138 research outputs found
Duality from Topological Symmetry
We describe topological gauge theories for which duality properties are
encoded by construction. We study them for compact manifolds of dimensions
four, eight and two. The fields and their duals are treated symmetrically,
within the context of field--antifield unification. Dual formulations
correspond to different gauge-fixings of the topological symmetry. We also
describe novel features in eight-dimensional theories, and speculate about
their possible "Abelian" descriptions.Comment: 30 pages, harvmac file, references adde
Integrating Over Higgs Branches
We develop some useful techinques for integrating over Higgs branches in
supersymmetric theories with 4 and 8 supercharges. In particular, we define a
regularized volume for hyperkahler quotients. We evaluate this volume for
certain ALE and ALF spaces in terms of the hyperkahler periods. We also reduce
these volumes for a large class of hyperkahler quotients to simpler integrals.
These quotients include complex coadjoint orbits, instanton moduli spaces on
R^4 and ALE manifolds, Hitchin spaces, and moduli spaces of parabolic Higgs
bundles on Riemann surfaces. In the case of Hitchin spaces the evaluation of
the volume reduces to a summation over solutions of Bethe Ansatz equations for
the non-linear Schroedinger system. We discuss some applications of our
results.Comment: 32pp. harvmac big mode; v.2 34pp. typos fixed, sections 4.1, 5.2
substantially improve
D-particle bound states and generalized instantons
We compute the principal contribution to the index in the supersymmetric
quantum mechanical systems which are obtained by reduction to 0+1 dimensions of
, super-Yang-Mills theories with gauge group SU(N).
The results are: for ,
for D=10. We also discuss the D=3 case.Comment: harvmac, 24 pages; v2. references added, typos corrected; v3. one
more reference adde
Asymmetry-Driven Structure Formation in Pair Plasmas
The nonlinear propagation of electromagnetic waves in pair plasmas, in which
the electrostatic potential plays a very important but subdominant role of a
"binding glue" is investigated. Several mechanisms for structure formation are
investigated, in particular, the "asymmetry" in the initial temperatures of the
constituent species. It is shown that the temperature asymmetry leads to a
(localizing) nonlinearity that is new and qualitatively different from the ones
originating in ambient mass or density difference. The temperature asymmetry
driven focusing-defocusing nonlinearity supports stable localized wave
structures in 1-3 dimensions, which, for certain parameters, may have flat-top
shapes.Comment: 23 pages, 6 figures, introduction revised, edited typos, accepted for
publication in Phys. Rev.
On the Boundary Entropy of One-dimensional Quantum Systems at Low Temperature
The boundary beta-function generates the renormalization group acting on the
universality classes of one-dimensional quantum systems with boundary which are
critical in the bulk but not critical at the boundary. We prove a gradient
formula for the boundary beta-function, expressing it as the gradient of the
boundary entropy s at fixed non-zero temperature. The gradient formula implies
that s decreases under renormalization except at critical points (where it
stays constant). At a critical point, the number exp(s) is the ``ground-state
degeneracy,'' g, of Affleck and Ludwig, so we have proved their long-standing
conjecture that g decreases under renormalization, from critical point to
critical point. The gradient formula also implies that s decreases with
temperature except at critical points, where it is independent of temperature.
The boundary thermodynamic energy u then also decreases with temperature. It
remains open whether the boundary entropy of a 1-d quantum system is always
bounded below. If s is bounded below, then u is also bounded below.Comment: 12 pages, Latex, 1 eps-figure; v2: some expository material added, a
slightly more condensed version of the paper is publihed in Phys. Rev. Let
Open-closed string correspondence: D-brane decay in curved space
This paper analyzes the effect of curved closed string backgrounds on the
stability of D-branes within boundary string field theory. We identify the
non-local open string background that implements shifts in the closed string
background and analyze the tachyonic sector off-shell. The renormalization
group flow reveals some characteristic properties, which are expected for a
curved background, like the absence of a stable space-filling brane. In
3-dimensions we describe tachyon condensation processes to lower-dimensional
branes, including a curved 2-dimensional brane. We argue that this 2-brane is
perturbatively stable. This is in agreement with the known maximally symmetric
WZW-branes and provides further support to the bulk-boundary factorization
approach to open-closed string correspondence.Comment: 23 pages, harvma
Generalized Conifolds and 4d N=1 SCFT
This paper lays groundwork for the detailed study of the non-trivial
renormalization group flow connecting supersymmetric fixed points in four
dimensions using string theory on AdS spaces. Specifically, we consider
D3-branes placed at singularities of Calabi-Yau threefolds which generalize the
conifold singularity and have an ADE classification. The
superconformal theories dictating their low-energy dynamics are infrared fixed
points arising from deforming the corresponding ADE
superconformal field theories by mass terms for adjoint chiral fields. We probe
the geometry with a single -brane and discuss the near-horizon supergravity
solution for a large number of coincident -branes.Comment: harvmac 27pp; v2. refs added, typos corrected, abstract renormalized,
v3. more of that sort, version to appear in JHE
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