TY - JOUR

T1 - Cosmologies with null singularities and their gauge theory duals

AU - Das, Sumit R.

AU - Michelson, Jeremy

AU - Narayan, K.

AU - Trivedi, Sandip P.

PY - 2007

Y1 - 2007

N2 - We investigate backgrounds of Type IIB string theory with null singularities and their duals proposed in S.R. Das, J. Michelson, K. Narayan, S.P. Trivedi, hep-th/0602107. The dual theory is a deformed N=4 Yang-Mills theory in 3+1 dimensions with couplings dependent on a lightlike direction. We concentrate on backgrounds which become AdS5×S5 at early and late times and where the string coupling is bounded, vanishing at the singularity. Our main conclusion is that in these cases the dual gauge theory is nonsingular. We show this by arguing that there exists a complete set of gauge invariant observables in the dual gauge theory whose correlation functions are nonsingular at all times. The two-point correlator for some operators calculated in the gauge theory does not agree with the result from the bulk supergravity solution. However, the bulk calculation is invalid near the singularity where corrections to the supergravity approximation become important. We also obtain pp-waves which are suitable Penrose limits of this general class of solutions, and construct the matrix membrane theory which describes these pp-wave backgrounds.

AB - We investigate backgrounds of Type IIB string theory with null singularities and their duals proposed in S.R. Das, J. Michelson, K. Narayan, S.P. Trivedi, hep-th/0602107. The dual theory is a deformed N=4 Yang-Mills theory in 3+1 dimensions with couplings dependent on a lightlike direction. We concentrate on backgrounds which become AdS5×S5 at early and late times and where the string coupling is bounded, vanishing at the singularity. Our main conclusion is that in these cases the dual gauge theory is nonsingular. We show this by arguing that there exists a complete set of gauge invariant observables in the dual gauge theory whose correlation functions are nonsingular at all times. The two-point correlator for some operators calculated in the gauge theory does not agree with the result from the bulk supergravity solution. However, the bulk calculation is invalid near the singularity where corrections to the supergravity approximation become important. We also obtain pp-waves which are suitable Penrose limits of this general class of solutions, and construct the matrix membrane theory which describes these pp-wave backgrounds.

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U2 - 10.1103/PhysRevD.75.026002

DO - 10.1103/PhysRevD.75.026002

M3 - Article

AN - SCOPUS:33846427745

SN - 1550-7998

VL - 75

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

IS - 2

M1 - 026002

ER -