Rejuvenating the Hope of a Swampland Consistent Inflated
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Inflation, Large Branes, and the Shape of Space
Inflation, Large Branes, and the Shape of Space Brett McInnes National University of Singapore email: [email protected] ABSTRACT Linde has recently argued that compact flat or negatively curved spatial sections should, in many circumstances, be considered typical in Inflationary cosmologies. We suggest that the “large brane instability” of Seiberg and Witten eliminates the negative candidates in the context of string theory. That leaves the flat, compact, three-dimensional manifolds — Conway’s platycosms. We show that deep theorems of Schoen, Yau, Gromov and Lawson imply that, even in this case, Seiberg-Witten instability can be avoided only with difficulty. Using a specific cosmological model of the Maldacena-Maoz type, we explain how to do this, and we also show how the list of platycosmic candidates can be reduced to three. This leads to an extension of the basic idea: the conformal compactification of the entire Euclidean spacetime also has the topology of a flat, compact, four-dimensional space. arXiv:hep-th/0410115v2 19 Oct 2004 1. Nearly Flat or Really Flat? Linde has recently argued [1] that, at least in some circumstances, we should regard cosmological models with flat or negatively curved compact spatial sections as the norm from an Inflationary point of view. Here we wish to argue that cosmic holography, in the novel form proposed by Maldacena and Maoz [2], gives a deep new interpretation of this idea, and also sharpens it very considerably to exclude the negative case. This focuses our attention on cosmological models with flat, compact spatial sections. Current observations [3] show that the spatial sections of our Universe [as defined by observers for whom local isotropy obtains] are fairly close to being flat: the total density parameter Ω satisfies Ω = 1.02 0.02 at 95% confidence level, if we allow the imposition ± of a reasonable prior [4] on the Hubble parameter. -
Anomalies, Dualities, and Topology of D = 6 N = 1 Superstring Vacua
RU-96-16 NSF-ITP-96-21 CALT-68-2057 IASSNS-HEP-96/53 hep-th/9605184 Anomalies, Dualities, and Topology of D =6 N =1 Superstring Vacua Micha Berkooz,1 Robert G. Leigh,1 Joseph Polchinski,2 John H. Schwarz,3 Nathan Seiberg,1 and Edward Witten4 1Department of Physics, Rutgers University, Piscataway, NJ 08855-0849 2Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030 3California Institute of Technology, Pasadena, CA 91125 4Institute for Advanced Study, Princeton, NJ 08540 Abstract We consider various aspects of compactifications of the Type I/heterotic Spin(32)/Z2 theory on K3. One family of such compactifications in- cludes the standard embedding of the spin connection in the gauge group, and is on the same moduli space as the compactification of arXiv:hep-th/9605184v1 25 May 1996 the heterotic E8 × E8 theory on K3 with instanton numbers (8,16). Another class, which includes an orbifold of the Type I theory re- cently constructed by Gimon and Polchinski and whose field theory limit involves some topological novelties, is on the moduli space of the heterotic E8 × E8 theory on K3 with instanton numbers (12,12). These connections between Spin(32)/Z2 and E8 × E8 models can be demonstrated by T duality, and permit a better understanding of non- perturbative gauge fields in the (12,12) model. In the transformation between Spin(32)/Z2 and E8 × E8 models, the strong/weak coupling duality of the (12,12) E8 × E8 model is mapped to T duality in the Type I theory. The gauge and gravitational anomalies in the Type I theory are canceled by an extension of the Green-Schwarz mechanism. -
Eternal Inflation and Its Implications
IOP PUBLISHING JOURNAL OF PHYSICS A: MATHEMATICAL AND THEORETICAL J. Phys. A: Math. Theor. 40 (2007) 6811–6826 doi:10.1088/1751-8113/40/25/S25 Eternal inflation and its implications Alan H Guth Center for Theoretical Physics, Laboratory for Nuclear Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA E-mail: [email protected] Received 8 February 2006 Published 6 June 2007 Online at stacks.iop.org/JPhysA/40/6811 Abstract Isummarizetheargumentsthatstronglysuggestthatouruniverseisthe product of inflation. The mechanisms that lead to eternal inflation in both new and chaotic models are described. Although the infinity of pocket universes produced by eternal inflation are unobservable, it is argued that eternal inflation has real consequences in terms of the way that predictions are extracted from theoretical models. The ambiguities in defining probabilities in eternally inflating spacetimes are reviewed, with emphasis on the youngness paradox that results from a synchronous gauge regularization technique. Although inflation is generically eternal into the future, it is not eternal into the past: it can be proven under reasonable assumptions that the inflating region must be incomplete in past directions, so some physics other than inflation is needed to describe the past boundary of the inflating region. PACS numbers: 98.80.cQ, 98.80.Bp, 98.80.Es 1. Introduction: the successes of inflation Since the proposal of the inflationary model some 25 years ago [1–4], inflation has been remarkably successful in explaining many important qualitative and quantitative properties of the universe. In this paper, I will summarize the key successes, and then discuss a number of issues associated with the eternal nature of inflation. -
A Correspondence Between Strings in the Hagedorn Phase and Asymptotically De Sitter Space
A correspondence between strings in the Hagedorn phase and asymptotically de Sitter space Ram Brustein(1), A.J.M. Medved(2;3) (1) Department of Physics, Ben-Gurion University, Beer-Sheva 84105, Israel (2) Department of Physics & Electronics, Rhodes University, Grahamstown 6140, South Africa (3) National Institute for Theoretical Physics (NITheP), Western Cape 7602, South Africa [email protected], [email protected] Abstract A correspondence between closed strings in their high-temperature Hage- dorn phase and asymptotically de Sitter (dS) space is established. We identify a thermal, conformal field theory (CFT) whose partition function is, on the one hand, equal to the partition function of closed, interacting, fundamental strings in their Hagedorn phase yet is, on the other hand, also equal to the Hartle-Hawking (HH) wavefunction of an asymptotically dS Universe. The Lagrangian of the CFT is a functional of a single scalar field, the condensate of a thermal scalar, which is proportional to the entropy density of the strings. The correspondence has some aspects in common with the anti-de Sitter/CFT correspondence, as well as with some of its proposed analytic continuations to a dS/CFT correspondence, but it also has some important conceptual and technical differences. The equilibrium state of the CFT is one of maximal pres- sure and entropy, and it is at a temperature that is above but parametrically close to the Hagedorn temperature. The CFT is valid beyond the regime of semiclassical gravity and thus defines the initial quantum state of the dS Uni- verse in a way that replaces and supersedes the HH wavefunction. -
Punctuated Eternal Inflation Via Ads/CFT
BROWN-HET-1593 Punctuated eternal inflation via AdS/CFT David A. Lowe† and Shubho Roy†♮♯∗ †Department of Physics, Brown University, Providence, RI 02912, USA ♮Physics Department City College of the CUNY New York, NY 10031, USA and ♯Department of Physics and Astronomy Lehman College of the CUNY Bronx, NY 10468, USA Abstract The work is an attempt to model a scenario of inflation in the framework of Anti de Sit- ter/Conformal Field theory (AdS/CFT) duality, a potentially complete nonperturbative description of quantum gravity via string theory. We look at bubble geometries with de Sitter interiors within an ambient Schwarzschild anti-de Sitter black hole spacetime and obtain a characterization for the states in the dual CFT on boundary of the asymptotic AdS which code the expanding dS bubble. These can then in turn be used to specify initial conditions for cosmology. Our scenario naturally interprets the entropy of de Sitter space as a (logarithm of) subspace of states of the black hole microstates. Consistency checks are performed and a number of implications regarding cosmology are discussed including how the key problems or paradoxes of conventional eternal inflation are overcome. arXiv:1004.1402v1 [hep-th] 8 Apr 2010 ∗Electronic address: [email protected], [email protected] 1 I. INTRODUCTION Making contact with realistic cosmology remains the fundamental challenge for any can- didate unified theory of matter and gravity. Precise observations [1, 2] indicate that the current epoch of the acceleration of universe is driven by a very mild (in Planck units) neg- ative pressure, positive energy density constituent - “dark energy”. -
Yasunori Nomura
Yasunori Nomura UC Berkeley; LBNL Why is the universe as we see today? ― Mathematics requires — “We require” Dramatic change of the view Our universe is only a part of the “multiverse” … suggested both from observation and theory This comes with revolutionary change of the view on spacetime and gravity • Holographic principle • Horizon complementarity • Multiverse as quantum many worlds • … … implications on particle physics and cosmology Shocking news in 1998 Supernova cosmology project; Supernova search team Universe is accelerating! ≠ 0 ! Particle Data Group (2010) 2 2 4 4 … natural size of ≡ MPl (naively) ~ MPl (at the very least ~ TeV ) Observationally, -3 4 120 ~ (10 eV) Naïve estimates O(10 ) too large Also, ~ matter — Why now? Nonzero value completely changes the view ! 4 Natural size for vacuum energy ~ MPl 4 • 4 -MPl 0 -120 4 MPl ,obs ~10 MPl Unnatural (Note: = 0 is NOT special from theoretical point of view) Wait! Is it really unnatural to observe this value? • No observer0 No observer It is quite “natural” to observe ,obs, as long as different values of are “sampled” Weinberg (’87) Many universes ─ multiverse ─ needed • String landscape Compact (six) dimensins ex. O(100) fields with O(10) minima each → huge number of vacua → O(10100) vacua • Eternal inflation Inflation is (generically) future eternal → populate all the vacua Anthropic considerations mandatory (not an option) Full of “miracles” Examples: • yu,d,e v ~ QCD ~ O(0.01) QCD … otherwise, no nuclear physics or chemistry (Conservative) estimate of the probability: P « 10-3 • Baryon ~ DM …. Some of them anthropic (and some may not) Implications? • Observational / experimental (test, new scenarios, …) • Fundamental physics (spacetime, gravity, …) Full of “miracles” Examples: • yu,d,e v ~ QCD ~ O(0.01) QCD … otherwise, no nuclear physics or chemistry (Conservative) estimate of the probability: P « 10-3 • Baryon ~ DM …. -
Some Comments on Physical Mathematics
Preprint typeset in JHEP style - HYPER VERSION Some Comments on Physical Mathematics Gregory W. Moore Abstract: These are some thoughts that accompany a talk delivered at the APS Savannah meeting, April 5, 2014. I have serious doubts about whether I deserve to be awarded the 2014 Heineman Prize. Nevertheless, I thank the APS and the selection committee for their recognition of the work I have been involved in, as well as the Heineman Foundation for its continued support of Mathematical Physics. Above all, I thank my many excellent collaborators and teachers for making possible my participation in some very rewarding scientific research. 1 I have been asked to give a talk in this prize session, and so I will use the occasion to say a few words about Mathematical Physics, and its relation to the sub-discipline of Physical Mathematics. I will also comment on how some of the work mentioned in the citation illuminates this emergent field. I will begin by framing the remarks in a much broader historical and philosophical context. I hasten to add that I am neither a historian nor a philosopher of science, as will become immediately obvious to any expert, but my impression is that if we look back to the modern era of science then major figures such as Galileo, Kepler, Leibniz, and New- ton were neither physicists nor mathematicans. Rather they were Natural Philosophers. Even around the turn of the 19th century the same could still be said of Bernoulli, Euler, Lagrange, and Hamilton. But a real divide between Mathematics and Physics began to open up in the 19th century. -
2005 March Meeting Gears up for Showtime in the City of Angels
NEWS See Pullout Insert Inside March 2005 Volume 14, No. 3 A Publication of The American Physical Society http://www.aps.org/apsnews 2005 March Meeting Gears Up for Reborn Nicholson Medal Showtime in the City of Angels Stresses Mentorship Established in memory of Dwight The latest research relevance to the design R. Nicholson of the University of results on the spin Hall and creation of next- Iowa, who died tragically in 1991, effect, new chemistry generation nano-electro- and first given in 1994, the APS with superatoms, and mechanical systems Nicholson Medal has been reborn several sessions cel- (NEMS). Moses Chan this year as an award for human ebrating all things (Pennsylvania State Uni- outreach. According to the infor- Einstein are among the versity) will talk about mation contained on the Medal’s expected highlights at evidence of Bose-Einstein web site (http://www.aps.org/praw/ the 2005 APS March condensation in solid he- nicholso/index.cfm), the Nicholson meeting, to be held later lium, while Stanford Medal for Human Outreach shall Photo Credit: Courtesy of the Los Angeles Convention Center this month in Los University’s Zhixun Shen be awarded to a physicist who ei- Angeles, California. The will discuss how photo- ther through teaching, research, or Photo from Iowa University Relations. conference is the largest physics Boltzmann, and Ehrenfest, but also emission spectroscopy has science-related activities, Dwight R. Nicholson. meeting of the year, featuring some Emmy Noether, one of the rare emerged as a leading tool to push -
Primordial Power Spectra from an Emergent Universe: Basic Results and Clarifications
universe Article Primordial Power Spectra from an Emergent Universe: Basic Results and Clarifications Killian Martineau and Aurélien Barrau * Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes, CNRS/IN2P3 53, avenue des Martyrs, 38026 Grenoble CEDEX, France; [email protected] * Correspondence: [email protected] Received: 30 November 2018; Accepted: 15 December 2018; Published: 18 December 2018 Abstract: Emergent cosmological models, together with the Big Bang and bouncing scenarios, are among the possible descriptions of the early Universe. This work aims at clarifying some general features of the primordial tensor power spectrum in this specific framework. In particular, some naive beliefs are corrected. Using a toy model, we investigate the conditions required to produce a scale-invariant spectrum and show to what extent this spectrum can exhibit local features sensitive to the details of the scale factor evolution near the transition time. Keywords: Emergent universe; quantum cosmology; primordial tensor spectrum 1. Introduction The term “Big Bang” is somewhat ambiguous. In a sense, it just refers to the expansion of space and to the fact that the entire observable universe was, in the past, much smaller, denser, and hotter. This is obviously non-controversial. In another sense, it refers to the initial singularity in and of itself. In this stronger meaning, the very idea of the Big Bang is far from obvious. It is a generic prediction of general relativity (GR)—remaining usually true in the inflationary paradigm [1,2]—which can, however, be violated in some circumstances. The first important class of models without a Big Bang (in the strong sense) are bouncing models. -
Is String Theory Holographic? 1 Introduction
Holography and large-N Dualities Is String Theory Holographic? Lukas Hahn 1 Introduction1 2 Classical Strings and Black Holes2 3 The Strominger-Vafa Construction3 3.1 AdS/CFT for the D1/D5 System......................3 3.2 The Instanton Moduli Space.........................6 3.3 The Elliptic Genus.............................. 10 1 Introduction The holographic principle [1] is based on the idea that there is a limit on information content of spacetime regions. For a given volume V bounded by an area A, the state of maximal entropy corresponds to the largest black hole that can fit inside V . This entropy bound is specified by the Bekenstein-Hawking entropy A S ≤ S = (1.1) BH 4G and the goings-on in the relevant spacetime region are encoded on "holographic screens". The aim of these notes is to discuss one of the many aspects of the question in the title, namely: "Is this feature of the holographic principle realized in string theory (and if so, how)?". In order to adress this question we start with an heuristic account of how string like objects are related to black holes and how to compare their entropies. This second section is exclusively based on [2] and will lead to a key insight, the need to consider BPS states, which allows for a more precise treatment. The most fully understood example is 1 a bound state of D-branes that appeared in the original article on the topic [3]. The third section is an attempt to review this construction from a point of view that highlights the role of AdS/CFT [4,5]. -
Hawking Radiation and Black Hole Thermodynamics
HAWKING RADIATION AND BLACK HOLE THERMODYNAMICS ∗ Don N. Page † Institute for Theoretical Physics Department of Physics, University of Alberta Edmonton, Alberta, Canada T6G 2J1 (2004 September 3; additional section added 2004 December 31 ‡) Abstract An inexhaustive review of Hawking radiation and black hole thermody- namics is given, focusing especially upon some of the historical aspects as seen from the biased viewpoint of a minor player in the field on and off for the past thirty years. arXiv:hep-th/0409024v3 31 Dec 2004 ∗Alberta-Thy-18-04, hep-th/0409024, review article solicited for a celebratory Focus Issue on Relativity, “Spacetime 100 Years Later,” to be published in New Journal of Physics. †Internet address: [email protected] ‡On this date the author reached an age which is an integer divisor of the number of references. 1 1 Historical Background Black holes are perhaps the most perfectly thermal objects in the universe, and yet their thermal properties are not fully understood. They are described very accurately by a small number of macroscopic parameters (e.g., mass, angular mo- mentum, and charge), but the microscopic degrees of freedom that lead to their thermal behavior have not yet been adequately identified. Strong hints of the thermal properties of black holes came from the behavior of their macroscopic properties that were formalized in the (classical) four laws of black hole mechanics [1], which have analogues in the corresponding four laws of thermodynamics: The zeroth law of black hole mechanics is that the surface gravity κ of a stationary black hole is constant over its event horizon [2, 1]. -
The University of Tokyo's Newly Founded Institute for the Physics
hosted by IPMU was held on 17 - 21 with new projects. The success of the News December 2007. The workshop,“ Focus workshop also clarified the importance Week on LHC Phenomenology”, was of follow-up visitor programs, such as organized by Mihoko Nojiri (PI of IPMU) one month stays to finalize the projects and held at the IPMU, Research Center started in this meeting.” Building, on the Kashiwa campus. Many theorists found the discussion The Large Hadron Collider (LHC) at with experimentalists extremely CERN in Switzerland will start operating important, and vice verse.“ We in 2008. The aim of the meeting was to developed a consensus that it is bring together leading experimentalists important to set a series of workshops and phenomenologists working on LHC, to understand phenomena at the LHC to come up with new idea on physics and to maximize the performance of beyond the standard model. To reach the new physics searches,”remarked Launch of IPMU this goal, it is necessary to understand Nojiri. The University of Tokyo’s newly phenomena in the standard model: founded Institute for the Physics and deep theoretical understanding of the Mathematics of the Universe (IPMU) , standard model, and thus processes was launched on October 1, 2007. and responses involved in the LHC IPMU has been approved as one of the experiments, is essential to identify World Premier International Research effects of the new physics in the Center Initiatives (WPI) of the Ministry experiments. of Education, Culture, Sports, Science The following invited speakers with a and Technology (MEXT). IPMU is an range of expertise were invited.