863 research outputs found
The origin of scale-scale correlations of the density perturbations during inflation
We show that scale-scale correlations are a generic feature of slow-roll
inflation theories. These correlations result from the long-time tails
characteristic of the time dependent correlations because the long wavelength
density perturbation modes are diffusion-like. A relationship between the
scale-scale correlations and time-correlations is established providing a way
to reveal the time correlations of the perturbations during inflation. This
mechanism provides for a testable prediction that the scale-scale correlations
at two different spatial points will vanish.Comment: Accepted for publication, International Journal of Modern Physics,
vol. 8 No.6 (Dec 1999
Nonabelian Fields in Exact String Solutions
Within the framework of "anomalously gauged" Wess-Zumino-Witten (WZW) models,
we construct solutions which include nonabelian fields. Both compact and
noncompact groups are discussed. In the case of compact groups, as an example
of background containing nonabelian fields, we discuss conformal theory on the
coset, which is the natural generalization of the 2D monopole
theory corresponding to the coset. In noncompact case, we
consider examples with and cosets.Comment: 15 pages, Late
On Black Hole Thermodynamics of 2-D Type 0A
We present a detailed analysis of the thermodynamics of two dimensional black
hole solutions to type 0A with q units of electric and magnetic flux. We
compute the free energy and derived quantities such as entropy and mass for an
arbitrary non-extremal black hole. The free energy is non-vanishing, in
contrast to the case of dilatonic 2-d black holes without electric and magnetic
fluxes. The entropy of the extremal black holes is obtained, and we find it to
be proportional to q^2, the square of the RR flux. We compare these
thermodynamics quantities with those from candidate matrix model duals.Comment: 20pp, v2: references adde
One-loop Effective Action of the Holographic Antisymmetric Wilson Loop
We systematically study the spectrum of excitations and the one-loop
determinant of holographic Wilson loop operators in antisymmetric
representations of supersymmetric Yang-Mills theory.
Holographically, these operators are described by D5-branes carrying electric
flux and wrapping an in the bulk
background. We derive the dynamics of both bosonic and fermionic excitations
for such D5-branes. A particularly important configuration in this class is the
D5-brane with worldvolume and units of electric flux,
which is dual to the circular Wilson loop in the totally antisymmetric
representation of rank . For this Wilson loop, we obtain the spectrum, show
explicitly that it is supersymmetric and calculate the one-loop effective
action using heat kernel techniques.Comment: 42 pages, one tabl
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