Holographic Domains of Anti-de Sitter Space

An AdS_4 brane embedded in AdS_5 exhibits the novel feature that a four-dimensional graviton is localized near the brane, but the majority of the infinite bulk away from the brane where the warp factor diverges does not see four-dimensional gravity. A naive application of the holographic principle from the point of view of the four-dimensional observer would lead to a paradox; a global holographic mapping would require infinite entropy density. In this paper, we show that this paradox is resolved by the proper covariant formulation of the holographic principle. This is the first explicit example of a time-independent metric for which the spacelike formulation of the holographic principle is manifestly inadequate. Further confirmation of the correctness of this approach is that light-rays leaving the brane intersect at the location where we expect four-dimensional gravity to no longer dominate. We also present a simple method of locating CFT excitations dual to a particle in the bulk. We find that the holographic image on the brane moves off to infinity precisely when the particle exits the brane's holographic domain. Our analysis yields an improved understanding of the physics of the AdS_4/AdS_5 model.Comment: 29 pages, 6 figure

Lodged in the throat: Internal infinities and AdS/CFT

In the context of AdS3/CFT2, we address spacetimes with a certain sort of internal infinity as typified by the extreme BTZ black hole. The internal infinity is a null circle lying at the end of the black hole's infinite throat. We argue that such spacetimes may be described by a product CFT of the form CFT-L * CFT-R, where CFT-R is associated with the asymptotically AdS boundary while CFT-L is associated with the null circle. Our particular calculations analyze the CFT dual of the extreme BTZ black hole in a linear toy model of AdS3/CFT2. Since the BTZ black hole is a quotient of AdS3, the dual CFT state is a corresponding quotient of the CFT vacuum state. This state turns out to live in the aforementioned product CFT. We discuss this result in the context of general issues of AdS/CFT duality and entanglement entropy.Comment: 11 pages, 2 figures; v2 - some typos corrected, minor revision

News from the Virasoro algebra

It is shown that the local quantum field theory of the chiral energy-momentum tensor with central charge c = 1 coincides with the gauge invariant subtheory of the chiral SU(2) current algebra at level 1, where the gauge group is the global SU(2) symmetry. At higher level, the same scheme gives rise to W-algebra extensions of the Virasoro algebra. (orig.)Available from TIB Hannover: RA 2999(93-115) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Subfactors and coset models

Some facts about von Neumann algebras and finite index inclusions of factors are viewed in the context of local quantum field theory. The possibility of local fields intertwining superselection sectors with braid group statistics is explored. Conformal embeddings and coset models serve as examples. The associated symmetry concept is pointed out. (orig.)Available from TIB Hannover: RA 2999(93-116) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Weak C"* Hopf symmetry

Weak C"* Hopf algebras act as global symmetries in low-dimensional quantum field theories, when braid group statistics prevents ordinary symmetries. Charged fields transform linearly in finite multiplets, and the observables are precisely the gauge invariants. Possibilities to construct field algebras with weak C"* Hopf symmetry from a given theory of local observables are discussed. (orig.)15 refs.Available from TIB Hannover: RA 2999(96-231) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Comments on a recent solution to Wightman's axioms

A class of exact Wightman functionals satisfying all fundamental physical requirements in an arbitrary number of space-time dimensions, which bear the appearance of describing interacting fields, was recently constructed by C. Read (1994). It is shown here, that the construction can be considerably generalized, and that even the enlarged class belongs to the Borchers class of a system of generalized free fields. (orig.)Available from TIB Hannover: RA 2999(95-149) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman