3,298 research outputs found
Regular and Irregular Boundary Conditions in the AdS/CFT Correspondence
We expand on Klebanov and Witten's recent proposal for formulating the
AdS/CFT correspondence using irregular boundary conditions. The proposal is
shown to be correct to any order in perturbation theory.Comment: 7 pages, typos correcte
First passages in bounded domains: When is the mean first passage time meaningful?
We study the first passage statistics to adsorbing boundaries of a Brownian
motion in bounded two-dimensional domains of different shapes and
configurations of the adsorbing and reflecting boundaries. From extensive
numerical analysis we obtain the probability P(\omega) distribution of the
random variable \omega=\tau_1/(\tau_1+\tau_2), which is a measure for how
similar the first passage times \tau_1 and \tau_2 are of two independent
realisations of a Brownian walk starting at the same location. We construct a
chart for each domain, determining whether P(\omega) represents a unimodal,
bell-shaped form, or a bimodal, M-shaped behaviour. While in the former case
the mean first passage time (MFPT) is a valid characteristic of the first
passage behaviour, in the latter case it is an insufficient measure for the
process. Strikingly we find a distinct turnover between the two modes of
P(\omega), characteristic for the domain shape and the respective location of
absorbing and reflective boundaries. Our results demonstrate that large
fluctuations of the first passage times may occur frequently in two-dimensional
domains, rendering quite vague the general use of the MFPT as a robust measure
of the actual behaviour even in bounded domains, in which all moments of the
first passage distribution exist.Comment: 9 pages, 6 figure
Correlation functions in the Coulomb branch of N=4 SYM from AdS/CFT correspondence
In the present paper we study SU(N)->S(U(N/2)xU(N/2)) symmetry breaking in
N=4 SYM via AdS/CFT correspondence. We consider two stacks of N/2 parallel D3
branes separated by a distance 2\vec d. In this case there is mixing between
the different l-wave dilatonic KK modes. We calculate certain the two point
correlation functions in the dual gauge theory. Due to mode mixing, the
diagonal correlation functions have 1/N conformal-like correction as well as
deformation terms. The off-diagonal correlators are also non-vanishing and
their leading order is 1/N. We discuss briefly the spectrum of the glueball
exitations.Comment: 25 pages, more comments on two throat geometry, decoupling limit and
correction terms, a few typos corrected, two references added; to appear in
Phys.Rev.
Conformal Field Theory Correlators from Classical Field Theory on Anti-de Sitter Space II. Vector and Spinor Fields
We use the AdS/CFT correspondence to calculate CFT correlation functions of
vector and spinor fields. The connection between the AdS and boundary fields is
properly treated via a Dirichlet boundary value problem.Comment: 14 pages, LaTeX2e with amsmath,amsfonts packages; v2:interactions
section corrected, reference adde
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