David A. Lowe

Holographic representation of local bulk operators

The Lorentzian anti-de Sitter/conformal field theory correspondence implies a map between local operators in supergravity and nonlocal operators in the CFT. By explicit computation we construct CFT operators which are dual to local bulk fields in the semiclassical limit. The computation is done for general dimension in global, Poincare and Rindler coordinates. We find that the CFT operators can be taken to have compact support in a region of the complexified boundary whose size is set by the bulk radial position. We show that at finite N the number of independent commuting operators localized within a bulk volume saturates the holographic bound.

Microscopic entropy of N=2 extremal black holes

String theory is used to compute the microscopic entropy for several examples of black holes in compactifications with

Black hole complementarity versus locality

N=2

N = 2 SUPERSYMMETRIC GAUGE THEORIES, BRANES AND ORIENTIFOLDS

supersymmetry. Agreement with the Bekenstein-Hawking entropy and the moduli-independent

Constructing local bulk observables in interacting AdS/CFT

N=2

STATISTICAL ENTROPY OF NONEXTREMAL FOUR-DIMENSIONAL BLACK HOLES AND U DUALITY

area formula is found in all cases.

Holography, cosmology and the second law of thermodynamics

The evaporation of a large mass black hole can be described throughout most of its lifetime by a low-energy effective theory defined on a suitably chosen set of smooth spacelike hypersurfaces. The conventional argument for information loss rests on the assumption that the effective theory is a local quantum field theory. We present evidence that this assumption fails in the context of string theory. The commutator of operators in light-front string theory, corresponding to certain low-energy observers on opposite sides of the event horizon, remains large even when these observers are spacelike separated by a macroscopic distance. This suggests that degrees of freedom inside a black hole should not be viewed as independent from those outside the event horizon. These nonlocal effects are only significant under extreme kinematic circumstances, such as in the high-redshift geometry of a black hole. Commutators of spacelike separated operators corresponding to ordinary low-energy observers in Minkowski space are strongly suppressed in string theory. \textcopyright{} 1995 The American Physical Society.

Probing F-theory with multiple branes

Abstract Starting with configurations of fourbranes, fivebranes, sixbranes and orientifolds in type 11A string theory we derive via M-theory the curves solving N = 2 supersymmetric gauge theories with gauge groups SO ( N ) and Sp (2 N ). We also obtain new curves describing theories with product gauge groups. A crucial role in the discussion is played by the interaction of the orientifolds with the NS-fivebranes.

Heterotic matrix string theory

Local operators in the bulk of anti-de Sitter can be represented as smeared operators in the dual conformal field theory. We show how to construct these bulk observables by requiring that the bulk operators commute at spacelike separation. This extends our previous work by taking interactions into account. Large-N factorization plays a key role in the construction. We show diagrammatically how this procedure is related to bulk Feynman diagrams.

Initial state effects on the cosmic microwave background and trans-Planckian physics

We identify the states in string theory which are responsible for the entropy of near-extremal rotating four-dimensional black holes in {ital N}=8 supergravity. For black holes far from extremality (with no rotation), the Bekenstein-Hawking entropy is exactly matched by a mysterious duality invariant extension of the formulas derived for near-extremal black holes states. {copyright} {ital 1996 The American Physical Society.}