1,964 research outputs found
Scattering of low lying states in the black hole atmosphere
We investigate finite effects in string theory on a black hole
background. By explicitly computing tree level scattering amplitudes, we
confirm a duality between seemingly different states recently conjectured by
Giveon, Itzhaki, and Kutasov in [arXiv:1603.05822]. We verify that the relevant
3-point functions factorize in such a way that the duality between oscillator
and winding states becomes manifest. This leads to determine the precise
normalization of the dual vertex operators, and confirms at the level of the
interacting theory the identification of states suggested by the analysis of
the spectrum. This result implies a duality between two seemingly distinct
mechanisms driving the violation of the string winding number in the black hole
atmosphere.Comment: 12 pages, 1 figur
The large D limit of dimensionally continued gravity
In a recent paper [arXiv:1302.6382] Emparan, Suzuki, and Tanabe studied
general relativity in the limit in which the number of spacetime dimensions D
tends to infinity. They showed that, in such limit, the theory simplifies
notably. It reduces to a theory whose fundamental objects, black holes and
black branes, behave as non-interacting particles. Here, we consider a
different way of extending gravity to D dimensions. We present a special limit
of dimensionally continued gravity in which black holes retain their
gravitational interaction at large D and still have entropy proportional to the
mass. The similarities and differences with the limit considered in
[arXiv:1302.6382] are discussed.Comment: 10 page
On Spectral Flow Symmetry and Knizhnik-Zamolodchikov Equation
It is well known that five-point function in Liouville field theory provides
a representation of solutions of the SL(2,R)_k Knizhnik-Zamolodchikov equation
at the level of four-point function. Here, we make use of such representation
to study some aspects of the spectral flow symmetry of sl(2)_k affine algebra
and its action on the observables of the WZNW theory. To illustrate the
usefulness of this method we rederive the three-point function that violates
the winding number in SL(2,R) in a very succinct way. In addition, we prove
several identities holding between exact solutions of the
Knizhnik-Zamolodchikov equation.Comment: 10 pages, no figures. v2: Typos corrected, formula and references
added. v3: typo corrected in equation (20
TT-deformations, AdS/CFT and correlation functions
A solvable irrelevant deformation of AdS3/CFT2 correspondence leading to a theory with Hagedorn spectrum at high energy has been recently proposed. It consists of a single trace deformation of the boundary theory, which is inspired by the recent work on solvable TT¯ deformations of two-dimensional CFTs. Thought of as a worldsheet σ-model, the interpretation of the deformed theory from the bulk viewpoint is that of string theory on a background that interpolates between AdS3 in the IR and a linear dilaton vacuum of little string theory in the UV. The insertion of the operator that realizes the deformation in the correlation functions produces a logarithmic divergence, leading to the renormalization of the primary operators, which thus acquire an anomalous dimension. We compute this anomalous dimension explicitly, and this provides us with a direct way of determining the spectrum of the theory. We discuss this and other features of the correlation functions in presence of the deformation.Fil: Giribet, Gaston Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentin
Aspects of the free field description of string theory on AdS_3
The near boundary limit of string theory in AdS_3 is analysed using the
Wakimoto free field representation of SL(2,R). The theory is considered as a
direct product of the SL(2,R)/U(1) coset and a free boson. Correlation
functions are constructed generalizing to the non-compact case the integral
representation of conformal blocks introduced by Dotsenko in the compact SU(2)
CFT. Sectors of the theory obtained by spectral flow manifestly appear. The
formalism naturally leads to consider scattering processes violating winding
number conservation. The consistency of the procedure is verified in the
factorization limit.Comment: 25 pages, typos corrected, references added, to appear in JHE
The Brown-York mass of black holes in Warped Anti-de Sitter space
We give a direct computation of the mass of black holes in Warped Anti-de
Sitter space (WAdS) in terms of the Brown-York stress-tensor at the boundary.
This permits to explore to what extent the holographic renormalization
techniques can be applied to such type of deformation of AdS. We show that,
despite some components of the boundary stress-tensor diverge and resist to be
regularized by the introduction of local counterterms, the precise combination
that gives the quasilocal energy density yields a finite integral. The result
turns out to be in agreement with previous computations of the black hole mass
obtained with different approaches. This is seen to happen both in the case of
Topologically Massive Gravity and of the so-called New Massive Gravity. Here,
we focus our attention on the latter. We observe that, despite other conserved
charges diverge in the near boundary limit, the finite part in the large radius
expansion captures the physically relevant contribution. We compute the black
hole angular momentum in this way and we obtain a result that is in perfect
agreement with previous calculations.Comment: 8 pages. v2 discussion and appendix added, references added. To
appear in JHE
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