed in a variety of ways using Einstein's field equations, the Ricci and Bianchi identities, or the conservation equations for the stress-energy tensor, and possibly introducing a timelike reference congruence. The common ground is the use of gauge invariants derived from the metric tensor, the stress-energy tensor, or from vectors associated with a reference congruence, as basic variables. Although there is a complication in that there is no unique choice of gauge invariants, we will show that this can be used to advantage. With this in mind our first goal is to present an efficient way of constructing dimensionless gauge invariants associated with the tensors that are involved, and of determining their inter-relationships. Our second goal is to give a unified treatment of the various ways of writing the governing equations in dimensionless form using gauge-invariant variables, showing how simplicity can be achieved by a suitable choice of variables and normalization factors. Our third goal is to elucidate the connection between the metric-based approach and the so-called 1 + 3 gauge-invariant approach to cosmological perturbations. We restrict our considerations to linear perturbations, but our intent is to set the stage for the extension to second-order perturbations. (paper)

  16. Cosmology Without Finality

    Mahootian, F.

    2009-12-01

    The rapid convergence of advancing sensor technology, computational power, and knowledge discovery techniques over the past decade has brought unprecedented volumes of astronomical data together with unprecedented capabilities of data assimilation and analysis. A key result is that a new, data-driven "observational-inductive'' framework for scientific inquiry is taking shape and proving viable. The anticipated rise in data flow and processing power will have profound effects, e.g., confirmations and disconfirmations of existing theoretical claims both for and against the big bang model. But beyond enabling new discoveries can new data-driven frameworks of scientific inquiry reshape the epistemic ideals of science? The history of physics offers a comparison. The Bohr-Einstein debate over the "completeness'' of quantum mechanics centered on a question of ideals: what counts as science? We briefly examine lessons from that episode and pose questions about their applicability to cosmology. If the history of 20th century physics is any indication, the abandonment of absolutes (e.g., space, time, simultaneity, continuity, determinacy) can produce fundamental changes in understanding. The classical ideal of science, operative in both physics and cosmology, descends from the European Enlightenment. This ideal has for over 200 years guided science to seek the ultimate order of nature, to pursue the absolute theory, the "theory of everything.'' But now that we have new models of scientific inquiry powered by new technologies and driven more by data than by theory, it is time, finally, to relinquish dreams of a "final'' theory.

  17. Cosmology with decaying particles

    Turner, M.S.

    1984-09-01

    We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons β -1 identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (β) family of solutions; physically β -1 approx. = (Ω/sub R//Ω/sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references

  18. Cosmology with decaying particles

    Turner, M.S.

    1984-09-01

    We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons ..beta../sup -1/ identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (..beta..) family of solutions; physically ..beta../sup -1/ approx. = (..cap omega../sub R//..cap omega../sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references.

  19. Cosmology and philosophy

    Ginzburg, V.L.

    1981-01-01

    The problem of establishing boundaries between cosmology and philosophy is discussed. It is stated that the theoretic knowledge and observation data do not contradict the selection of one of non-stationary homogenous and isotropic relativistic models, which are also called the Friedmann models. In this model (with a zero Λ - member) there is a critical value of the substance density which is 10 -29 g/cm 2 . The determination of the average density of the Universe substance relatively to this value enables to choose between a closed and an open Universe model. Nowadays, this problem is not yet solved. But some philosophic theses reject the closed cosmological model without any naturally scientific argumentation. Critical remarks about such an approach to the problem studied are presented. The conclusion is made that the problems of the Universe volume infinity of finity, laws of its evolution in time or the like are not philosophic and should be considered taking into account the data of astronomic observations and modern physics

  20. Progress in quantum cosmology

    Hartle, J.B.

    1990-01-01

    Our observations of the world give us specific facts. Here, there is a galaxy; there is none. Today, there is a supernova explosion; yesterday, there was a star. Here, there are fission fragments; before, there was a uranium nucleus. The task of physics is to compress the message which describes these facts into a shorter form -to compress it, in particular, to a form where the message consists of just a few observed facts together with simple universal laws of nature from which the rest can be deduced. In the past, physics has concentrated on finding dynamical laws which correlate facts at different times. Such laws predict later evolution given observed initial conditions. However, there is no logical reason why we could not look for laws which correlate facts at the same time. Such laws would be, in effect, laws of initial conditions. It was the limited nature of our observations which led to our focus on dynamical laws. Now, however, in cosmology, in the observations of the early universe and even on familiar scales, it is possible to discern regularities of the world which may find a compressed expression in a simple, testable, theory of the initial conditions of the universe as a whole. The search for this law of the initial conditions is the subject of quantum cosmology and the subject whose recent development is reviewed. (author)

  1. Lord Rutherford of Nelson, his 1908 Nobel Prize in Chemistry, and why he didn't get a second prize

    Jarlskog, Cecilia

    2008-01-01

    'I have dealt with many different transformations with various periods of time, but the quickest that I have met was my own transformation in one moment from a physicist to a chemist.' Ernest Rutherford (Nobel Banquet, 1908) This article is about how Ernest Rutherford (1871-1937) got the 1908 Nobel Prize in Chemistry and why he did not get a second Prize for his subsequent outstanding discoveries in physics, specially the discovery of the atomic nucleus and the proton. Who were those who nominated him and who did he nominate for the Nobel Prizes? In order to put the Prize issue into its proper context, I will briefly describe Rutherford's whereabouts. Rutherford, an exceptionally gifted scientist who revolutionized chemistry and physics, was moulded in the finest classical tradition. What were his opinions on some scientific issues such as Einstein's photon, uncertainty relations and the future prospects for atomic energy? What would he have said about the 'Theory of Everything'? Extended version of an invited talk presented at the conference 'Neutrino 2008', Christchurch, NZ, 25-31 May 2008

  2. The cosmological perturbation theory in loop cosmology with holonomy corrections

    Wu, Jian-Pin; Ling, Yi

    2010-01-01

    In this paper we investigate the scalar mode of first-order metric perturbations over spatially flat FRW spacetime when the holonomy correction is taken into account in the semi-classical framework of loop quantum cosmology. By means of the Hamiltonian derivation, the cosmological perturbation equations is obtained in longitudinal gauge. It turns out that in the presence of metric perturbation the holonomy effects influence both background and perturbations, and contribute the non-trivial terms S h1 and S h2 in the cosmological perturbation equations

  3. Current Issues in Cosmology

    Barbour, J B [Department of Physics and Astronomy, University of Rochester (United States)

    2007-02-07

    These colloquium proceedings will be valuable, the blurb says, for graduate students and researchers in cosmology and theoretical astrophysics. Specifically, the book 'looks at both the strengths and weaknesses of the current big bang model in explaining certain puzzling data' and gives a 'comprehensive coverage of the expanding field of cosmology'. The reality is rather different. Conference proceedings rarely compare in value with a solid monograph or good review articles, and Current Issues in Cosmology is no exception. The colloquium was convened by the two editors, who have both long harboured doubts about the big bang, and was held in Paris in June 2004. The proceedings contain 19 presented papers and relatively brief summary comments by four panel speakers. The questions and answers at the end of each talk and a general discussion at the end were recorded and transcribed but contain little of interest. The nature of the colloquium is indicated by panellist Francesco Bertola's comment: 'While in the 1950s it was possible to speak of rival theories in cosmology, now the big-bang picture has no strong rivals. This is confirmed by the fact that out of 1500 members of the IAU Division VIII (Galaxies and the Universe) only a dozen, although bright people, devote their time to the heterodox views.' This was largely a platform for them to give their views. At least half of the dozen, all the 'usual suspects', were present: Geoffery and Margaret Burbidge, Jayant Narlikar, Halton Arp, Chandra Wickramasinghe and, in spirit only but playing a role somewhat like the ghost of Hamlet's father, the late Fred Hoyle. Doubters presented 12 of the 19 papers. Orthodoxy should certainly be challenged and the sociology of science questioned, but I found two main problems with this book. The papers putting the orthodox view are too short, even perfunctory. The most that a serious graduate student would get out of them is a reference

  4. Current Issues in Cosmology

    Barbour, J B

    2007-01-01

    These colloquium proceedings will be valuable, the blurb says, for graduate students and researchers in cosmology and theoretical astrophysics. Specifically, the book 'looks at both the strengths and weaknesses of the current big bang model in explaining certain puzzling data' and gives a 'comprehensive coverage of the expanding field of cosmology'. The reality is rather different. Conference proceedings rarely compare in value with a solid monograph or good review articles, and Current Issues in Cosmology is no exception. The colloquium was convened by the two editors, who have both long harboured doubts about the big bang, and was held in Paris in June 2004. The proceedings contain 19 presented papers and relatively brief summary comments by four panel speakers. The questions and answers at the end of each talk and a general discussion at the end were recorded and transcribed but contain little of interest. The nature of the colloquium is indicated by panellist Francesco Bertola's comment: 'While in the 1950s it was possible to speak of rival theories in cosmology, now the big-bang picture has no strong rivals. This is confirmed by the fact that out of 1500 members of the IAU Division VIII (Galaxies and the Universe) only a dozen, although bright people, devote their time to the heterodox views.' This was largely a platform for them to give their views. At least half of the dozen, all the 'usual suspects', were present: Geoffery and Margaret Burbidge, Jayant Narlikar, Halton Arp, Chandra Wickramasinghe and, in spirit only but playing a role somewhat like the ghost of Hamlet's father, the late Fred Hoyle. Doubters presented 12 of the 19 papers. Orthodoxy should certainly be challenged and the sociology of science questioned, but I found two main problems with this book. The papers putting the orthodox view are too short, even perfunctory. The most that a serious graduate student would get out of them is a reference to a far better review article or book on modern

  5. Scale-relativistic cosmology

    Nottale, Laurent

    2003-01-01

    The principle of relativity, when it is applied to scale transformations, leads to the suggestion of a generalization of fundamental dilations laws. These new special scale-relativistic resolution transformations involve log-Lorentz factors and lead to the occurrence of a minimal and of a maximal length-scale in nature, which are invariant under dilations. The minimal length-scale, that replaces the zero from the viewpoint of its physical properties, is identified with the Planck length l P , and the maximal scale, that replaces infinity, is identified with the cosmic scale L=Λ -1/2 , where Λ is the cosmological constant.The new interpretation of the Planck scale has several implications for the structure and history of the early Universe: we consider the questions of the origin, of the status of physical laws at very early times, of the horizon/causality problem and of fluctuations at recombination epoch.The new interpretation of the cosmic scale has consequences for our knowledge of the present universe, concerning in particular Mach's principle, the large number coincidence, the problem of the vacuum energy density, the nature and the value of the cosmological constant. The value (theoretically predicted ten years ago) of the scaled cosmological constant Ω Λ =0.75+/-0.15 is now supported by several different experiments (Hubble diagram of Supernovae, Boomerang measurements, gravitational lensing by clusters of galaxies).The scale-relativity framework also allows one to suggest a solution to the missing mass problem, and to make theoretical predictions of fundamental energy scales, thanks to the interpretation of new structures in scale space: fractal/classical transitions as Compton lengths, mass-coupling relations and critical value 4π 2 of inverse couplings. Among them, we find a structure at 3.27+/-0.26x10 20 eV, which agrees closely with the observed highest energy cosmic rays at 3.2+/-0.9x10 20 eV, and another at 5.3x10 -3 eV, which corresponds to the

  6. Inflationary cosmologies from compactification?

    Wohlfarth, Mattias N.R.

    2004-01-01

    We consider the compactification of (d+n)-dimensional pure gravity and of superstring or M-theory on an n-dimensional internal space to a d-dimensional Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmology, with a spatial curvature k=0,±1, in the Einstein conformal frame. The internal space is taken to be a product of Einstein spaces, each of which is allowed to have arbitrary curvature and a time-dependent volume. By investigating the effective d-dimensional scalar potential, which is a sum of exponentials, it is shown that such compactifications, in the k=0,+1 cases, do not lead to large amounts of accelerating expansion of the scale factor of the resulting FLRW universe, and, in particular, do not lead to inflation. The case k=-1 admits solutions with eternal accelerating expansion for which the acceleration, however, tends to zero at late times

  7. Cosmology for physicists

    Lyth, David

    2016-01-01

    Written by an award-winning cosmologist, this brand new textbook provides advanced undergraduate and graduate students with coverage of the very latest developments in the observational science of cosmology. The book is separated into three parts; part I covers particle physics and general relativity, part II explores an account of the known history of the universe, and part III studies inflation. Full treatment of the origin of structure, scalar fields, the cosmic microwave background and the early universe are provided. Problems are included in the book with solutions provided in a separate solutions manual. More advanced extension material is offered in the Appendix, ensuring the book is fully accessible to students with a wide variety of background experience.

  8. BMSSM implications for cosmology

    Bernal, Nicolas; Blum, Kfir; Nir, Yosef; Losada, Marta

    2009-01-01

    The addition of non-renormalizable terms involving the Higgs fields to the MSSM (BMSSM) ameliorates the little hierarchy problem of the MSSM. We analyze in detail the two main cosmological issues affected by the BMSSM: dark matter and baryogenesis. The regions for which the relic abundance of the LSP is consistent with WMAP and collider constraints are identified, showing that the bulk region and other previously excluded regions are now permitted. Requiring vacuum stability limits the allowed regions. Based on a two-loop finite temperature effective potential analysis, we show that the electroweak phase transition can be sufficiently first order in regions that for the MSSM are incompatible with the LEP Higgs mass bound, including parameter values of tan β∼ t -tilde 1 >m t , m Q < < TeV.

  9. Cosmological disformal invariance

    Domènech, Guillem; Sasaki, Misao [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Naruko, Atsushi, E-mail: guillem.domenech@yukawa.kyoto-u.ac.jp, E-mail: naruko@th.phys.titech.ac.jp, E-mail: misao@yukawa.kyoto-u.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2015-10-01

    The invariance of physical observables under disformal transformations is considered. It is known that conformal transformations leave physical observables invariant. However, whether it is true for disformal transformations is still an open question. In this paper, it is shown that a pure disformal transformation without any conformal factor is equivalent to rescaling the time coordinate. Since this rescaling applies equally to all the physical quantities, physics must be invariant under a disformal transformation, that is, neither causal structure, propagation speed nor any other property of the fields are affected by a disformal transformation itself. This fact is presented at the action level for gravitational and matter fields and it is illustrated with some examples of observable quantities. We also find the physical invariance for cosmological perturbations at linear and high orders in perturbation, extending previous studies. Finally, a comparison with Horndeski and beyond Horndeski theories under a disformal transformation is made.

  10. LHC, Astrophysics and Cosmology

    Giulio Auriemma

    2014-12-01

    Full Text Available In this paper we discuss the impact on cosmology of recent results obtained by the LHC (Large Hadron Collider experiments in the 2011-2012 runs, respectively at √s = 7 and 8 TeV. The capital achievement of LHC in this period has been the discovery of a spin-0 particle with mass 126 GeV/c2, very similar to the Higgs boson of the Standard Model of Particle Physics. Less exciting, but not less important, negative results of searches for Supersymmetric particles or other exotica in direct production or rare decays are discussed in connection with particles and V.H.E. astronomy searches for Dark Matter.

  11. Neutrinos in cosmology

    Tayler, R.J.

    1983-01-01

    The standard model of the hot big bang cosmological theory, which appears to be in agreement, at least qualitatively, with the observed properties of the Universe, assumes that the early Universe was homogeneous and isotropic and that it has been continuously expanding from a state characterized by very high temperature and density, where matter and radiation were to a good approximation in a state of thermodynamic equilibrium. In this standard model, it is assumed that baryon number, charge number and the various lepton numbers are all conserved. Only the baryon number is non-zero and this, expressed as the ratio of the net number of baryons (baryons minus antibaryons) to the number of photons per unit volume is the undefined parameter in the model. The author discusses the importance of knowing how many types of neutrinos there are with regard to the He 4 abundance, and the implication of a small, non-zero neutrino mass. (Auth.)

  12. Galaxy clusters and cosmology

    White, S

    1994-01-01

    Galaxy clusters are the largest coherent objects in Universe. It has been known since 1933 that their dynamical properties require either a modification of the theory of gravity, or the presence of a dominant component of unseen material of unknown nature. Clusters still provide the best laboratories for studying the amount and distribution of this dark matter relative to the material which can be observed directly -- the galaxies themselves and the hot,X-ray-emitting gas which lies between them.Imaging and spectroscopy of clusters by satellite-borne X -ray telescopes has greatly improved our knowledge of the structure and composition of this intergalactic medium. The results permit a number of new approaches to some fundamental cosmological questions,but current indications from the data are contradictory. The observed irregularity of real clusters seems to imply recent formation epochs which would require a universe with approximately the critical density. On the other hand, the large baryon fraction observ...

  13. Decoherence in quantum cosmology

    Halliwell, J.J.

    1989-01-01

    We discuss the manner in which the gravitational field becomes classical in quantum cosmology. This involves two steps. First, one must show that the quantum state of the gravitational field becomes strongly peaked about a set of classical configurations. Second, one must show that the system is in one of a number of states of a relatively permanent nature that have negligible interference with each other. This second step involves decoherence---destruction of the off-diagonal terms in the density matrix, representing interference. To introduce the notion of decoherence, we discuss it in the context of the quantum theory of measurement, following the environment-induced superselection approach of Zurek. We then go on to discuss the application of these ideas to quantum cosmology. We show, in a simple homogeneous isotropic model, that the density matrix of the Universe will decohere if the long-wavelength modes of an inhomogeneous massless scalar field are traced out. These modes effectively act as an environment which continuously ''monitors'' the scale factor. The coherence width is very small except in the neighborhood of a classical bounce. This means that one cannot really say that a classical solution bounces because the notion of classical spacetime does not apply. The coherence width decreases as the scale factor increases, which has implications for the arrow of time. We also show, using decoherence arguments, that the WKB component of the wave function of the Universe which represents expanding universes has negligible interference with the collapsing component. This justifies the usual assumption that they may be treated separately

  14. Cosmological and supernova neutrinos

    Kajino, T.; Aoki, W.; Balantekin, A. B.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Kusakabe, M.; Mathews, G. J.; Nakamura, K.; Pehlivan, Y.; Shibagaki, S.; Suzuki, T.

    2014-06-01

    The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial 7Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and 7Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like 7Li, 11B, 92Nb, 138La and 180Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ13 with predicted and observed supernova-produced abundance ratio 11B/7Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

  15. Cosmological and supernova neutrinos

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Balantekin, A. B. [Department of Physics, University of Wisconsin - Madison, Wisconsin 53706 (United States); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Kusakabe, M. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Mathews, G. J. [Department of Physics, University of Notre Dame, IN 46556 (United States); Nakamura, K. [Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Pehlivan, Y. [Mimar Sinan GSÜ, Department of Physics, Şişli, İstanbul 34380 (Turkey); Suzuki, T. [Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-06-24

    The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial {sup 7}Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and {sup 7}Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ{sub 13} with predicted and observed supernova-produced abundance ratio {sup 11}B/{sup 7}Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

  16. 2014 Nuclear Fusion Prize Acceptance Speech 2014 Nuclear Fusion Prize Acceptance Speech

    Snyder, P. B.

    2015-01-01

    It is a great honor to receive the 2014 Nuclear Fusion Prize, here at the 25th IAEA Fusion Energy Conference. On behalf of everyone involved in this work, I would like to thank the IAEA, the Nuclear Fusion journal team, the IOP, and specifically Mitsuru Kikuchi, for their support of this important award. I would also like to acknowledge the many important contributions made by the other ten papers nominated for this prize. Our paper investigates the physics of the H-mode pedestal in tokamaks, specifically the development of a predictive understanding of the pedestal structure based on electromagnetic instabilities which constrain it, and the testing of the resulting theoretical model (EPED) against detailed observations on multiple devices. In addition to making pedestal predictions for existing devices, the paper also presents predictions for ITER, including methods for optimizing its pedestal height and fusion performance. What made this work possible, and indeed a pleasure to be involved with, was an extensive set of collaborations, including theory-experiment, multi-institutional, and international collaborations. Many of these collaborations have gone on for over a decade, and have been fostered in part by the ITPA Pedestal Group. The eight authors of this paper, from five institutions, all made important contributions. Rich Groebner, Tom Osborne and Tony Leonard carried out dedicated experiments and data analysis on the DIII-D tokamak, testing the EPED model over a very wide range of parameters. Jerry Hughes led dedicated experiments on Alcator C-Mod which tested the model at high magnetic field and pedestal pressure. Marc Beurskens carried out experiments and data analysis on the JET tokamak, testing the model at large scale. Xueqiao Xu conducted two-fluid studies of diamagnetic stabilization, which enabled a more accurate treatment of this important effect. Finally, Howard Wilson and I have been working together for many years to develop analytic formalism

  17. Cosmology and the weak interaction

    Schramm, D.N. (Fermi National Accelerator Lab., Batavia, IL (USA)):(Chicago Univ., IL (USA))

    1989-12-01

    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.

  18. Cosmology and the weak interaction

    Schramm, D.N.

    1989-12-01

    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N ν ∼ 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs

  19. A new cosmological paradigm: the cosmological constant and dark matter

    Krauss, L.M.

    1998-01-01

    The Standard Cosmological Model of the 1980 close-quote s is no more. I describe the definitive evidence that the density of matter is insufficient to result in a flat universe, as well as the mounting evidence that the cosmological constant is not zero. I finally discuss the implications of these results for particle physics and direct searches for non-baryonic dark matter. copyright 1998 American Institute of Physics

  20. The cosmological term and a modified Brans-Dicke cosmology

    Endo, M.; Fukui, T.

    1977-01-01

    Adding the cosmological term Λ, which is assumed to be variable in this paper, to the Brans-Dicke Lagrangian, an attempt is made to understand the meaning of the term and to relate it to the mass of the universe. The Dirac large-number hypothesis is considered, applying the results obtained from the application of the present theory to a uniform cosmological model. (author)

  1. Cosmological applications in Kaluza—Klein theory

    Wanas, M.I.; Nashed, Gamal G. L.; Nowaya, A.A.

    2012-01-01

    The field equations of Kaluza—Klein (KK) theory have been applied in the domain of cosmology. These equations are solved for a flat universe by taking the gravitational and the cosmological constants as a function of time t. We use Taylor's expansion of cosmological function, Λ(t), up to the first order of the time t. The cosmological parameters are calculated and some cosmological problems are discussed. (geophysics, astronomy, and astrophysics)

  2. Pierre Darriulat is awarded the André Lagarrigue Prize

    2009-01-01

    Pierre Darriulat at the VATLY Laboratory in Hanoï. Former CERN Research Director, Pierre Darriulat, who is now Professor of Physics at VATLY in Hanoi (Vietnam), has won the 2008 André Lagarrigue Prize. This prize, instituted by the Linear Accelerator Laboratory (LAL) at Orsay under the aegis of the French Physical Society, is awarded to front-line researchers who have had responsibility for machine/detector construction and derived maximum scientific benefit from such projects, performed in a French laboratory or in close collaboration with French groups. Pierre Darriulat has received the award in recognition of his outstanding career at the CEA, at LBL (Berkeley) and at CERN from 1964 onwards. At CERN he managed the experiments at the Intersecting Storage Rings (ISR) before taking charge of the UA2 collaboration from 1980 to 1986, which participated in decisive discoveries at the ppbar collider. In particular, in 1982, the UA2 experiment began observing high trans...

  3. Tim Berners-Lee receives the Millennium Technology Prize

    2004-01-01

    On 15 April, for his invention of the Web, Tim Berners-Lee was awarded the first ever Millennium Technology Prize by the Finnish Technology Award Foundation, which recognises technological innovations of lasting benefit to society. "Tim Berners-Lee's invention perfectly encapsulates the spirit of the Prize. The Web is encouraging new types of social networks, contributing to transparency and democracy, and opening up new avenues for information management and business development," underlined Pekka Tarjanne, chairman of the jury and former Secretary-General of the International Telecommunication Union (ITU). Tim Berners-Lee is congratulated by Jukka Valtasaari, Finland's Ambassador to the United States. Tim Berners-Lee created the first server, browser and editor, the HTML code, the URL address and the HTTP transmission protocol at CERN in 1990. CERN released the Web into the public domain in 1993. Tim Berners-Lee is currently head of the World Wide Web Consortium, managed by ERCIM (Europe...

  4. Nobel Prize winner visits CERN’s superconductors

    2008-01-01

    On Wednesday 23 April Georg Bednorz, who won the Nobel Prize for physics in 1987, visited CERN along with 44 of his colleagues from the IBM Zurich Research Laboratory. Georg Bednorz (second from right) with colleagues from the IBM Zurich Research Laboratory in the LHC tunnel. On their arrival, Jos Engelen, the Chief Scientific Officer, gave the IBM group an introduction to CERN. Bednorz came to CERN only recently for the Open Days to give a seminar, but unfortunately did not have time to visit the experiments, so this trip was organised instead. Along with Alex Müller, Bednorz was awarded the Noble Prize for his discovery of superconductivity for the so-called high temperature superconductors, essentially copper-oxide-based compounds showing superconductivity at temperatures much higher than had previously been thought possible. The LHC magnets are built with low-temperature superconductors but many current leads that supply power to the LHC cryostats are made with...

  5. 'Exhibitions and experiments', in celebration of nobel prize in physics

    Hayashi, Masahito; Nakanishi, Akira; Nakano, Masahiro

    2010-01-01

    The Nobel Prize in Physics for 2008 was awarded to Professors Yoichiro Nambu, Makoto Kobayashi and Toshihide Maskawa. At this opportunity, we held an exhibition to introduce the achievements of the laureates for 10 days at the Omiya campus in May 2009. With the explanations of elementary particle physics, we prepared several experimental instruments with which visitors could play and learn the spontaneous symmetry breaking, cosmic rays, a circle path of an electron in a magnetic field and so on. Our main purpose of the exhibition was, however, not just to explain the contents of the Nobel Prize in Physics, but also to attract students' interests to physics. More than 800 individual students attended during the period, and the survey of questionnaires shows positive contributions to raise the students' awareness of the excitement of physics. (author)

  6. Alert with destruction of stratospheric ozone: 95 Nobel Prize Winners

    Santamaria, J.; Zurita, E.

    1995-01-01

    After briefly summarizing the discoveries of the 95 Nobel Prize Winners in Chemistry related to the threats to the ozone layer by chemical pollutants, we make a soft presentation of the overall problem of stratospheric ozone, starting with the destructive catalytic cycles of the pollutant-based free radicals, following with the diffusion mathematical models in Atmospheric Chemistry, and ending with the increasing annual drama of the ozone hole in the Antarctica. (Author)

  7. Marcus wins nobel prize in chemistry for electron transfer theory

    Levi, B.G.

    1993-01-01

    This article describes the work of Rudolf Marcus of Caltech leading to his receipt of the 1992 Nobel Prize in Chemistry open-quotes for his contributions to the theory of electron transfer reactions in chemical systems.close quotes Applications of Marcus' theory include such diverse phenomena as photosynthesis, electrically conducting polymers, chemiluminescence, and corrosion. Historical aspects of his career are given. 10 refs., 1 fig

  8. Praise for the prize - Hopes for peace: World leaders react

    2006-01-01

    This article presents highlights of words of praise and congratulations for the IAEA and its Director General up on the awarding of the 2005 Nobel Peace Prize. The list include Mr. Kofi Annan, the Secretary General of the UN; Mr. Hans Blix, Director General and Chief UN Weapons Inspector in Iraq; Ms. Condoleezza rice, US Secretary of State; Mr. Jacques Chirac, President of France and the European Commission

  9. Conversational AI: The Science Behind the Alexa Prize

    Ram, Ashwin; Prasad, Rohit; Khatri, Chandra; Venkatesh, Anu; Gabriel, Raefer; Liu, Qing; Nunn, Jeff; Hedayatnia, Behnam; Cheng, Ming; Nagar, Ashish; King, Eric; Bland, Kate; Wartick, Amanda; Pan, Yi; Song, Han

    2018-01-01

    Conversational agents are exploding in popularity. However, much work remains in the area of social conversation as well as free-form conversation over a broad range of domains and topics. To advance the state of the art in conversational AI, Amazon launched the Alexa Prize, a 2.5-million-dollar university competition where sixteen selected university teams were challenged to build conversational agents, known as socialbots, to converse coherently and engagingly with humans on popular topics ...

  10. Student film clinches top prize in film competition

    Elliott, Jean

    2006-01-01

    Virginia Tech senior Tim Leaton earned the top prize in the widely acclaimed Film Your Issue (FYI) competition - an eight-week paid internship at Disney Studios in Los Angeles. Leaton's one-minute film, "Orphans in Africa," won the nationwide contest, an initiative to encourage young Americans, age 18 to 26, to engage in social issues and add their voices to the public dialogue.

  11. Heavy ion collisions and cosmology

    Floerchinger, Stefan

    2016-12-15

    There are interesting parallels between the physics of heavy ion collisions and cosmology. Both systems are out-of-equilibrium and relativistic fluid dynamics plays an important role for their theoretical description. From a comparison one can draw interesting conclusions for both sides. For heavy ion physics it could be rewarding to attempt a theoretical description of fluid perturbations similar to cosmological perturbation theory. In the context of late time cosmology, it could be interesting to study dissipative properties such as shear and bulk viscosity and corresponding relaxation times in more detail. Knowledge and experience from heavy ion physics could help to constrain the microscopic properties of dark matter from observational knowledge of the cosmological fluid properties.

  12. Thermodynamics in Loop Quantum Cosmology

    Li, L.F.; Zhu, J.Y.

    2009-01-01

    Loop quantum cosmology (LQC) is very powerful to deal with the behavior of early universe. Moreover, the effective loop quantum cosmology gives a successful description of the universe in the semiclassical region. We consider the apparent horizon of the Friedmann-Robertson-Walker universe as a thermodynamical system and investigate the thermodynamics of LQC in the semiclassical region. The effective density and effective pressure in the modified Friedmann equation from LQC not only determine the evolution of the universe in LQC scenario but also are actually found to be the thermodynamic quantities. This result comes from the energy definition in cosmology (the Misner-Sharp gravitational energy) and is consistent with thermodynamic laws. We prove that within the framework of loop quantum cosmology, the elementary equation of equilibrium thermodynamics is still valid.

  13. Modernism and cosmology absurd lights

    Ebury, Katherine

    2014-01-01

    Through examining the work of W. B. Yeats, James Joyce, and Samuel Beckett, Katherine Ebury shows cosmology had a considerable impact on modernist creative strategies, developing alternative reading models of difficult texts such as Finnegans Wake and 'The Trilogy'.

  14. Newtonian cosmology Newton would understand

    Lemons, D.S.

    1988-01-01

    Isaac Newton envisioned a static, infinite, and initially uniform, zero field universe that was gravitationally unstable to local condensations of matter. By postulating the existence of such a universe and using it as a boundary condition on Newtonian gravity, a new field equation for gravity is derived, which differs from the classical one by a time-dependent cosmological term proportional to the average mass density of the universe. The new field equation not only makes Jeans' analysis of the gravitational instability of a Newtonian universe consistent, but also gives rise to a family of Newtonian evolutionary cosmologies parametrized by a time-invariant expansion velocity. This Newtonian cosmology contrasts with both 19th-century ones and with post general relativity Newtonian cosmology

  15. Introduction. Cosmology meets condensed matter.

    Kibble, T W B; Pickett, G R

    2008-08-28

    At first sight, low-temperature condensed-matter physics and early Universe cosmology seem worlds apart. Yet, in the last few years a remarkable synergy has developed between the two. It has emerged that, in terms of their mathematical description, there are surprisingly close parallels between them. This interplay has been the subject of a very successful European Science Foundation (ESF) programme entitled COSLAB ('Cosmology in the Laboratory') that ran from 2001 to 2006, itself built on an earlier ESF network called TOPDEF ('Topological Defects: Non-equilibrium Field Theory in Particle Physics, Condensed Matter and Cosmology'). The articles presented in this issue of Philosophical Transactions A are based on talks given at the Royal Society Discussion Meeting 'Cosmology meets condensed matter', held on 28 and 29 January 2008. Many of the speakers had participated earlier in the COSLAB programme, but the strength of the field is illustrated by the presence also of quite a few new participants.

  16. Cosmological principles. II. Physical principles

    Harrison, E.R.

    1974-01-01

    The discussion of cosmological principle covers the uniformity principle of the laws of physics, the gravitation and cognizability principles, and the Dirac creation, chaos, and bootstrap principles. (U.S.)

  17. Cosmology and unified gauge theory

    Oraifeartaigh, L.

    1981-09-01

    Theoretical points in common between cosmology and unified gauge theory (UGT) are reviewed, with attention given to areas of one which have proven useful for the other. The underlying principles for both theoretical frameworks are described, noting the differences in scale, i.e., 10 to the 25th cm in cosmology and 10 to the -15th cm for UGT. Cosmology has produced bounds on the number of existing neutrino species, and also on the mass of neutrinos, two factors of interest in particle physics. Electrons, protons, and neutrinos, having been spawned from the same massive leptons, each composed of three quarks, have been predicted to be present in equal numbers in the Universe by UGT, in line with necessities of cosmology. The Grand UGT also suggests specific time scales for proton decay, thus accounting for the observed baryon assymmetry.

  18. Evolution in bouncing quantum cosmology

    Mielczarek, Jakub; Piechocki, Włodzimierz

    2012-01-01

    We present the method of describing an evolution in quantum cosmology in the framework of the reduced phase space quantization of loop cosmology. We apply our method to the flat Friedmann-Robertson-Walker model coupled to a massless scalar field. We identify the physical quantum Hamiltonian that is positive-definite and generates globally a unitary evolution of the considered quantum system. We examine the properties of expectation values of physical observables in the process of the quantum big bounce transition. The dispersion of evolved observables is studied for the Gaussian state. Calculated relative fluctuations enable an examination of the semi-classicality conditions and possible occurrence of the cosmic forgetfulness. Preliminary estimations based on the cosmological data suggest that there was no cosmic amnesia. Presented results are analytical, and numerical computations are only used for the visualization purposes. Our method may be generalized to sophisticated cosmological models including the Bianchi-type universes. (paper)

  19. Precision cosmology and the landscape

    Bousso, Raphael; Bousso, Raphael

    2006-01-01

    After reviewing the cosmological constant problem--why is Lambda not huge?--I outline the two basic approaches that had emerged by the late 1980s, and note that each made a clear prediction. Precision cosmological experiments now indicate that the cosmological constant is nonzero. This result strongly favors the environmental approach, in which vacuum energy can vary discretely among widely separated regions in the universe. The need to explain this variation from first principles constitutes an observational constraint on fundamental theory. I review arguments that string theory satisfies this constraint, as it contains a dense discretuum of metastable vacua. The enormous landscape of vacua calls for novel, statistical methods of deriving predictions, and it prompts us to reexamine our description of spacetime on the largest scales. I discuss the effects of cosmological dynamics, and I speculate that weighting vacua by their entropy production may allow for prior-free predictions that do not resort to explicitly anthropic arguments

  20. Chaos, decoherence and quantum cosmology

    Calzetta, Esteban

    2012-01-01

    In this topical review we discuss the connections between chaos, decoherence and quantum cosmology. We understand chaos as classical chaos in systems with a finite number of degrees of freedom, decoherence as environment induced decoherence and quantum cosmology as the theory of the Wheeler-DeWitt equation or else the consistent history formulation thereof, first in mini super spaces and later through its extension to midi super spaces. The overall conclusion is that consideration of decoherence is necessary (and probably sufficient) to sustain an interpretation of quantum cosmology based on the wavefunction of the Universe adopting a Wentzel-Kramers-Brillouin form for large Universes, but a definitive account of the semiclassical transition in classically chaotic cosmological models is not available in the literature yet. (topical review)

  1. Physical and Relativistic Numerical Cosmology.

    Anninos, Peter

    1998-01-01

    In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark-hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

  2. Physical and Relativistic Numerical Cosmology

    Peter Anninos

    1998-01-01

    Full Text Available In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark--hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

  3. Three Studies in Epicurean Cosmology

    Bakker, F.A.

    2010-01-01

    This dissertation consists of three studies dealing with various aspects of Epicurean cosmology. The first study discusses the Epicurean practice of explaining astronomical and meteorological phenomena by multiple alternative theories. The second study compares the meteorological accounts of

  4. Bimetric gravity is cosmologically viable

    Yashar Akrami

    2015-09-01

    Full Text Available Bimetric theory describes gravitational interactions in the presence of an extra spin-2 field. Previous work has suggested that its cosmological solutions are generically plagued by instabilities. We show that by taking the Planck mass for the second metric, Mf, to be small, these instabilities can be pushed back to unobservably early times. In this limit, the theory approaches general relativity with an effective cosmological constant which is, remarkably, determined by the spin-2 interaction scale. This provides a late-time expansion history which is extremely close to ΛCDM, but with a technically-natural value for the cosmological constant. We find Mf should be no larger than the electroweak scale in order for cosmological perturbations to be stable by big-bang nucleosynthesis. We further show that in this limit the helicity-0 mode is no longer strongly-coupled at low energy scales.

  5. Nobel prize-winner Heinrich Rohrer visits CERN

    2008-01-01

    The Nobel prize-winner Heinrich Rohrer met young scientists on a recent visit to the Laboratory. From left to right: Xavier Gréhant (CERN Openlab), Ewa Stanecka (ATLAS), Magda Kowalska (ISOLDE), Heinrich Rohrer, Stéphanie Beauceron (CMS) and Ana Gago Da Silva (UNOSAT).Heinrich Rohrer, who shared the 1986 Nobel prize for physics with Gerd Binnig for the design of the scanning tunnelling microscope, visited CERN on 25 June. Welcomed by the Director-General, Robert Aymar, he visited the ATLAS cavern and control room, the Computer Centre, the Unosat project, the Antimatter Decelerator and ISOLDE. At the end of his visit, he voiced his admiration for CERN and its personnel. As a renowned Nobel prize-winner Heinrich Rohrer has the opportunity to pass on his experience and enthusiasm to young scientists. During the evening meal, at which he met five young physicists and computer scientists, who were delighted with the chance to talk to him, he stressed the importance for re...

  6. HAWKING'S Theory of Quantum Cosmology

    Zhi, Fang Li; Chao, Wu Zhong

    The most important problem in cosmology is the birth of the universe. Recently Hartle and Hawking put forward a ground state proposal for the quantum state of the universe which incorporates the idea that the universe must come from nothing. Many models have been discussed in quantum cosmology with this boundary condition. It has been shown that every model is a step towards to a realistic universe, i.e. a 4-dimensional isotropic universe with a long inflationary stage.

  7. Quantum cosmology on the worldsheet

    Cooper, A.R.; Susskind, L.; Thorlacius, L.

    1991-08-01

    Two-dimensional quantum gravity coupled to conformally invariant matter central c > 25 provides a toy model for quantum gravity in four dimensions. Two-dimensional quantum cosmology can thus be studied in terms of string theory in background fields. The large scale cosmological constant depends on non-linear dynamics in the string theory target space and does not appear to be suppressed by wormhole effects. 13 refs

  8. Higgs Physics and Cosmology

    Roberts, Alex

    2016-08-01

    Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and outcomes of particular experiments, according to a single probability formula. This provides complete unification of the eternally inflating multiverse and many worlds in quantum mechanics. We elucidate how cosmological parameters can be calculated in this framework, and study the probability distribution for the value of the cosmological constant. We consider both positive and negative values, and find that the observed value is consistent with the calculated distribution at an order of magnitude level. In particular, in contrast to the case of earlier measure proposals, our framework prefers a positive cosmological constant over a negative one. These results depend only moderately on how we model galaxy formation and life evolution therein. We explore supersymmetric theories in which the Higgs mass is boosted by the non-decoupling D-terms of an extended U(1) X gauge symmetry, defined here to be a general linear combination of hypercharge, baryon number, and lepton number. Crucially, the gauge coupling, gX, is bounded from below to accommodate the Higgs mass, while the quarks and leptons are required by gauge invariance to carry non-zero charge under U(1)X. This induces an irreducible rate, sigmaBR, for pp → X → ll relevant to existing and future resonance searches, and gives rise to higher dimension operators that are stringently constrained by precision electroweak measurements. Combined, these bounds define a maximally allowed region in the space of observables, (sigmaBR, mX), outside of which is excluded by naturalness and experimental limits. If natural supersymmetry utilizes non-decoupling D-terms, then the associated X boson can only be observed within this window, providing a model independent 'litmus test' for this broad

  9. Was Newtonian cosmology really inconsistent?

    Vickers, Peter

    This paper follows up a debate as to the consistency of Newtonian cosmology. Whereas Malament [(1995). Is Newtonian cosmology really inconsistent? Philosophy of Science 62, 489-510] has shown that Newtonian cosmology is not inconsistent, to date there has been no analysis of Norton's claim [(1995). The force of Newtonian cosmology: Acceleration is relative. Philosophy of Science 62, 511-522.] that Newtonian cosmology was inconsistent prior to certain advances in the 1930s, and in particular prior to Seeliger's seminal paper of Seeliger [(1895). Über das Newton'sche Gravitationsgesetz. Astronomische Nachrichten 137 (3273), 129-136.] In this paper I agree that there are assumptions, Newtonian and cosmological in character, and relevant to the real history of science, which are inconsistent. But there are some important corrections to make to Norton's account. Here I display for the first time the inconsistencies-four in total-in all their detail. Although this extra detail shows there to be several different inconsistencies, it also goes some way towards explaining why they went unnoticed for 200 years.

  10. Quantum cosmology and baby universes

    Grishchuk, L.P.

    1990-01-01

    The contributed papers presented to the workshop on ''Quantum Cosmology and Baby Universes'' have demonstrated the great interest in, and rapid development of, the field of quantum cosmology. In my view, there are at least three areas of active research at present. The first area can be defined as that of practical calculations. Here researchers are dealing with the basic quantum cosmological equation, which is the Wheeler-DeWitt equation. They try to classify all possible solutions to the Wheeler-DeWitt equation or seek a specific integration contour in order to select one particular wave function or generalize the simple minisuperspace models to more complicated cases, including various inhomogeneities, anisotropies, etc. The second area of research deals with the interpretational issues of quantum cosmology. There are still many questions about how to extract the observational consequences from a given cosmological wave function, the role of time in quantum cosmology, and how to reformulate the rules of quantum mechanics in such a way that they could be applicable to the single system which is our Universe. The third area of research is concerned with the so-called ''third quantization'' of gravity. In this approach a wave function satisfying the Wheeler-DeWitt equation becomes an operator acting on a Wave Function of the many-universes system. Within this approach one operates with Euclidean worm-holes joining different Lorentzian universes. (author)

  11. Parameterized post-Newtonian cosmology

    Sanghai, Viraj A A; Clifton, Timothy

    2017-01-01

    Einstein’s theory of gravity has been extensively tested on solar system scales, and for isolated astrophysical systems, using the perturbative framework known as the parameterized post-Newtonian (PPN) formalism. This framework is designed for use in the weak-field and slow-motion limit of gravity, and can be used to constrain a large class of metric theories of gravity with data collected from the aforementioned systems. Given the potential of future surveys to probe cosmological scales to high precision, it is a topic of much contemporary interest to construct a similar framework to link Einstein’s theory of gravity and its alternatives to observations on cosmological scales. Our approach to this problem is to adapt and extend the existing PPN formalism for use in cosmology. We derive a set of equations that use the same parameters to consistently model both weak fields and cosmology. This allows us to parameterize a large class of modified theories of gravity and dark energy models on cosmological scales, using just four functions of time. These four functions can be directly linked to the background expansion of the universe, first-order cosmological perturbations, and the weak-field limit of the theory. They also reduce to the standard PPN parameters on solar system scales. We illustrate how dark energy models and scalar-tensor and vector-tensor theories of gravity fit into this framework, which we refer to as ‘parameterized post-Newtonian cosmology’ (PPNC). (paper)

  12. Cosmology of a charged universe

    Barnes, A.

    1979-01-01

    The Proca generalization of electrodynamics admits the possibility that the universe could possess a net electric charge uniformly distributed throughout space, while possessing no electric field. A charged intergalactic (and intragalactic) medium of this kind could contain enough energy to be of cosmological importance. A general-relativistic model of cosmological expansion dominated by such a charged background has been calculated, and is consistent with present observational limits on the Hubble constant, the decleration parameter, and the age of the universe. However, if this cosmology applied at the present epoch, the very early expansion of the universe would have been much more rapid than in conventional ''big bang'' cosmologies, too rapid for cosmological nucleosynthesis or thermalization of the background radiation to have occurred. Hence, domination of the present expansion by background charge appears to be incompatible with the 3 K background and big-bang production of light elements. If the present background charge density were sufficiently small (but not strictly zero), expansion from the epoch of nucleosynthesis would proceed according to the conventional scenario, but the energy due to the background charge would have dominated at some earlier epoch. This last possibility leads to equality of pressure and energy density in the primordial universe, a condition of special significance in certain cosmological theories

  13. Parameterized post-Newtonian cosmology

    Sanghai, Viraj A. A.; Clifton, Timothy

    2017-03-01

    Einstein’s theory of gravity has been extensively tested on solar system scales, and for isolated astrophysical systems, using the perturbative framework known as the parameterized post-Newtonian (PPN) formalism. This framework is designed for use in the weak-field and slow-motion limit of gravity, and can be used to constrain a large class of metric theories of gravity with data collected from the aforementioned systems. Given the potential of future surveys to probe cosmological scales to high precision, it is a topic of much contemporary interest to construct a similar framework to link Einstein’s theory of gravity and its alternatives to observations on cosmological scales. Our approach to this problem is to adapt and extend the existing PPN formalism for use in cosmology. We derive a set of equations that use the same parameters to consistently model both weak fields and cosmology. This allows us to parameterize a large class of modified theories of gravity and dark energy models on cosmological scales, using just four functions of time. These four functions can be directly linked to the background expansion of the universe, first-order cosmological perturbations, and the weak-field limit of the theory. They also reduce to the standard PPN parameters on solar system scales. We illustrate how dark energy models and scalar-tensor and vector-tensor theories of gravity fit into this framework, which we refer to as ‘parameterized post-Newtonian cosmology’ (PPNC).

  14. [The 69th Congress-urologists nominated for the Nobel Prize : Not everyone got a prize: four biographical sketches].

    Moll, F H; Halling, T; Krischel, M; Hansson, N; Fangerau, H

    2017-09-01

    Our research group has reconstructed why the board certified urologists Werner Forssmann (1904-1979) and Charles Huggins (1901-1997) received the Nobel Prize in physiology or medicine (1956, and 1966, respectively). But the history of "Urology and the Nobel Prize" is in fact more multifaceted than the success stories of these two laureates suggest. James Israel (1848-1926), Berlin, Félix Guyon (1831-1920), Paris, Peter J. Freyer (1852-1921), London and Edwin Beer (1876-1938), New York were nominated for the award during the first three decades of the 20th century. Their candidacies mirror trends among leading urologists during the time when urology became a specialty in its own right.

  15. Crucial test of the Dirac cosmologies

    Steigman, G.

    1978-01-01

    In a cosmology consistent with the Cosmological Principle (large scale, statistical isotropy and homogeneity of the universe), a Planck spectrum is not preserved as the universe evolves unless the number of photons in a comoving volume is conserved. It is shown that a large class of cosmological models based on Dirac's Large Numbers Hypothesis (LNH) violate this constraint. The observed isotropy and spectral distribution of the microwave background radiation thus provide a crucial test of such cosmologies. After reviewing the LNH, the general evolution of radiation spectra in cosmologies consistent with the cosmological principle is outlined. It is shown that the predicted deviations from a Planck spectrum for Dirac cosmologies (as well as for ''tired-light'' cosmologies) are enormous. The Planckian (or near-Planckian) spectral form for the microwave radiation provides a crucial test, failed by such cosmologies

  16. Axion cold dark matter in nonstandard cosmologies

    Visinelli, Luca; Gondolo, Paolo

    2010-01-01

    We study the parameter space of cold dark matter axions in two cosmological scenarios with nonstandard thermal histories before big bang nucleosynthesis: the low-temperature reheating (LTR) cosmology and the kination cosmology. If the Peccei-Quinn symmetry breaks during inflation, we find more allowed parameter space in the LTR cosmology than in the standard cosmology and less in the kination cosmology. On the contrary, if the Peccei-Quinn symmetry breaks after inflation, the Peccei-Quinn scale is orders of magnitude higher than standard in the LTR cosmology and lower in the kination cosmology. We show that the axion velocity dispersion may be used to distinguish some of these nonstandard cosmologies. Thus, axion cold dark matter may be a good probe of the history of the Universe before big bang nucleosynthesis.

  17. Dark matter and cosmology

    Schramm, D.N.

    1992-03-01

    The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ``cold`` and ``hot`` non-baryonic candidates is shown to depend on the assumed ``seeds`` that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

  18. Dark matter and cosmology

    Schramm, D.N.

    1992-03-01

    The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between cold'' and hot'' non-baryonic candidates is shown to depend on the assumed seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

  19. Cosmology for the curious

    Perlov, Delia

    2017-01-01

    This book is an introductory text for all those wishing to learn about modern views of the cosmos. Our universe originated in a great explosion – the big bang. For nearly a century cosmologists have studied the aftermath of this explosion: how the universe expanded and cooled down, and how galaxies were gradually assembled by gravity. The nature of the bang itself has come into focus only relatively recently. It is the subject of the theory of cosmic inflation, which was developed in the last few decades and has led to a radically new global view of the universe. Students and other interested readers will find here a non-technical but conceptually rigorous account of modern cosmological ideas - describing what we know, and how we know it. One of the book's central themes is the scientific quest to find answers to the ultimate cosmic questions: Is the universe finite or infinite? Has it existed forever? If not, when and how did it come into being? Will it ever end? The book is based on the undergraduate cour...

  20. Entropy, matter, and cosmology.

    Prigogine, I; Géhéniau, J

    1986-09-01

    The role of irreversible processes corresponding to creation of matter in general relativity is investigated. The use of Landau-Lifshitz pseudotensors together with conformal (Minkowski) coordinates suggests that this creation took place in the early universe at the stage of the variation of the conformal factor. The entropy production in this creation process is calculated. It is shown that these dissipative processes lead to the possibility of cosmological models that start from empty conditions and gradually build up matter and entropy. Gravitational entropy takes a simple meaning as associated to the entropy that is necessary to produce matter. This leads to an extension of the third law of thermodynamics, as now the zero point of entropy becomes the space-time structure out of which matter is generated. The theory can be put into a convenient form using a supplementary "C" field in Einstein's field equations. The role of the C field is to express the coupling between gravitation and matter leading to irreversible entropy production.

  1. Early cosmology constrained

    Verde, Licia; Jimenez, Raul [Institute of Cosmos Sciences, University of Barcelona, IEEC-UB, Martí Franquès, 1, E08028 Barcelona (Spain); Bellini, Emilio [University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Pigozzo, Cassio [Instituto de Física, Universidade Federal da Bahia, Salvador, BA (Brazil); Heavens, Alan F., E-mail: liciaverde@icc.ub.edu, E-mail: emilio.bellini@physics.ox.ac.uk, E-mail: cpigozzo@ufba.br, E-mail: a.heavens@imperial.ac.uk, E-mail: raul.jimenez@icc.ub.edu [Imperial Centre for Inference and Cosmology (ICIC), Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2017-04-01

    We investigate our knowledge of early universe cosmology by exploring how much additional energy density can be placed in different components beyond those in the ΛCDM model. To do this we use a method to separate early- and late-universe information enclosed in observational data, thus markedly reducing the model-dependency of the conclusions. We find that the 95% credibility regions for extra energy components of the early universe at recombination are: non-accelerating additional fluid density parameter Ω{sub MR} < 0.006 and extra radiation parameterised as extra effective neutrino species 2.3 < N {sub eff} < 3.2 when imposing flatness. Our constraints thus show that even when analyzing the data in this largely model-independent way, the possibility of hiding extra energy components beyond ΛCDM in the early universe is seriously constrained by current observations. We also find that the standard ruler, the sound horizon at radiation drag, can be well determined in a way that does not depend on late-time Universe assumptions, but depends strongly on early-time physics and in particular on additional components that behave like radiation. We find that the standard ruler length determined in this way is r {sub s} = 147.4 ± 0.7 Mpc if the radiation and neutrino components are standard, but the uncertainty increases by an order of magnitude when non-standard dark radiation components are allowed, to r {sub s} = 150 ± 5 Mpc.

  2. Cosmology with exponential potentials

    Kehagias, Alex; Kofinas, Georgios

    2004-01-01

    We examine in the context of general relativity the dynamics of a spatially flat Robertson-Walker universe filled with a classical minimally coupled scalar field φ of exponential potential V(φ) ∼ exp(-μφ) plus pressureless baryonic matter. This system is reduced to a first-order ordinary differential equation for Ω φ (w φ ) or q(w φ ), providing direct evidence on the acceleration/deceleration properties of the system. As a consequence, for positive potentials, passage into acceleration not at late times is generically a feature of the system for any value of μ, even when the late-times attractors are decelerating. Furthermore, the structure formation bound, together with the constraints Ω m0 ∼ 0.25 - 0.3, -1 ≤ w φ0 ≤ -0.6, provides, independently of initial conditions and other parameters, the necessary condition 0 N , while the less conservative constraint -1 ≤ w φ ≤ -0.93 gives 0 N . Special solutions are found to possess intervals of acceleration. For the almost cosmological constant case w φ ∼ -1, the general relation Ω φ (w φ ) is obtained. The generic (nonlinearized) late-times solution of the system in the plane (w φ , Ω φ ) or (w φ , q) is also derived

  3. Dark matter and cosmology

    Schramm, D.N.

    1992-03-01

    The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the Ω = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ''cold'' and ''hot'' non-baryonic candidates is shown to depend on the assumed ''seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed

  4. Nuclear physics and cosmology

    Schramm, D.N.

    1989-12-01

    Nuclear physics has provided one of the 2 critical observational tests of all Big Bang cosmology, namely Big Bang Nucleosynthesis. Furthermore, this same nuclear physics input enables a prediction to be made about one of the most fundamental physics questions of all, the number of elementary particle families. This paper reviews the standard Big Bang Nucleosynthesis arguments. The primordial He abundance is inferred from He--C and He--N and He--O correlations. The strengthened Li constraint as well as 2 D plus 3 He are used to limit the baryon density. This limit is the key argument behind the need for non-baryonic dark matter. The allowed number of neutrino families, N ν , is delineated using the new neutron lifetime value of τ n = 890 ± 4s (τ 1/2 = 10.3 min). The formal statistical result is N ν = 2.6 ± 0.3 (1σ) providing a reasonable fit (1.3σ) to 3 families but making a fourth light (m ν approx-lt 10 MeV) neutrino family exceedingly unlikely (approx-gt 4.7σ) (barring significant systematic errors either in D + 3 He, and Li and/or 4 He and/or τ n ). It is also shown that uncertainties induced by postulating a first-order quark-hadron phase transition do not seriously affect the conclusions. 21 refs., 3 figs

  5. Cosmological quantum entanglement

    Martín-Martínez, Eduardo; Menicucci, Nicolas C

    2012-01-01

    We review recent literature on the connection between quantum entanglement and cosmology, with an emphasis on the context of expanding universes. We discuss recent theoretical results reporting on the production of entanglement in quantum fields due to the expansion of the underlying spacetime. We explore how these results are affected by the statistics of the field (bosonic or fermionic), the type of expansion (de Sitter or asymptotically stationary), and the coupling to spacetime curvature (conformal or minimal). We then consider the extraction of entanglement from a quantum field by coupling to local detectors and how this procedure can be used to distinguish curvature from heating by their entanglement signature. We review the role played by quantum fluctuations in the early universe in nucleating the formation of galaxies and other cosmic structures through their conversion into classical density anisotropies during and after inflation. We report on current literature attempting to account for this transition in a rigorous way and discuss the importance of entanglement and decoherence in this process. We conclude with some prospects for further theoretical and experimental research in this area. These include extensions of current theoretical efforts, possible future observational pursuits, and experimental analogues that emulate these cosmic effects in a laboratory setting. (paper)

  6. Nuclear physics and cosmology

    Schramm, David N.

    1989-01-01

    Nuclear physics has provided one of two critical observational tests of all Big Bang cosmology, namely Big Bang Nucleosynthesis. Furthermore, this same nuclear physics input enables a prediction to be made about one of the most fundamental physics questions of all, the number of elementary particle families. The standard Big Bang Nucleosynthesis arguments are reviewed. The primordial He abundance is inferred from He-C and He-N and He-O correlations. The strengthened Li constraint as well as D-2 plus He-3 are used to limit the baryon density. This limit is the key argument behind the need for non-baryonic dark matter. The allowed number of neutrino families, N(nu), is delineated using the new neutron lifetime value of tau(n) = 890 + or - 4s (tau(1/2) = 10.3 min). The formal statistical result is N(nu) = 2.6 + or - 0.3 (1 sigma), providing a reasonable fit (1.3 sigma) to three families but making a fourth light (m(nu) less than or equal to 10 MeV) neutrino family exceedly unlikely (approx. greater than 4.7 sigma). It is also shown that uncertainties induced by postulating a first-order quark-baryon phase transition do not seriously affect the conclusions.

  7. Cosmological helium production simplified

    Bernstein, J.; Brown, L.S.; Feinberg, G.

    1988-01-01

    We present a simplified model of helium synthesis in the early universe. The purpose of the model is to explain clearly the physical ideas relevant to the cosmological helium synthesis, in a manner that does not overlay these ideas with complex computer calculations. The model closely follows the standard calculation, except that it neglects the small effect of Fermi-Dirac statistics for the leptons. We also neglect the temperature difference between photons and neutrinos during the period in which neutrons and protons interconvert. These approximations allow us to express the neutron-proton conversion rates in a closed form, which agrees to 10% accuracy or better with the exact rates. Using these analytic expressions for the rates, we reduce the calculation of the neutron-proton ratio as a function of temperature to a simple numerical integral. We also estimate the effect of neutron decay on the helium abundance. Our result for this quantity agrees well with precise computer calculations. We use our semi-analytic formulas to determine how the predicted helium abundance varies with such parameters as the neutron life-time, the baryon to photon ratio, the number of neutrino species, and a possible electron-neutrino chemical potential. 19 refs., 1 fig., 1 tab

  8. New ekpyrotic cosmology

    Buchbinder, Evgeny I.; Khoury, Justin; Ovrut, Burt A.

    2007-01-01

    In this paper, we present a new scenario of the early universe that contains a pre-big bang ekpyrotic phase. By combining this with a ghost condensate, the theory explicitly violates the null energy condition without developing any ghostlike instabilities. Thus the contracting universe goes through a nonsingular bounce and evolves smoothly into the expanding post-big bang phase. The curvature perturbation acquires a scale-invariant spectrum well before the bounce in this scenario. It is sourced by the scale-invariant entropy perturbation engendered by two ekpyrotic scalar fields, a mechanism recently proposed by Lehners et al. Since the background geometry is nonsingular at all times, the curvature perturbation remains nearly constant on superhorizon scales. It emerges from the bounce unscathed and imprints a scale-invariant spectrum of density fluctuations in the matter-radiation fluid at the onset of the hot big bang phase. The ekpyrotic potential can be chosen so that the spectrum has a red tilt, in accordance with the recent data from WMAP. As in the original ekpyrotic scenario, the model predicts a negligible gravity wave signal on all observable scales. As such ''new ekpyrotic cosmology'' provides a consistent and distinguishable alternative to inflation to account for the origin of the seeds of large-scale structure

  9. Implications of a decay law for the cosmological constant in higher dimensional cosmology and cosmological wormholes

    Rami, El-Nabulsi Ahmad

    2009-01-01

    Higher dimensional cosmological implications of a decay law for the cosmological constant term are analyzed. Three independent cosmological models are explored mainly: 1) In the first model, the effective cosmological constant was chosen to decay with times like Δ effective = Ca -2 + D(b/a I ) 2 where a I is an arbitrary scale factor characterizing the isotropic epoch which proceeds the graceful exit period. Further, the extra-dimensional scale factor decays classically like b(t) approx. a x (t), x is a real negative number. 2) In the second model, we adopt in addition to Δ effective = Ca -2 + D(b/a I ) 2 the phenomenological law b(t) = a(t)exp( -Qt) as we expect that at the origin of time, there is no distinction between the visible and extra dimensions; Q is a real number. 3) In the third model, we study a Δ - decaying extra-dimensional cosmology with a static traversable wormhole in which the four-dimensional Friedmann-Robertson-Walker spacetime is subject to the conventional perfect fluid while the extra-dimensional part is endowed by an exotic fluid violating strong energy condition and where the cosmological constant in (3+n+1) is assumed to decays like Δ(a) = 3Ca -2 . The three models are discussed and explored in some details where many interesting points are revealed. (author)

  10. Cosmological tests of modified gravity.

    Koyama, Kazuya

    2016-04-01

    We review recent progress in the construction of modified gravity models as alternatives to dark energy as well as the development of cosmological tests of gravity. Einstein's theory of general relativity (GR) has been tested accurately within the local universe i.e. the Solar System, but this leaves the possibility open that it is not a good description of gravity at the largest scales in the Universe. This being said, the standard model of cosmology assumes GR on all scales. In 1998, astronomers made the surprising discovery that the expansion of the Universe is accelerating, not slowing down. This late-time acceleration of the Universe has become the most challenging problem in theoretical physics. Within the framework of GR, the acceleration would originate from an unknown dark energy. Alternatively, it could be that there is no dark energy and GR itself is in error on cosmological scales. In this review, we first give an overview of recent developments in modified gravity theories including f(R) gravity, braneworld gravity, Horndeski theory and massive/bigravity theory. We then focus on common properties these models share, such as screening mechanisms they use to evade the stringent Solar System tests. Once armed with a theoretical knowledge of modified gravity models, we move on to discuss how we can test modifications of gravity on cosmological scales. We present tests of gravity using linear cosmological perturbations and review the latest constraints on deviations from the standard [Formula: see text]CDM model. Since screening mechanisms leave distinct signatures in the non-linear structure formation, we also review novel astrophysical tests of gravity using clusters, dwarf galaxies and stars. The last decade has seen a number of new constraints placed on gravity from astrophysical to cosmological scales. Thanks to on-going and future surveys, cosmological tests of gravity will enjoy another, possibly even more, exciting ten years.

  11. Video of Christian Skau and Martin Raussen's interview with the Abel Prize Winner John Milnor

    Skau, Christian

    2011-01-01

    The television interview with Abel Laureate John Milnor that was broadcasted on Norwegian television in June is now available on the Abel Prize multimedia page. John Milnor received the Abel Prize «for pioneering discoveries in topology, geometry and algebra» to quote the Abel Committee. King...... Harald presented the Abel Prize to John Milnor at the award ceremony in Oslo, Norway on 24 May. Before the interview there is a short presentation of the award ceremony. John Milnor is interviewed by Martin Raussen and Christian Skau. The Abel Prize that carries a cash award of NOK 6 million (about EUR...

  12. The Rolf and Gertrud Dahlgren Prize for 2017 Awarded to Hans Walter Lack

    Friis, Ib

    2018-01-01

    The reasons for awarding the Rolf and Gertrud Dahlgren Prize to Hans Walter Lack are summarised and the prize described. It is also mentioned that Rosén's Linnaeus Medal in Gold was awarded to Arne Strid at the same ceremony.......The reasons for awarding the Rolf and Gertrud Dahlgren Prize to Hans Walter Lack are summarised and the prize described. It is also mentioned that Rosén's Linnaeus Medal in Gold was awarded to Arne Strid at the same ceremony....

  13. Partial rip scenario - a cosmology with a growing cosmological term

    Stefancic, H.

    2004-01-01

    A cosmology with the growing cosmological term is considered. If there is no exchange of energy between vacuum and matter components, the requirement of general covariance implies the time dependence of the gravitational constant G. Irrespectively of the exact functional form of the cosmological term growth, the universe ends in a de Sitter regime with a constant asymptotic Λ, but vanishing G. Although there is no divergence of the scale factor in finite time, such as in the 'Big Rip' scenario, gravitationally bound systems eventually become unbound. In the case of systems bound by non-gravitational forces, there is no unbounding effect, as the asymptotic Λ is insufficiently large to disturb these systems

  14. Entropy and cosmology.

    Zucker, M. H.

    This paper is a critical analysis and reassessment of entropic functioning as it applies to the question of whether the ultimate fate of the universe will be determined in the future to be "open" (expanding forever to expire in a big chill), "closed" (collapsing to a big crunch), or "flat" (balanced forever between the two). The second law of thermodynamics declares that entropy can only increase and that this principle extends, inevitably, to the universe as a whole. This paper takes the position that this extension is an unwarranted projection based neither on experience nonfact - an extrapolation that ignores the powerful effect of a gravitational force acting within a closed system. Since it was originally presented by Clausius, the thermodynamic concept of entropy has been redefined in terms of "order" and "disorder" - order being equated with a low degree of entropy and disorder with a high degree. This revised terminology more subjective than precise, has generated considerable confusion in cosmology in several critical instances. For example - the chaotic fireball of the big bang, interpreted by Stephen Hawking as a state of disorder (high entropy), is infinitely hot and, thermally, represents zero entropy (order). Hawking, apparently focusing on the disorderly "chaotic" aspect, equated it with a high degree of entropy - overlooking the fact that the universe is a thermodynamic system and that the key factor in evaluating the big-bang phenomenon is the infinitely high temperature at the early universe, which can only be equated with zero entropy. This analysis resolves this confusion and reestablishes entropy as a cosmological function integrally linked to temperature. The paper goes on to show that, while all subsystems contained within the universe require external sources of energization to have their temperatures raised, this requirement does not apply to the universe as a whole. The universe is the only system that, by itself can raise its own

  15. Cosmological tests of coupled Galileons

    Brax, Philippe; Burrage, Clare; Davis, Anne-Christine; Gubitosi, Giulia

    2015-01-01

    We investigate the cosmological properties of Galileon models which admit Minkowski space as a stable solution in vacuum. This is motivated by stable, positive tension brane world constructions that give rise to Galileons. We include both conformal and disformal couplings to matter and focus on constraints on the theory that arise because of these couplings. The disformal coupling to baryonic matter is extremely constrained by astrophysical and particle physics effects. The disformal coupling to photons induces a cosmological variation of the speed of light and therefore distorsions of the Cosmic Microwave Background spectrum which are known to be very small. The conformal coupling to baryons leads to a variation of particle masses since Big Bang Nucleosynthesis which is also tightly constrained. We consider the background cosmology of Galileon models coupled to Cold Dark Matter (CDM), photons and baryons and impose that the speed of light and particle masses respect the observational bounds on cosmological time scales. We find that requiring that the equation of state for the Galileon models must be close to -1 now restricts severely their parameter space and can only be achieved with a combination of the conformal and disformal couplings. This leads to large variations of particle masses and the speed of light which are not compatible with observations. As a result, we find that cosmological Galileon models are viable dark energy theories coupled to dark matter but their couplings, both disformal and conformal, to baryons and photons must be heavily suppressed making them only sensitive to CDM

  16. Relic gravitons and viscous cosmologies

    Cataldo, Mauricio; Mella, Patricio

    2006-01-01

    Previously it was shown that there exists a class of viscous cosmological models which violate the dominant energy condition for a limited amount of time after which they are smoothly connected to the ordinary radiation era (which preserves the dominant energy conditions). This violation of the dominant energy condition at an early cosmological epoch may influence the slopes of energy spectra of relic gravitons that might be of experimental relevance. However, the bulk viscosity coefficient of these cosmologies became negative during the ordinary radiation era, and then the entropy of the sources driving the geometry decreases with time. We show that in the presence of viscous sources with a linear barotropic equation of state p=γρ we get viscous cosmological models with positive bulk viscous stress during all their evolution, and hence the matter entropy increases with the expansion time. In other words, in the framework of viscous cosmologies, there exist isotropic models compatible with the standard second law of thermodynamics which also may influence the slopes of energy spectra of relic gravitons

  17. Remark on receiving encouraging prize; Shoreisho jusho shokan

    Mizutani, Tomichika [Meji University, Tokyo (Japan)

    1999-07-31

    The 1998 fiscal year Japan Solar Energy Soc. encouraging prize is received this time, and it is really sure of thank you and this winning prize for future research activity with large encouragement, while research activity in the university becomes in the good commemoration. This study also put environmental problem in visual field oil crisis energy resource worldwide new, and it was noticed in the wave energy which was one of the natural energy, it was started. That the wave energy was noticed, when the research of various natural energy was advanced, Over 10 years, it is the idea which was produced by the process in which the mechanics laboratory studies the vibration problem, and it is regarded as connecting with present winning prize as a summing-up of research result kept since the front. In the keyword of 'new{exclamation_point}' it began to leave Mr.Taichi Matsuoka and cooperation of the science graduate student as a partner of the graduation thesis the research the present it was a start from the nothing as a thing of this type. It is negative to advance this study in which the failure was always given here, when the new work began, of Mr.Matsuoka of the passion for the research. Away from the research of the wave power generation, solar light and wind power generation are noticed a little, and I aim at the hybridization of the wave power generation, and the research is advanced. Therefore, the vibration-proof stage for installing sun and wind energy conversion system on the wave-power device at present has been designed. At the end, the gratitude is shown to the everybody who received the enthusiastic guidance for this study. (translated by NEDO)

  18. The world made by Noble prize : chemistry volume II

    2007-06-01

    This book has two parts of items related chemistry. The contents of the first part are Preface, Alfred Bemhard Nobel, Pioneers without Nobel Prize, Garbage Bag, Non-sticky Frying Pan, Nylon Stockings, Plastic Electricity, Synthetic Dyestuff, Gin and Tonic, Soccer Ball, Fertilizer, DDT, Dentifrice, Kimchi, Makgeolli, Ice cream, Anodyne, and firefly. The contents of the second part are PET-MRI, Color photo, Holography, Art diamond, an incandescent lamp and Neon Sign, Imitation works, Alchemy, Nuclear Power plant, Synthetic Oil and Sugar, Propane gas, Water Car, Estate agency Mars, and reference.

  19. Manne Siegbahn and the 1924 Nobel Prize for Physics

    Bergstroem, I.

    1988-01-01

    The Research Institute of Physics celebrates its fiftieth anniversary with a Workshop and Symposium on the Physics of Low-Energy Stored and Trapped Particles. On July 1, 1937, Professor Manne Siegbahn was appointed the first director of the Institute. Because of this celebration a personal account is given of Manne Siegbahn's contribution to atomic structure physics. Comments will also be given on the procedure in the Swedish Academy of Sciences when Siegbahn in 1925 received the 1924 Nobel Prize for Physics 'for his discoveries and research in the field of X-ray spectroscopy'. (orig.)

  20. Chronobiology --2017 Nobel Prize in Physiology or Medicine.

    Yuan, Li; Li, Yi-Rou; Xu, Xiao-Dong

    2018-01-20

    Chronobiology is a field of biology that examines the generation of biological rhythms in various creatures and in many parts of body, and their adaptive fitness to solar- and lunar-related periodic phenomena. The synchronization of internal circadian clocks with external timing signals confers accurate phase response and tissue homeostasis. Herein we state a series of studies on circadian rhythms and introduce the brief history of chronobiology. We also present a detailed timeline of the discoveries on molecular mechanisms controlling circadian rhythm in Drosophila, which was awarded the 2017 Nobel Prize in Physiology or Medicine. The latest findings and new perspectives are further summarized to indicate the significance of circadian research.

  1. Director of IMCS - National Prize Laureate of Moldova

    Editorial board of the "Computer Science Journal of Moldova"

    2012-02-01

    Full Text Available Director of the Institute of Mathematics and Computer Science, Vice Editor-in-Chief of CSJM, and our colleague, D.Hab. Svetlana Cojocaru, in 2011 became the National Prize Laureate of Moldova. In accordance with Government decision, this distinction is given for ``outstanding achievements whose results have substantially enriched science, culture and art, had a considerable contribution to promoting a positive image of the country in the international arena, a significant impact on the development of socio-economic, scientific and technical progress, national and world culture.''

  2. Manne Siegbahn and the 1924 Nobel Prize for Physics

    Bergstroem, I.

    1988-01-01

    The Research Institute of Physics celebrates its fiftieth anniversary with a Workshop and Symposium on the Physics of Low-Energy Stored and Trapped Particles. On July 1, 1937, Professor Manne Siegbahn was appointed the first director of the Institute. Because of this celebration a personal account is given of Manne Siegbahn's contribution to atomic structure physics. Comments will also be given on the procedure in the Swedish Academy of Sciences when Siegbahn in 1925 received the 1924 Nobel Prize for Physics 'for his discoveries and research in the field of X-ray spectroscopy'.

  3. The world made by Noble prize : chemistry volume II

    NONE

    2007-06-15

    This book has two parts of items related chemistry. The contents of the first part are Preface, Alfred Bemhard Nobel, Pioneers without Nobel Prize, Garbage Bag, Non-sticky Frying Pan, Nylon Stockings, Plastic Electricity, Synthetic Dyestuff, Gin and Tonic, Soccer Ball, Fertilizer, DDT, Dentifrice, Kimchi, Makgeolli, Ice cream, Anodyne, and firefly. The contents of the second part are PET-MRI, Color photo, Holography, Art diamond, an incandescent lamp and Neon Sign, Imitation works, Alchemy, Nuclear Power plant, Synthetic Oil and Sugar, Propane gas, Water Car, Estate agency Mars, and reference.

  4. [Women in natural sciences--Nobel Prize winners].

    Zuskin, Eugenija; Mustajbegović, Jadranka; Lipozencić, Jasna; Kolcić, Ivana; Spoljar-Vrzina, Sanja; Polasek, Ozren

    2006-01-01

    Alfred Bernhard Nobel was the founder of the Nobel Foundation, which has been awarding world-known scientists since 1901, for their contribution to the welfare of mankind. The life and accomplishments of Alfred Bernhard Nobel are described as well as scientific achivements of 11 women, Nobel prize winners in the field of physics, chemistry, physiology and/or medicine. They are Marie Sklodowska Curie, Maria Goeppert Mayer, Irene Joliot-Curie, Dorothy Crowfoot Hodgkin, Gerty Theresa Radnitz Cori, Rosalyn Sussman Yalow, Barbara McClintock, Rita Levi-Montalcini, Gertrude Elion, Christine Nusslein-Volhard and Linda B. Buck.

  5. Google Science Fair 2012 : Grand Prize Winner Brittany Wenger

    Maximilien Brice

    2012-01-01

    17-18 age category AND Grand Prize Winner: Brittany Wenger (USA)—“Global Neural Network Cloud Service for Breast Cancer.” Brittany’s project harnesses the power of the cloud to help doctors accurately diagnose breast cancer. Brittany built an application that compares individual test results to an extensive dataset stored in the cloud, allowing doctors to assess tumors using a minimally-invasive procedure. Brittany Michelle Wenger, and her mother, passed through the CERN Control Centre accompanied by Mike Lamont, CERN Beams Department, Operation Group Leader.

  6. Paul Ehrlich: the Nobel Prize in physiology or medicine 1908.

    Piro, Anna; Tagarelli, Antonio; Tagarelli, Giuseppe; Lagonia, Paolo; Quattrone, Aldo

    2008-01-01

    We wish to commemorate Paul Ehrlich on the centennial of his being awarded the Nobel Prize in Physiology or Medicine in 1908. His studies are now considered as milestones in immunology: the morphology of leukocytes; his side-chain theory where he defined the cellular receptor for first time; and his clarification of the difference between serum therapy and chemotherapy. Ehrlich also invented the first chemotherapeutic drug: compound 606, or Salvarsan. We have used some original documents from the Royal Society of London, where Ehrlich was a fellow, and from Leipzig University, where he took a degree in medicine.

  7. The time-dependent prize-collecting arc routing problem

    Black, Dan; Eglese, Richard; Wøhlk, Sanne

    2013-01-01

    with the time of day. Two metaheuristic algorithms, one based on Variable Neighborhood Search and one based on Tabu Search, are proposed and tested for a set of benchmark problems, generated from real road networks and travel time information. Both algorithms are capable of finding good solutions, though......A new problem is introduced named the Time-Dependent Prize-Collecting Arc Routing Problem (TD-PARP). It is particularly relevant to situations where a transport manager has to choose between a number of full truck load pick-ups and deliveries on a road network where travel times change...

  8. Second viscosity effects in cosmology

    Potupa, A.S.

    1978-01-01

    The object of the investigation is to draw attention to two important aspects in the choice of a substance model, namely an allowance for the viscosity and behaviour of the metrics at the later stages of cosmological evolution. It is shown that in homogeneous cosmological models taking into account the viscosity there are solutions which realize interpolation between the Fridman and steady-state regimes. In a closed model a solution is obtained which corresponds to the ''curvature compensation'' regime with an unboundedly increasing radius. The problem of compensation of singularity at t → o is discussed as well as the choice of the equations of state for the early (hadron) stages of cosmological evolution in connection with the hydrodynamic theory of multiple hadron production

  9. Cosmology on a cosmic ring

    Niedermann, Florian; Schneider, Robert

    2015-01-01

    We derive the modified Friedmann equations for a generalization of the Dvali-Gabadadze-Porrati (DGP) model in which the brane has one additional compact dimension. The main new feature is the emission of gravitational waves into the bulk. We study two classes of solutions: first, if the compact dimension is stabilized, the waves vanish and one exactly recovers DGP cosmology. However, a stabilization by means of physical matter is not possible for a tension-dominated brane, thus implying a late time modification of 4D cosmology different from DGP. Second, for a freely expanding compact direction, we find exact attractor solutions with zero 4D Hubble parameter despite the presence of a 4D cosmological constant. The model hence constitutes an explicit example of dynamical degravitation at the full nonlinear level. Without stabilization, however, there is no 4D regime and the model is ruled out observationally, as we demonstrate explicitly by comparing to supernova data

  10. Quantum gravity and quantum cosmology

    Papantonopoulos, Lefteris; Siopsis, George; Tsamis, Nikos

    2013-01-01

    Quantum gravity has developed into a fast-growing subject in physics and it is expected that probing the high-energy and high-curvature regimes of gravitating systems will shed some light on how to eventually achieve an ultraviolet complete quantum theory of gravity. Such a theory would provide the much needed information about fundamental problems of classical gravity, such as the initial big-bang singularity, the cosmological constant problem, Planck scale physics and the early-time inflationary evolution of our Universe.   While in the first part of this book concepts of quantum gravity are introduced and approached from different angles, the second part discusses these theories in connection with cosmological models and observations, thereby exploring which types of signatures of modern and mathematically rigorous frameworks can be detected by experiments. The third and final part briefly reviews the observational status of dark matter and dark energy, and introduces alternative cosmological models.   ...

  11. Working group report: Cosmology and astroparticle physics

    This is the report of the cosmology and astroparticle physics working group ... origin of the accelerating Universe: Dark energy and particle cosmology by Y-Y Keum, .... Neutrino oscillations with two and three mass varying supernova neutrinos ...

  12. The current status of observational cosmology

    in quality, quantity and the scope of cosmological observations. The measurement .... In this article, we limit our attention to the simplest case of a cosmological ... On the large angular scales, the CMB anisotropy directly probes the primordial.

  13. A philosophy for big-bang cosmology.

    McCrea, W H

    1970-10-03

    According to recent developments in cosmology we seem bound to find a model universe like the observed universe, almost independently of how we suppose it started. Such ideas, if valid, provide fresh justification for the procedures of current cosmological theory.

  14. Averaging in spherically symmetric cosmology

    Coley, A. A.; Pelavas, N.

    2007-01-01

    The averaging problem in cosmology is of fundamental importance. When applied to study cosmological evolution, the theory of macroscopic gravity (MG) can be regarded as a long-distance modification of general relativity. In the MG approach to the averaging problem in cosmology, the Einstein field equations on cosmological scales are modified by appropriate gravitational correlation terms. We study the averaging problem within the class of spherically symmetric cosmological models. That is, we shall take the microscopic equations and effect the averaging procedure to determine the precise form of the correlation tensor in this case. In particular, by working in volume-preserving coordinates, we calculate the form of the correlation tensor under some reasonable assumptions on the form for the inhomogeneous gravitational field and matter distribution. We find that the correlation tensor in a Friedmann-Lemaitre-Robertson-Walker (FLRW) background must be of the form of a spatial curvature. Inhomogeneities and spatial averaging, through this spatial curvature correction term, can have a very significant dynamical effect on the dynamics of the Universe and cosmological observations; in particular, we discuss whether spatial averaging might lead to a more conservative explanation of the observed acceleration of the Universe (without the introduction of exotic dark matter fields). We also find that the correlation tensor for a non-FLRW background can be interpreted as the sum of a spatial curvature and an anisotropic fluid. This may lead to interesting effects of averaging on astrophysical scales. We also discuss the results of averaging an inhomogeneous Lemaitre-Tolman-Bondi solution as well as calculations of linear perturbations (that is, the backreaction) in an FLRW background, which support the main conclusions of the analysis

  15. Particle accelerators test cosmological theory

    Schramm, D.N.; Steigman, G.

    1988-01-01

    Over the past decade two subfields of science, cosmology and elementary-particle physics, have become married in a symbiotic relationship that has produced a number of exciting offspring. These offspring are beginning to yield insights on the creation of spacetime and matter at epochs as early as 10 to the minus 43 to 10 to the minus 35 second after the birth of the universe in the primordial explosion known as the big bang. Important clues to the nature of the big bang itself may even come from a theory currently under development, known as the ultimate theory of everything (T.E.O.). A T.E.O. would describe all the interactions among the fundamental particles in a single bold stroke. Now that cosmology ahs begun to make predictions about elementary-particle physics, it has become conceivable that those cosmological predictions could be checked with carefully controlled accelerator experiments. It has taken more than 10 years for accelerators to reach the point where they can do the appropriate experiments, but the experiments are now in fact in progress. The preliminary results confirm the predictions of cosmology. The cosmological prediction the authors have been concerned with pertains to setting limits on the number of fundamental particles of matter. It appears that there are 12 fundamental particles, as well as their corresponding antiparticles. Six of the fundamental particles are quarks. The other six are leptons. The 12 particles are grouped in three families, each family consisting of four members. Cosmology suggests there must be a finite number of families and, further limits the possible range of to small values: only three or at most four families exist. 7 figs

  16. Cosmological dynamics of extended chameleons

    Tamanini, Nicola; Wright, Matthew

    2016-01-01

    We investigate the cosmological dynamics of the recently proposed extended chameleon models at both background and linear perturbation levels. Dynamical systems techniques are employed to fully characterize the evolution of the universe at the largest distances, while structure formation is analysed at sub-horizon scales within the quasi-static approximation. The late time dynamical transition from dark matter to dark energy domination can be well described by almost all extended chameleon models considered, with no deviations from ΛCDM results at both background and perturbation levels. The results obtained in this work confirm the cosmological viability of extended chameleons as alternative dark energy models.

  17. Brane cosmology with curvature corrections

    Kofinas, Georgios; Maartens, Roy; Papantonopoulos, Eleftherios

    2003-01-01

    We study the cosmology of the Randall-Sundrum brane-world where the Einstein-Hilbert action is modified by curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a five-dimensional Gauss-Bonnet curvature term. The combined effect of these curvature corrections to the action removes the infinite-density big bang singularity, although the curvature can still diverge for some parameter values. A radiation brane undergoes accelerated expansion near the minimal scale factor, for a range of parameters. This acceleration is driven by the geometric effects, without an inflation field or negative pressures. At late times, conventional cosmology is recovered. (author)

  18. Baryon symmetric big bang cosmology

    Stecker, F.W.

    1978-01-01

    It is stated that the framework of baryon symmetric big bang (BSBB) cosmology offers our greatest potential for deducting the evolution of the Universe because its physical laws and processes have the minimum number of arbitrary assumptions about initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the Universe and how galaxies and galaxy clusters are formed. BSBB cosmology also provides the only acceptable explanation at present for the origin of the cosmic γ-ray background radiation. (author)

  19. Cosmological dynamics of extended chameleons

    Tamanini, Nicola [Institut de Physique Théorique, CEA-Saclay, CNRS UMR 3681, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Wright, Matthew, E-mail: nicola.tamanini@cea.fr, E-mail: matthew.wright.13@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom)

    2016-04-01

    We investigate the cosmological dynamics of the recently proposed extended chameleon models at both background and linear perturbation levels. Dynamical systems techniques are employed to fully characterize the evolution of the universe at the largest distances, while structure formation is analysed at sub-horizon scales within the quasi-static approximation. The late time dynamical transition from dark matter to dark energy domination can be well described by almost all extended chameleon models considered, with no deviations from ΛCDM results at both background and perturbation levels. The results obtained in this work confirm the cosmological viability of extended chameleons as alternative dark energy models.

  20. The Higgs Portal and Cosmology

    Assamagan, Ketevi [Brookhaven National Lab. (BNL), Upton, NY (United States); Chen, Chien-Yi [Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Univ. of Victoria, BC (Canada); Chou, John Paul [Rutgers Univ., Piscataway, NJ (United States); Curtin, David [Univ. of Maryland, College Park, MD (United States); Fedderke, Michael A. [Univ. of Chicago, IL (United States); Gershtein, Yuri [Rutgers Univ., Piscataway, NJ (United States); He, Xiao-Gang [Shanghai Jiao Tong Univ. (China); Klute, Markus [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Kozaczuk, Jonathon [TRIUMF, Vancouver, BC (Canada); Kotwal, Ashutosh [Duke Univ., Durham, NC (United States); Lowette, Steven [Vrije Univ., Brussels (Belgium); No, Jose Miguel [Univ. of Sussex, Brighton (United Kingdom); Plehn, Tilman [Heidelberg Univ. (Germany); Qian, Jianming [Univ. of Michigan, Ann Arbor, MI (United States); Ramsey-Musolf, Michael [Univ. of Massachusetts, Amherst, MA (United States); Safonov, Alexei [Texas A & M Univ., College Station, TX (United States); Shelton, Jessie [Univ. of Illinois, Urbana-Champaign, IL (United States); Spannowsky, Michael [Durham Univ. (United Kingdom); Su, Shufang [Univ. of Arizona, Tucson, AZ (United States); Walker, Devin G. E. [Univ. of Washington, Seattle, WA (United States); Willocq, Stephane [Univ. of Massachusetts, Amherst, MA (United States); Winslow, Peter [Univ. of Massachusetts, Amherst, MA (United States)

    2016-04-18

    Higgs portal interactions provide a simple mechanism for addressing two open problems in cosmology: dark matter and the baryon asymmetry. In the latter instance, Higgs portal interactions may contain the ingredients for a strong first-order electroweak phase transition as well as new CP-violating interactions as needed for electroweak baryogenesis. These interactions may also allow for a viable dark matter candidate. We survey the opportunities for probing the Higgs portal as it relates to these questions in cosmology at the LHC and possible future colliders.

  1. Cosmology in the plasma universe

    Alfven, H.

    1987-05-01

    Space observations have opened the spectral regions of X-rays and γ-rays, which are produced by plasma processes. The Plasma Universe derived from observations in these regions is drastically different from the now generally accepted 'Visual Light Universe' based on visual light observations alone. Historically this transitions can be compared only to the transition from the geocentric to the heliocentric cosmology. The purpose of this paper is to discuss what criteria a cosmological theory must satisfy in order to be acceptable in the Plasma Universe. (author)

  2. Chandra Cluster Cosmology Project III: Cosmological Parameter Constraints

    Vikhlinin, A.; Kravtsov, A. V.; Burenin, R. A.

    2009-01-01

    function evolution to be used as a useful growth of a structure-based dark energy probe. In this paper, we present cosmological parameter constraints obtained from Chandra observations of 37 clusters with langzrang = 0.55 derived from 400 deg2 ROSAT serendipitous survey and 49 brightest z ≈ 0.05 clusters...

  3. Viscous cosmological models with a variable cosmological term ...

    Einstein's field equations for a Friedmann-Lamaitre Robertson-Walker universe filled with a dissipative fluid with a variable cosmological term L described by full Israel-Stewart theory are considered. General solutions to the field equations for the flat case have been obtained. The solution corresponds to the dust free model ...

  4. Constraints on cosmological parameters in power-law cosmology

    Rani, Sarita; Singh, J.K.; Altaibayeva, A.; Myrzakulov, R.; Shahalam, M.

    2015-01-01

    In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters H 0 (Hubble constant) and q (deceleration parameter). We investigate the constraints on these parameters using the latest 28 points of H(z) data and 580 points of Union2.1 compilation data and, compare the results with the results of ΛCDM . We also forecast constraints using a simulated data set for the future JDEM, supernovae survey. Our studies give better insight into power law cosmology than the earlier done analysis by Kumar [arXiv:1109.6924] indicating it tuning well with Union2.1 compilation data but not with H(z) data. However, the constraints obtained on and i.e. H 0 average and q average using the simulated data set for the future JDEM, supernovae survey are found to be inconsistent with the values obtained from the H(z) and Union2.1 compilation data. We also perform the statefinder analysis and find that the power-law cosmological models approach the standard ΛCDM model as q → −1. Finally, we observe that although the power law cosmology explains several prominent features of evolution of the Universe, it fails in details

  5. The Case for a Hierarchical Cosmology

    Vaucouleurs, G. de

    1970-01-01

    The development of modern theoretical cosmology is presented and some questionable assumptions of orthodox cosmology are pointed out. Suggests that recent observations indicate that hierarchical clustering is a basic factor in cosmology. The implications of hierarchical models of the universe are considered. Bibliography. (LC)

  6. A null test of the cosmological constant

    Chiba, Takeshi; Nakamura, Takashi

    2007-01-01

    We provide a consistency relation between cosmological observables in general relativity with the cosmological constant. Breaking of this relation at any redshift would imply the breakdown of the hypothesis of the cosmological constant as an explanation of the current acceleration of the universe. (author)

  7. The Universe Adventure - The Beginnings of Cosmology

    The Universe Adventure [ next ] [ home ] Go The Beginnings of Cosmology Since the beginning of of stars? What do the stars tell us about the future? Where did the Universe come from? Cosmology is will introduce you to Cosmology and the study of the structure, history, and fate of the Universe. In

  8. ["If Berger had survived the second world war - he certainly would have been a candidate for the Nobel Prize". Hans Berger and the legend of the Nobel Prize].

    Gerhard, U-J; Schönberg, A; Blanz, B

    2005-03-01

    The public opinion pays much attention to the Nobel Prize as an indicator for the scientific efficiency of a university or a country in connection with foundation of so-called elite universities. The former holder of the psychiatric chair in Jena and discoverer of the electroencephalogram Hans Berger (1873 - 1941) came into discussion as candidate for the Nobel Prize in physiology or medicine. The current medical-historical publications maintain the view that Berger should have received the Nobel Prize in 1936 as well as in 1949. This was prevented in 1936 by an enactment from Hitler, which forbid him to accept the prize, and later in 1949 by Berger's own death. According to documents of the Nobel archives these statements can be disproved. Berger was only nominated three times out of 65 nominations in 1940. Because of his death the other two recommendations in 1942 and 1947 were never evaluated.

  9. APS presents prizes in fluid dynamics and plasma physics

    Anon.

    1992-01-01

    This article reviews the presentation of the American Physical Society awards in fluid dynamics and plasma physics. The recipient of the plasma physics James Clerk Maxwell Prize was John M. Green for contributions to the theory of magnetohydrodynamics equilibria and ideal and resistive instabilities, for discovering the inverse scattering transform leading to soliton solutions of many nonlinear partial differential equations and for inventing the residue method of determining the transition to global chaos. The excellence in Plasma Physics Research Award was presented to Nathaniel A. Fisch for theoretical investigations of noninductive current generation in toroidally confined plasma. Wim Pieter Leemans received the Simon Ramo Award for experimental and simulational contributions to laser-plasma physics. William R. Sears was given the 1992 Fuid Dynamics Prize for contributions to the study of steady and unsteady aerodynamics, aeroacoustics, magnetoaerodynamics,and wind tunnel design. William C. Reynolds received the Otto Laporte Award for experimental, theoretical, and computational work in turbulence modeling and control and leadership in direct numerical simulation and large eddy simulation

  10. Editorial: The Sackler International Prize in Biophysical Sciences

    Frydman, Lucio

    2018-02-01

    The Raymond and Beverly Sackler International Prize is awarded alternatively in the fields of Biophysics, Chemistry and Physics on a yearly basis, by Tel Aviv University. The price is intended to encourage dedication to science, originality and excellence, by rewarding outstanding scientists under 45 years of age, with a total purse of 100,000. The 2016 Raymond and Beverly Sackler Prize was awarded in the field of Magnetic Resonance last February in a festive symposium, to three excellent researchers: Professor John Morton (University College London), Professor Guido Pintacuda (Ecole Normale Supérieure de Lyon and CNRS), and Professor Charalampos Kalodimos (at the time at the University of Minnesota). John was recognized for his novel contributions to quantum information processing, by means of a range of highly elegant physical phenomena involving both NMR and EPR. Guido was recognized for his methodological advances in solid state NMR spectroscopy, including advances in proton detection under ultrafast MAS at ultrahigh magnetic field, and for his insightful applications to challenging biological systems. While Charalampos (Babis) was recognized for beautifully detailed characterizations of structure, function, and dynamics in challenging and important biological systems through solution NMR spectroscopy.

  11. Eugene F. Fama: Nobel prize for 2013: Capital market efficiency

    Pantelić Svetlana

    2015-01-01

    Full Text Available In 2013 the Nobel Prize in Economic Sciences was awarded to the American economists, Eugene Fama, Lars Peter Hansen and Robert Shiller. The monetarists, Fama and Hansen, from the University of Chicago, and the Neo- Keynesian, Shiller, from the Yale University, according to the Swedish Royal Academy, won this prestigious prize for their research providing mathematical and economic models to determine (irregularities in the stock value trends at the stock exchanges. With his colleagues, in the 1960s Fama established that, in the short term, it is extremely difficult to forecast stock prices, given that new information gets embedded in the prices rather quickly. Shiller, however, determined that, although it is almost impossible to predict the stock prices for a period of few days, this is not true for a period of several years. He discovered that the stock prices fluctuate much more substantially than corporation dividents, and that the relationship between prices and dividends tends to decline when high, and to grow when low. This pattern does not apply only to stocks, but also to bonds and other forms of capital.

  12. Robert J. Shiller: Nobel prize for 2013: Capital market efficiency

    Pantelić Svetlana

    2015-01-01

    Full Text Available In 2013 the Nobel Prize in Economic Sciences was awarded to the American economists, Eugene Fama, Lars Peter Hansen and Robert Shiller. The monetarists, Fama and Hansen, from the University of Chicago, and the Neo- Keynesian, Shiller, from the Yale University, according to the Swedish Royal Academy, won this prestigious prize for their research providing mathematical and economic models to determine (irregularities in the stock value trends at the stock exchanges. With his colleagues, in the 1960s Fama established that, in the short term, it is extremely difficult to forecast stock prices, given that new information gets embedded in the prices rather quickly. Shiller, however, determined that, although it is almost impossible to predict the stock prices for a period of few days, this is not true for a period of several years. He discovered that the stock prices fluctuate much more substantially than corporation dividents, and that the relationship between prices and dividends tends to decline when high, and to grow when low. This pattern does not apply only to stocks, but also to bonds and other forms of capital.

  13. Soviet Union in the context of the Nobel prize

    Blokh, Abram M

    2018-01-01

    The result of meticulous research by Professor Abram Blokh, this book presents facts, documents, thoughts and comments on the system of the Nobel Prize awards to Russian and Soviet scientists. It provides a comprehensive overview of the relationship between the ideas expressed by the Nobel Foundation and those expressed by the autocratic and totalitarian regimes in Russia and the ex-Soviet Union during the 20th century who had the same attitude of revulsion toward the intellectual and humanistic values represented by the Nobel Prizes. To do his research, the author had access to the declassified documents in the archives of the Nobel Foundation for many years. Also included in the book are new materials obtained and developed by the author after the publication of the first two editions (in Russian). This additional information is from the archives of the Soviet Ministry of Foreign Affairs, the Russian Academy of Sciences, the Soviet Writers' Union et al. in Moscow and St Petersburg. These documents shed new...

  14. Monsef Benkirane awarded 2013 Ming K. Jeang Foundation Retrovirology Prize: landmark HIV-1 research honoured

    Berkhout, Ben; Lever, Andrew; Wainberg, Mark; Fassati, Ariberto; Borrow, Persephone; Fujii, Masahiro

    2013-01-01

    Dr. Monsef Benkirane, from the Laboratoire de Virologie Moleculaire in Montpellier, France, has been announced as the recipient of the 2013 Retrovirology Prize. This bi-annual prize covers all aspects of the Retrovirology field and celebrates groundbreaking research from retrovirologists aged

  15. Feelings of discomfort in Ōe's “Prize Stock”

    Thorsen Vilslev, Annette

    2017-01-01

    This article examines the feelings of discomfort in the works of Nobel Prize winner Kenzaburo Ōe. Focusing on Ōe's first short story “Prize Stock”, Shiiku (1957), the article discusses how the incredible event of a black pilot falling from the sky in the mountains near a small Japanese village...

  16. The young, not-so-young, and the 2007 Retrovirology Prize: call for nominations

    Jeang Kuan-Teh

    2007-09-01

    Full Text Available Abstract Recent findings suggest an aging scientific work force and an almost static publishing productivity in the United States. The Retrovirology Prize seeks to recognize and encourage the work of a mid-career retrovirologist between the ages of 45 and 60. The 2006 Retrovirology Prize was awarded to Dr. Joseph G. Sodroski.

  17. Prizes for innovation : Impact analysis in the ICT for Education sector

    P.A. Arora (Payal)

    2016-01-01

    textabstractThe use of prizes to stimulate innovation in education has dramatically increased in recent years, but, to date, no organization has attempted to critically examine the impact these prizes have had on education. This report attempts to fill this gap by conducting a landscape review of

  18. Brookhaven Lab physicist William Willis wins the 2003 W.K.H. Panofsky prize

    2003-01-01

    William Willis, a senior physicist Brookhaven National Laboratory, has won the American Physical Society's 2003 W.K.H. Panofsky Prize in Experimental Particle Physics. He received the prize, which consists of $5,000 and a certificate citing his contributions to physics, at the APS meeting in Philadelphia on April 6 (1 page).

  19. The History of Molecular Structure Determination Viewed through the Nobel Prizes.

    Jensen, William P.; Palenik, Gus J.; Suh, Il-Hwan

    2003-01-01

    Discusses the importance of complex molecular structures. Emphasizes their individual significance through examination of the Nobel Prizes of the 20th century. Highlights prizes awarded to Conrad Rontgen, Francis H.C. Crick, James D. Watson, Maurice H.F. Wilkins, and others. (SOE)

  20. A Nobel Prize for empirical macroeconometrics: assessing the contributions of Thomas Sargent and Christopher Sims

    Boumans, M.; Sent, E.M.

    2013-01-01

    This paper provides an assessment of the contributions of the 2011 Nobel Prize winners, Thomas Sargent and Christopher Sims. They received the prize ‘for their empirical research on cause and effect in the macroeconomy’. The paper illustrates that Sargent entertained different interpretations of