In this paper we compute the low energy absorption cross section for minimally coupled massles scalars and spin-1͞2 particles into a general spherically symmetric black hole in arbitrary dimensions. The scalars have a cross section equal to the area of the black hole, while the spin-1͞2 particles give the area measured in a flat spatial metric conformally related to the true metric. [S0031-9007(96)02146-1] PACS numbers: 04.70. Dy, 04.65.+e, Recently there has been great interest in the possibility of relating some of the properties of classical black hole solutions of the low energy supergravity [1] limits of string theories to a more fundamental microscopic description based on strings and D-branes. In particular extremal black holes correspond in many cases to BPS (Bogomolny-Prasad-Sommerfeld) states of the theory, and their number for a given set of charges is expected to be independent of coupling. This allows a comparison between the number of particle states (computable at weak coupling) with the Bekenstein-Hawking entropy of the black hole (which would exist for the same charges at strong coupling). Agreement is found in all the cases investigated so far [2], thus suggesting that the Bekenstein-Hawking entropy for a hole does indeed correspond to the count of microstates for the hole, though it is still unclear where these microstates actually reside.To study interesting processes like Hawking radiation, we need to allow quanta to fall into the hole, rendering it non-BPS, after which it would evaporate back towards extremality. Are there relations between the properties of particle states at weak coupling and properties of black holes, when we consider deviations from extremality? One result in this direction was presented in [3] where it was shown that if one naively ignores interaction between non-BPS states, then the degeneracy of a collection of branes and antibranes continues to reproduce the Bekenstein-Hawking entropy for nonextremal holes and leads to the correct Hawking temperature. In [4,5] it was found that if one computes the low energy cross section for absorption and emission of neutral scalars in the 4 1 1 dimensional extremal black hole, then this cross section agrees exactly with that for absorption or emission with the corresponding collection of branes at weak coupling. This result has been extended to charged scalars in four and five dimensions in [6]. Recently it has been shown [7] that the D-brane decay reproduces the correct grey body factors both for neutral and charged scalar emission.To discover if these are examples of a general pattern of universality in the theory, we need to observe universalities that may exist in the interactions of classical black holes. The absorption cross section for low energy particles in 3 1 1 dimensional black holes was studied extensively in the past, for example, by Starobinski and Churilov [8], Gibbons [9], Page [10], and Unruh [11]. In these calculations if we consider the particle to be a massless minimally coupled scalar, then we find that the ...
We compute the leading order (in coupling) rate of emission of low energy quanta from a slightly nonextremal system of 1 and 5 D-branes. We also compute the classical cross-section, and hence the Hawking emission rate, for low energy scalar quanta for the black hole geometry that corresponds to these branes (at sufficiently strong coupling). These rates are found to agree with each other.Comment: harvmac, 17 pages; minor typos and a reference correcte
We describe a field theoretic formulation for one-dimensional string theory. It is given by the collective field representation of the matrix model and leads to a physical interpretation of the theory as that of a massless scalar field in two dimensions. The additional dimension, coming from the large-N color of the matrix model, has an extent which goes to infinity in the continuum limit. The interactions of the field theory are non-zero only at the boundaries of this additional dimension.
We propose that the euclidean bilocal collective field theory of critical large-N vector models provides a complete definition of the proposed dual theory of higher spin fields in anti de-Sitter spaces. We show how this bilocal field can be decomposed into an infinite number of even spin fields in one more dimension. The collective field has a nontrivial classical solution which leads to a O(N ) thermodynamic entropy characteristic of the lower dimensional theory, as required by general considerations of holography. A subtle cancellation of the entropy coming from the bulk fields in one higher dimension with O(1) contributions from the classical solution ensures that the subleading terms in thermodynamic quantities are of the expected form. While the spin components of the collective field transform properly under dilatational, translational and rotational isometries of AdS, special conformal transformations mix fields of different spins indicating a need for a nonlocal map between the two sets of fields. We discuss the nature of the propagating degrees of freedom through a hamiltonian form of collective field theory and argue that nonsinglet states which are present in an euclidean version are related to nontrivial backgrounds.
The non-perturbative formulation of 2-dimensional quantum gravity in terms of the large-N limit of matrix models is studied to include the effects of higher order curvature terms. This leads to matrix models whose potential contains a symmetry breaking term of the form Tr ϕAϕA, where A is a given fixed matrix. This is studied in d = 0 dimensions and effectively induces additional terms of the form ( Tr ϕk)2 in the one matrix potential. An exact solution to leading order of the potential V(ϕ) = 1/2 Tr ϕ2 + g/N Tr ϕ4 + g′/N2 ( Tr ϕ2)2 is presented leading to 3 phases: γ = −1/2 (smooth surfaces), γ = 1/2 (branched polymer) and γ = 1/3 (intermediate phase). Including a Tr ϕ6 term in the potential gives rise to an additional phase with γ = 1/4. It is conjectured that for the general polynomial potential there are phases with γ = 1/n, n = 2, 3, …. The γ > 0 phases may correspond to c > 1 matter coupled to 2-dimensional gravity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.