String Propagation through a Big Crunch/Big Bang Transition

Abstract

We consider the propagation of classical and quantum strings on cosmological space-times which interpolate from a collapsing phase to an expanding phase. We begin by considering the classical propagation of strings on space-times with isotropic and anisotropic cosmological singularities. We find that cosmological singularities fall into two classes, in the first class the string evolution is well behaved all the way up to the singularity, whilst in the second class it becomes ill-defined. Then assuming the singularities are regulated by string scale corrections, we consider the implications of the propagation through a `bounce'. It is known that as we evolve through a bounce, quantum strings will become excited giving rise to `particle transmutation'. We reconsider this effect, giving qualitative arguments for the amount of excitation for each class. We find that strings whose physical wavelength at the bounce is less that $\sqrt{{\alpha }^{\prime }}$ inevitably emerge in highly excited states, and that in this regime there is an interesting correspondence between strings on anisotropic cosmological space-times and plane waves. We argue that long wavelength modes, such as those describing cosmological perturbations, will also emerge in mildly excited string scale mass states. Finally we discuss the relevance of this to the propagation of cosmological perturbations in models such as the ekpyrotic/cyclic universe.

15 pages

References in corpus (5)

• Perturbations in bouncing cosmologies: dynamical attractor vs scale invariance
• M Theory Model of a Big Crunch/Big Bang Transition
• Controlling Chaos through Compactification in Cosmological Models with a Collapsing Phase
• Classical Propagation of Strings across a Big Crunch/Big Bang Singularity
• Naturalness in Cosmological Initial Conditions

Cited by in corpus (11)

• A smooth bouncing cosmology with scale invariant spectrum
• Attractors, Statefinders and Observational Measurement for Chameleonic Brans--Dicke Cosmology
• Classical Propagation of Strings across a Big Crunch/Big Bang Singularity
• Stringy corrections to a time-dependent background solution of string and M-Theory
• Two 3-Branes in Randall-Sundrum Setup and Current Acceleration of the Universe
• The string wave function across a Kasner singularity
• Penrose Limits vs String Expansions
• String Pair Production in a Time-Dependent Gravitational Field
• String Excitation by Initial Singularity of Inflation
• Colliding Branes and Formation of Spacetime Singularities
• Winding Strings in Singular Spacetimes