Global Fluctuation Spectra in Big Crunch/Big Bang String Vacua

Abstract

We study Big Crunch/Big Bang cosmologies that correspond to exact world-sheet superconformal field theories of type II strings. The string theory spacetime contains a Big Crunch and a Big Bang cosmology, as well as additional ``whisker'' asymptotic and intermediate regions. Within the context of free string theory, we compute, unambiguously, the scalar fluctuation spectrum in all regions of spacetime. Generically, the Big Crunch fluctuation spectrum is altered while passing through the bounce singularity. The change in the spectrum is characterized by a function $\Delta$, which is momentum and time-dependent. We compute $\Delta$ explicitly and demonstrate that it arises from the whisker regions. The whiskers are also shown to lead to ``entanglement'' entropy in the Big Bang region. Finally, in the Milne orbifold limit of our superconformal vacua, we show that $\Delta \to 1$ and, hence, the fluctuation spectrum is unaltered by the Big Crunch/Big Bang singularity. We comment on, but do not attempt to resolve, subtleties related to gravitational backreaction and light winding modes when interactions are taken into account.

arXiv comment68 pages, 1 figure; typos corrected

References in corpus (65)

• Heterotic and Type I String Dynamics from Eleven Dimensions
• Eleven-Dimensional Supergravity on a Manifold with Boundary
• Eternal Black Holes in AdS
• The Ekpyrotic Universe: Colliding Branes and the Origin of the Hot Big Bang
• The Pre-Big Bang Scenario in String Cosmology
• Cosmic Evolution in a Cyclic Universe
• The Universe as a Domain Wall
• From Big Crunch to Big Bang
• Quintessential inflation
• Heterotic M-theory in Five Dimensions
• Elements of String Cosmology
• On the Generation of a Scale-Invariant Spectrum of Adiabatic Fluctuations in Cosmological Models with a Contracting Phase
• Deflationary Universe Scenario
• A New Cosmological Scenario in String Theory
• Strings in a Time-Dependent Orbifold
• Density Perturbations in the Ekpyrotic Scenario
• On the Four-Dimensional Effective Action of Strongly Coupled Heterotic String Theory
• Inside the Horizon with AdS/CFT
• Strings in Time-Dependent Orbifolds
• Designing Cyclic Universe Models
• Instability of Spacelike and Null Orbifold Singularities
• The primordial curvature perturbation in the ekpyrotic Universe
• A Resolution of the Cosmological Singularity with Orientifolds
• On the Spectrum of Fluctuations in an Effective Field Theory of the Ekpyrotic Universe
• From Big Bang to Big Crunch and Beyond
• Cosmological Perturbations in a Big Crunch/Big Bang Space-time
• Solvable model of strings in a time-dependent plane-wave background
• Conformally Exact Metric and Dilaton in String Theory on Curved Spacetime
• The geometry of null rotation identifications
• A Space-Time Orbifold: A Toy Model for a Cosmological Singularity
• String Propagation in the Presence of Cosmological Singularities
• On the instability of 3d null singularities
• Cosmological structure problem of the ekpyrotic scenario
• Conditions for Generating Scale-Invariant Density Perturbations
• On Smooth Time-Dependent Orbifolds and Null Singularities
• Holography and String Dynamics in Time-dependent Backgrounds
• Cosmological String Backgrounds from Gauged WZW Models
• Inflation versus Cyclic Predictions for Spectral Tilt
• Comments on Cosmological Singularities in String Theory
• Quantum Fields in a Big Crunch/Big Bang Spacetime
• Strings in the Extended BTZ Spacetime
• Exciting AdS Orbifolds
• Bouncing Brane Cosmologies from Warped String Compactifications
• Cosmological perturbations and the transition from contraction to expansion
• NCOS and D-branes in Time-dependent Backgrounds
• On Time-dependent Backgrounds in Supergravity and String Theory
• Global Analysis of New Gravitational Singularities in String and Particle Theories
• Visible Branes with Negative Tension in Heterotic M-Theory
• Holography beyond the horizon and cosmic censorship
• Null orbifolds in AdS, Time Dependence and Holography
• From Big Crunch To Big Bang - Is It Possible?
• Null Brane Intersections
• Removing Singularities
• Exact Bosonic and Supersymmetric String Black Hole Solutions
• Strings in Singular Time-Dependent Backgrounds
• On the Classical Stability of Orientifold Cosmologies
• Branes in Time-Dependent Backgrounds and AdS/CFT Correspondence
• Strings in an electric field, and the Milne Universe
• D-Branes on the Null-Brane
• The Challenging Cosmic Singularity
• Plane waves with weak singularities
• Open strings in relativistic ion traps
• Is Vacuum Decay Significant in Ekpyrotic and Cyclic Models?
• Massless BTZ black holes in minisuperspace
• Cosmological String Backgrounds

Cited by in corpus (26)

• Ekpyrotic and Cyclic Cosmology
• New Ekpyrotic Cosmology
• Brane World Cosmology
• A Matrix Big Bang
• The cosmic gravitational wave background in a cyclic universe
• Conditions for Generating Scale-Invariant Density Perturbations
• The Cyclic Model Simplified
• Supersymmetric Galileons
• Supersymmetric P(X,phi) and the Ghost Condensate
• DBI Realizations of the Pseudo-Conformal Universe and Galilean Genesis Scenarios
• The Pseudo-Conformal Universe: Scale Invariance from Spontaneous Breaking of Conformal Symmetry
• On the Initial Conditions in New Ekpyrotic Cosmology
• A new duality relating density perturbations in expanding and contracting Friedmann cosmologies
• Effective Dynamics of the Matrix Big Bang
• Non-linear Realizations of Conformal Symmetry and Effective Field Theory for the Pseudo-Conformal Universe
• Shift Symmetry and Inflation in Supergravity
• From Satisfying to Violating the Null Energy Condition
• Closed Strings in Misner Space: Cosmological Production of Winding Strings
• Big Bang Models in String Theory
• Cosmic Perturbations Through the Cyclic Ages
• A Matrix Model for the Null-Brane
• Perturbations in a Bouncing Brane Model
• Scale Invariance via a Phase of Slow Expansion
• Flow of Geometries and Instantons on the Null Orbifold
• Strong Coupling Problem with Time-Varying Sound Speed
• Matrix Quantum Mechanics on $S^1/{\mathbb{Z}}_2$