210 research outputs found
Thermodynamics of the quantum Landau-Lifshitz model
We present thermodynamics of the quantum su(1,1) Landau-Lifshitz model,
following our earlier exposition [J. Math. Phys. 50, 103518 (2009)] of the
quantum integrability of the theory, which is based on construction of
self-adjoint extensions, leading to a regularized quantum Hamiltonian for an
arbitrary n-particle sector. Starting from general discontinuity properties of
the functions used to construct the self-adjoint extensions, we derive the
thermodynamic Bethe Ansatz equations. We show that due to non-symmetric and
singular kernel, the self-consistency implies that only negative chemical
potential values are allowed, which leads to the conclusion that, unlike its
su(2) counterpart, the su(1,1) LL theory at T=0 has no instabilities.Comment: 10 page
Expansion in Feynman Graphs as Simplicial String Theory
We show that the series expansion of quantum field theory in the Feynman
diagrams can be explicitly mapped on the partition function of the simplicial
string theory -- the theory describing embeddings of the two--dimensional
simplicial complexes into the space--time of the field theory. The summation
over two--dimensional geometries in this theory is obtained from the summation
over the Feynman diagrams and the integration over the Schwinger parameters of
the propagators. We discuss the meaning of the obtained relation and derive the
one--dimensional analog of the simplicial theory on the example of the free
relativistic particle.Comment: Latex, 11pp, Minor mintakes are correcte
Conformal boundary and geodesics for and the plane wave: Their approach in the Penrose limit
Projecting on a suitable subset of coordinates, a picture is constructed in
which the conformal boundary of and that of the plane wave
resulting in the Penrose limit are located at the same line. In a second line
of arguments all and plane wave geodesics are constructed in
their integrated form. Performing the Penrose limit, the approach of null
geodesics reaching the conformal boundary of to that of the
plane wave is studied in detail. At each point these null geodesics of
form a cone which degenerates in the limit.Comment: some statements refined, chapter 5 rewritten to make it more precise,
some typos correcte
Holographic three-point functions of giant gravitons
Working within the AdS/CFT correspondence we calculate the three-point
function of two giant gravitons and one pointlike graviton using methods of
semiclassical string theory and considering both the case where the giant
gravitons wrap an S^3 in S^5 and the case where the giant gravitons wrap an S^3
in AdS_5. We likewise calculate the correlation function in N=4 SYM using two
Schur polynomials and a single trace chiral primary. We find that the gauge and
string theory results have structural similarities but do not match perfectly,
and interpret this in terms of the Schur polynomials' inability to interpolate
between dual giant and pointlike gravitons.Comment: 21 page
BMN operators and string field theory
We extract from gauge theoretical calculations the matrix elements of the SYM
dilatation operator. By the BMN correspondence this should coincide with the
3-string vertex of light cone string field theory in the pp-wave background. We
find a mild but important discrepancy with the SFT results. If the modified
matrix elements are used, the anomalous dimensions are
exactly reproduced without the need for a contact interaction in the single
string sector.Comment: 11 pages; v2: references adde
Quasilocality of joining/splitting strings from coherent states
Using the coherent state formalism we calculate matrix elements of the
one-loop non-planar dilatation operator of SYM between operators
dual to folded Frolov-Tseytlin strings and observe a curious scaling behavior.
We comment on the {\it qualitative} similarity of our matrix elements to the
interaction vertex of a string field theory. In addition, we present a solvable
toy model for string splitting and joining. The scaling behaviour of the matrix
elements suggests that the contribution to the genus one energy shift coming
from semi-classical string splitting and joining is small.Comment: 17 pages, 7 figures in 11 file
Beyond the Planar Limit in ABJM
In this article we consider gauge theories with a U(N)X U(N) gauge group. We
provide, for the first time, a complete set of operators built from scalar
fields that are in the bi fundamental of the two groups. Our operators
diagonalize the two point function of the free field theory at all orders in
1/N. We then use this basis to investigate non-planar anomalous dimensions in
the ABJM theory. We show that the dilatation operator reduces to a set of
decoupled harmonic oscillators, signaling integrability in a nonplanar large N
limit.Comment: v2: minor revisison
Predictions for PP-wave string amplitudes from perturbative SYM
The role of general two-impurity multi-trace operators in the BMN
correspondence is explored. Surprisingly, the anomalous dimensions of all
two-impurity multi-trace BMN operators to order g_2^2\lambda' are completely
determined in terms of single-trace anomalous dimensions. This is due to
suppression of connected field theory diagrams in the BMN limit and this fact
has important implications for some string theory processes on the PP-wave
background. We also make gauge theory predictions for the matrix elements of
the light-cone string field theory Hamiltonian in the two string-two string and
one string-three string sectors.Comment: 46 pages, 12 figures. V3:typos correcte
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