7 research outputs found
Random matrix analysis of the QCD sign problem for general topology
Motivated by the important role played by the phase of the fermion
determinant in the investigation of the sign problem in lattice QCD at nonzero
baryon density, we derive an analytical formula for the average phase factor of
the fermion determinant for general topology in the microscopic limit of chiral
random matrix theory at nonzero chemical potential, for both the quenched and
the unquenched case. The formula is a nontrivial extension of the expression
for zero topology derived earlier by Splittorff and Verbaarschot. Our
analytical predictions are verified by detailed numerical random matrix
simulations of the quenched theory.Comment: 33 pages, 9 figures; v2: minor corrections, references added, figures
with increased statistics, as published in JHE
Mixed correlation functions in the 2-matrix model, and the Bethe ansatz
Using loop equation technics, we compute all mixed traces correlation
functions of the 2-matrix model to large N leading order. The solution turns
out to be a sort of Bethe Ansatz, i.e. all correlation functions can be
decomposed on products of 2-point functions. We also find that, when the
correlation functions are written collectively as a matrix, the loop equations
are equivalent to commutation relations.Comment: 38 pages, LaTex, 24 figures. misprints corrected, references added, a
technical part moved to appendi
1/2-BPS Correlators as c=1 S-matrix
We argue from two complementary viewpoints of Holography that the 2-point
correlation functions of 1/2-BPS multi-trace operators in the large-N (planar)
limit are nothing but the (Wick-rotated) S-matrix elements of c=1 matrix model.
On the bulk side, we consider an Euclideanized version of the so-called
bubbling geometries and show that the corresponding droplets reach the
conformal boundary. Then the scattering matrix of fluctuations of the droplets
gives directly the two-point correlators through the GKPW prescription. On the
Yang-Mills side, we show that the two-point correlators of holomorphic and
anti-holomorphic operators are essentially equivalent with the transformation
functions between asymptotic in- and out-states of c=1 matrix model. Extension
to non-planar case is also discussed.Comment: 28 pages, 3 figures, corrected typos, version to appear in JHE
Abelian and nonabelian vector field effective actions from string field theory
The leading terms in the tree-level effective action for the massless fields
of the bosonic open string are calculated by integrating out all massive fields
in Witten's cubic string field theory. In both the abelian and nonabelian
theories, field redefinitions make it possible to express the effective action
in terms of the conventional field strength. The resulting actions reproduce
the leading terms in the abelian and nonabelian Born-Infeld theories, and
include (covariant) derivative corrections.Comment: 49 pages, 1 eps figur