MEASURES OF THE MULTIVERSE Alex Vilenkin Tufts Institute of Cosmology Stanford, March 2008.

Slides:

Advertisements

Similar presentations

Alex Vilenkin Tufts Institute of Cosmology Tokyo, November 2008 HOLOGRAPHIC MEASURE OF THE MULTIVERSE.

Advertisements

MEASURES OF THE MULTIVERSE Alex Vilenkin Tufts Institute of Cosmology Cambridge, Dec

Andrei Linde Andrei Linde. Contents: From the Big Bang theory to Inflationary Cosmology Eternal inflation, multiverse, string theory landscape, anthropic.

Preheating after N-flation Shinsuke Kawai (Helsinki Institute of Physics, University of Helsinki) PRD77(2008) [arXiv:0803:0321] with D. Battefeld.

A theorist’s view of dark energy Andreas Albrecht (UC Davis) UCSC Colloquium Jan

Topological Phases of Eternal Inflation Yasuhiro Sekino （ Okayama Institute for Quantum Physics) w/ Stephen Shenker (Stanford), Leonard Susskind (Stanford),

Cosmology and extragalactic astronomy Mat Page Mullard Space Science Lab, UCL 10. Inflation.

Evolutionary effects in one-bubble open inflation for string landscape Daisuke YAMAUCHI Yukawa Institute for Theoretical Physics,

Cosmological Structure Formation A Short Course

Conceptual Issues in Inflation. New Inflation V

Probing the Structure of Stringy Landscape by Large Scale CMB Experiments Amjad Ashoorioon in collaboration with Ulf H. Danielsson 24 th Nordic Conference.

Quintessence – Phenomenology. How can quintessence be distinguished from a cosmological constant ?

Eternal Inflation and Sinks in the Landscape Andrei Linde Andrei Linde.

InflationInflation Andrei Linde Lecture 1. Plan of the lectures: Inflation: a general outlook Basic inflationary models (new inflation, chaotic inflation,

Large Scale Structure of the Universe. Evolution of the LSS – a brief history Picture credit: A. Kravtsov,

The Theory/Observation connection lecture 3 the (non-linear) growth of structure Will Percival The University of Portsmouth.

FRW/CFT duality: A holographic framework for eternal inflation Yasuhiro Sekino (KEK) Based on collaborations with: L. Susskind (Stanford), S. Shenker (Stanford),

Chaplygin gas in decelerating DGP gravity Matts Roos University of Helsinki Department of Physics and and Department of Astronomy 43rd Rencontres de Moriond,

1 Multi-field Open Inflation ＆ Instanton YITP, Kyoto University Kazuyuki Sugimura (Collaborator : D. Yamauchi and M. Sasaki)

Galaxy bias with Gaussian/non- Gaussian initial condition: a pedagogical introduction Donghui Jeong Texas Cosmology Center The University of Texas at Austin.

Emergent Universe Scenario

Cosmology: The Study of the Universe as a Whole Physics 360 Geol 360 Astronomy John Swez.

THE LARGE SCALE CMB CUT-OFF AND THE TENSOR-TO-SCALAR RATIO Gavin Nicholson Imperial College London with Carlo Contaldi Imperial College London (astro-ph/ )

Coslab 2006 lorentz center cosmological evolution of cosmic string loops mairi sakellariadou king’s college london astro-ph/ in collaboration with.

Portsmouth. Models of inflation and primordial perturbations David Wands Institute of Cosmology and Gravitation University of Portsmouth Cosmo – 02Chicago,

Probing the Reheating with Astrophysical Observations Jérôme Martin Institut d’Astrophysique de Paris (IAP) 1 [In collaboration with K. Jedamzik & M. Lemoine,

Les Houches Lectures on Cosmic Inflation Four Parts 1)Introductory material 2)Entropy, Tuning and Equilibrium in Cosmology 3)Classical and quantum probabilities.

We don’t know, all previous history has been wiped out Assume radiation dominated era We have unified three of the forces: Strong, Electromagnetic, and.

What can we learn from galaxy clustering? David Weinberg, Ohio State University Berlind & Weinberg 2002, ApJ, 575, 587 Zheng, Tinker, Weinberg, & Berlind.

Landscape, anthropic arguments and dark energy Jaume Garriga (U. Barcelona)

Frédéric Henry-Couannier CPPM/RENOIR Marseille The Dark Side of Gravity and our Universe.

30 YEARS OF COSMIC STRINGS Alex Vilenkin Tufts Institute of Cosmology.

Open Inflation in the Landscape Misao Sasaki (YITP, Kyoto University) in collaboration with Daisuke Yamauchi (now at ICRR, U Tokyo) and Andrei Linde, Atsushi.

Clustering in the Sloan Digital Sky Survey Bob Nichol (ICG, Portsmouth) Many SDSS Colleagues.

Inflation Without a Beginning

Topological Phases of Eternal Inflation

Detecting or Falsifying the Multiverse David Spergel Daan Meerburg.

Our Evolving Universe1 Vital Statistics of the Universe Today… l l Observational evidence for the Big Bang l l Vital statistics of the Universe   Hubble’s.

PROBABILITIES IN THE LANDSCAPE Alex Vilenkin Tufts Institute of Cosmology.

The Theory/Observation connection lecture 2 perturbations Will Percival The University of Portsmouth.

Andrei Linde. 1.Why inflationary multiverse? 1.Various measures 2.Counting worlds and minds.

Review Quiz No. 28 :60 1.all objects and structures in the Universe (including galaxy clusters and galaxies) expanding. 2.all objects and structures in.

The Fate of the Universe

Inflation and String Cosmology Andrei Linde Andrei Linde.

Inflation and Stringy Landscape Andrei Linde. New Inflation V.

Dark Energy Expanding Universe Accelerating Universe Dark Energy Scott Dodelson March 7, 2004.

SUNYAEV-ZELDOVICH EFFECT. OUTLINE  What is SZE  What Can we learn from SZE  SZE Cluster Surveys  Experimental Issues  SZ Surveys are coming: What.

Alex Vilenkin (Tufts University) Miami, December 2014 TOPOLOGICAL DEFECTS FROM THE MULTIVERSE.

Les Houches Lectures on Cosmic Inflation Four Parts 1)Introductory material 2)Entropy, Tuning and Equilibrium in Cosmology 3)Classical and quantum probabilities.

Multiverse from a particle physicist’s perspective Taizan Watari (Univ. of Tokyo) KEK PH07 Mar review + ph/ th/ (w/ B. Feldstein.

Michael Doran Institute for Theoretical Physics Universität Heidelberg Time Evolution of Dark Energy (if any …)

PHY th century cosmology 1920s – 1990s (from Friedmann to Freedman)  theoretical technology available, but no data  20 th century: birth of observational.

Using Baryon Acoustic Oscillations to test Dark Energy Will Percival The University of Portsmouth (including work as part of 2dFGRS and SDSS collaborations)

General Relativity Physics Honours 2008 A/Prof. Geraint F. Lewis Rm 560, A29 Lecture Notes 10.

Inflation, infinity, equilibrium and the observable Universe Andreas Albrecht UC Davis KIPAC Seminar Jan A. Stanford Jan

Modeling the dependence of galaxy clustering on stellar mass and SEDs Lan Wang Collaborators: Guinevere Kauffmann (MPA) Cheng Li (MPA/SHAO, USTC) Gabriella.

Inflation Sean Carroll, Caltech SSI The state of the universe appears finely-tuned 2.Inflation can make things smooth and flat 3.Primordial perturbations.

Physics in the Universe Created by Bubble Nucleation Yasuhiro Sekino (Okayama Institute for Quantum Physics) Collaboration with Ben Freivogel (UC Berkeley),

Holographic Dark Energy and Anthropic Principle Qing-Guo Huang Interdisciplinary Center of Theoretical Studies CAS

Cosmological Constant in the Multiverse Vladimir Burdyuzha Astro-Space Center, Lebedev Physical Institute, Russian Academy of Sciences, Moscow Miami-2008,

Dark Energy in the Early Universe Joel Weller arXiv:gr-qc/

Feasibility of detecting dark energy using bispectrum Yipeng Jing Shanghai Astronomical Observatory Hong Guo and YPJ, in preparation.

KASI Galaxy Evolution Journal Club A Massive Protocluster of Galaxies at a Redshift of z ~ P. L. Capak et al. 2011, Nature, in press (arXive: )

Probing Dark Energy with Cosmological Observations Fan, Zuhui ( 范祖辉 ) Dept. of Astronomy Peking University.

Cosmology Scale factor Cosmology à la Newton Cosmology à la Einstein

Dark Energy: Hopes and Expectations Mario Livio Space Telescope Science Institute Mario Livio Space Telescope Science Institute.

The prolate shape of the Galactic halo Amina Helmi Kapteyn Astronomical Institute.

Sam Young University of Sussex arXiv: , SY, Christian Byrnes Texas Symposium, 16 th December 2015 CONDITIONS FOR THE FORMATION OF PRIMORDIAL BLACK.

Inflation, Stringy Landscape and Anthropic Principle.

Collapse of Small Scales Density Perturbations

Presentation transcript:

MEASURES OF THE MULTIVERSE Alex Vilenkin Tufts Institute of Cosmology Stanford, March 2008

Salute to Andrei !

The measure problem i+i+ Bubbles (pocket universes) We want to find P j – probability for a randomly picked observer to be in a bubble of type j. The number of bubbles & the number of observers per bubble are infinite. Need a cutoff. Results are strongly cutoff-dependent.

Measure proposals Global time cutoff Garcia-Bellido, Linde & Linde (1994) Linde, Linde & Mezhlumian (1994) Pocket-based Garriga, Schwartz-Perlov, A.V. & Winitzki (2005) Easther, Lim & Martin (2005) Adjustable cutoff Linde (2007) Causal-patch Bousso (2006), Susskind (2007) We are in the process of working out the properties of different measures and their observational predictions.

THIS TALK: Scale-factor cutoff measure Predictions for. Contrast with pocket-based measure Based on work with Alan Guth, Andrea de Simone & Michael Salem. Work in progress…

t = const steady-state evolution. The distribution does not depend on the initial state (but depends on what we use as t). Garcia-Bellido, Linde & Linde (1994) Linde, Linde & Mezhlumian (1994) Linde (2007) Global time cutoff Possible choices of t : (i) proper time along geodesics orthogonal to ; (ii) scale-factor time,.

Volume in regions of any kind grows as Linde & Mezhlumian (1996), Guth (2001), Tegmark (2004), Bousso, Freivogel & Yang (2007) Observers who take less time to evolve are rewarded by a huge volume factor. Observers who evolve faster than us by and measure are more numerous by Driven by fastest- expanding vacuum Proper-time cutoff is ruled out. Proper time cutoff leads to “youngness paradox”

Scale-factor cutoff – a mild youngness bias Growth of volume: – decay rate of the slowest-decaying vacuum The probability of living at T = 2.9K is enhanced only by. Not ruled out and has interesting observational consequences.

Pocket-based measure – bubble abundance, Garriga, Schwartz-Perlov, A.V. & Winitzki (2005) Easther, Lim & Martin (2005) – weight factor. Sample equal comoving volumes in all bubbles (all bubble spacetimes are identical at early times). Slow-roll expansion inside the bubble Note: large inflation inside bubbles is rewarded. Similar Z-dependence for Linde’s adjustable cutoff.

Predictions for : Depend on the slow-roll expansion factor Z in the bubbles. Pocket-based measure favors large inflation: Scale-factor cutoff does not: (unless large Z are strongly suppressed in the landscape) Detectable negative curvature is feasible. Freivogel, Kleban, Martinez & Susskind (2006)

Predictions for : “Q catastrophe” Feldstein, Hall & Watari (2005) Garriga & A.V. (2006) Depend on the shape of inflaton potential. Pocket-based measure: – exponential Q-dependence Scale-factor cutoff: Mild Z-dependence no Q-catastrophe. The exact form of P(Q) is model-dependent.

Distribution for : standard approach A.V. (1995), Efstathiou (1995), Martel, Shapiro & Weinberg (1998). Assume in the range of interest. Assume asymptotic fraction of matter clustered in large galaxies ( ). Weinberg (1987), Linde (1987),. All constants other than are fixed. Appropriate for pocket-based measure

Distribution for : scale-factor cutoff Suppose observers do their measurements of at a fixed proper time after galactic halo collapse. (Allowing for chemical and biological evolution.) fraction of matter clustered in large galaxies 5 Gyr prior to the cutoff. Volume thermalized in scale factor interval da (reflects youngness bias). Proper time corresponding to scale factor change (a c /a). Cutoff at. Press-Schechter Warren et. al.

Once dominates, expansion accelerates, triggering scale-factor cutoff. Large values of are suppressed. De Simone, Guth, Salem & A.V. (2008).

Varying M and.

Including negative (A) Count all halos formed more than 5 Gyr before the big crunch. (B) Count all halos formed more than 5 Gyr before turnaround.

CONCLUSIONS Scale-factor cutoff is a promising measure proposal. Prediction for is a good fit to the data. No Q-catastrophe. Possibility of a detectable curvature. No “Boltzmann brain” problem. (Assuming that the slowest-decaying vacuum does not support BBs)