Graceful exit problem and stress-energy-momentum tensors revisited in the two-dimensional string cosmology

Abstract

We study the graceful exit problem and the role of the stress-energy-momentum tensors in the two-dimensional string cosmology. The one-loop quantum correction of conformal fields is incorporated in the arbitrary large $N$ limit to ensure exact quantum solvability. The only solution which gives the bounded curvature with the asymptotic flatness is restricted to the first branch under some conditions. However, even in this case, the accelerating expansion is forever. We show that the only nonvanishing quantum stress-momentum tensor is the pressure part($T_{xx}$) which is of relevance to the dynamical evolution of the universe in the comoving coordinate. The quantum energy part is zero since the negative contribution of the induced conformal matters always cancels the positive quantity of the induced dilaton part in terms of the constraint equation.

14 pages, revtex, 1 figure, some erraneous equations and misunderstood expressions are corrected

References in corpus (5)

• Duality and Dilaton
• One-Loop Superstring Cosmology and the Non-Singular Universe
• Graceful exit in quantum string cosmology
• Back Reaction and Graceful Exit in String Inflationary Cosmology
• Singularity and exit problems in two-dimensional string cosmology

Cited by in corpus (9)

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• Accelerated expansion in bosonic and fermionic 2D cosmologies with quantum effects
• Initial singularity free quantum cosmology in two-dimensional Brans-Dicke theory
• AdS_2 and quantum stability in the CGHS model
• Accelerating universe in two-dimensional noncommutative dilaton cosmology
• Transition from AdS universe to DS universe in the BPP model
• Exactly solvable models of two-dimensional dilaton cosmology with quantum backreaction
• Future singularity free accelerating expansion with the modified Poisson brackets
• Two non-commutative parameters and regular cosmological phase transition in the semi-classical dilaton cosmology