1,394 research outputs found
N=1 SUSY Conformal Block Recursive Relations
We present explicit recursive relations for the four-point superconformal
block functions that are essentially particular contributions of the given
conformal class to the four-point correlation function. The approach is based
on the analytic properties of the superconformal blocks as functions of the
conformal dimensions and the central charge of the superconformal algebra. The
results are compared with the explicit analytic expressions obtained for
special parameter values corresponding to the truncated operator product
expansion. These recursive relations are an efficient tool for numerically
studying the four-point correlation function in Super Conformal Field Theory in
the framework of the bootstrap approach, similar to that in the case of the
purely conformal symmetry.Comment: 12 pages, typos corrected, reference adde
Information geometric approach to the renormalisation group
We propose a general formulation of the renormalisation group as a family of
quantum channels which connect the microscopic physical world to the observable
world at some scale. By endowing the set of quantum states with an
operationally motivated information geometry, we induce the space of
Hamiltonians with a corresponding metric geometry. The resulting structure
allows one to quantify information loss along RG flows in terms of the
distinguishability of thermal states. In particular, we introduce a family of
functions, expressible in terms of two-point correlation functions, which are
non increasing along the flow. Among those, we study the speed of the flow, and
its generalization to infinite lattices.Comment: Accepted in Phys. Rev.
Boundary S-matrix for the Gross-Neveu Model
We study the scattering theory for the Gross-Neveu model on the half-line. We
find the reflection matrices for the elementary fermions, and by fusion we
compute the ones for the two-particle bound-states, showing that they satisfy
non-trivial bootstrap consistency conditions. We also compute more general
reflection matrices for the Gross-Neveu model and the nonlinear sigma model,
and argue that they correspond to the integrable boundary conditions we
identified in our previous paper hep-th/9809178.Comment: 13 pages, latex file, final version to appear in PL
Conserved charges in the chiral 3-state Potts model
We consider the perturbations of the 3-state Potts conformal field theory
introduced by Cardy as a description of the chiral 3-state Potts model. By
generalising Zamolodchikov's counting argument and by explicit calculation we
find new inhomogeneous conserved currents for this theory. We conjecture the
existence of an infinite set of conserved currents of this form and discuss
their relevance to the description of the chiral Potts models
g-function in perturbation theory
We present some explicit computations checking a particular form of gradient
formula for a boundary beta function in two-dimensional quantum field theory on
a disc. The form of the potential function and metric that we consider were
introduced in hep-th/9210065, hep-th/9311177 in the context of background
independent open string field theory. We check the gradient formula to the
third order in perturbation theory around a fixed point. Special consideration
is given to situations when resonant terms are present exhibiting logarithmic
divergences and universal nonlinearities in beta functions. The gradient
formula is found to work to the given order.Comment: 1+14 pages, Latex; v.2: typos corrected; v.3: minor corrections, to
appear in IJM
On the Finite Temperature Formalism in Integrable Quantum Field Theories
Two different theoretical formulations of the finite temperature effects have
been recently proposed for integrable field theories. In order to decide which
of them is the correct one, we perform for a particular model an explicit check
of their predictions for the one-point function of the trace of the
stress-energy tensor, a quantity which can be independently determined by the
Thermodynamical Bethe Ansatz.Comment: 12 pages, corrected some typos and an equatio
The long delayed solution of the Bukhvostov Lipatov model
In this paper I complete the solution of the Bukhvostov Lipatov model by
computing the physical excitations and their factorized S matrix. I also
explain the paradoxes which led in recent years to the suspicion that the model
may not be integrable.Comment: 9 page
27/32
We show that when an N=2 SCFT flows to an N=1 SCFT via giving a mass to the
adjoint chiral superfield in a vector multiplet with marginal coupling, the
central charges a and c of the N=2 theory are related to those of the N=1
theory by a universal linear transformation. In the large N limit, this
relationship implies that the central charges obey a_IR/a_UV=c_IR/c_UV=27/32.
This gives a physical explanation to many examples of this number found in the
literature, and also suggests the existence of a flow between some theories not
previously thought to be connected.Comment: 3 pages. v2: references added, minor typos correcte
Correlation functions of disorder fields and parafermionic currents in Z(N) Ising models
We study correlation functions of parafermionic currents and disorder fields
in the Z(N) symmetric conformal field theory perturbed by the first thermal
operator. Following the ideas of Al. Zamolodchikov, we develop for the
correlation functions the conformal perturbation theory at small scales and the
form factors spectral decomposition at large ones. For all N there is an
agreement between the data at the intermediate distances. We consider the
problems arising in the description of the space of scaling fields in perturbed
models, such as null vector relations, equations of motion and a consistent
treatment of fields related by a resonance condition.Comment: 41 pp. v2: some typos and references are corrected
Born-Infeld Type Extension of (Non-)Critical Gravity
We consider the Born-Infeld type extension of (non-)critical gravity which is
higher curvature gravity on Anti de-Sitter space with specific combinations of
scalar curvature and Ricci tensor. This theory may also be viewed as a natural
extension of three-dimensional Born-Infeld new massive gravity to arbitrary
dimensions. We show that this extension is consistent with holographic
-theorem and scalar graviton modes are absent in this theory. After showing
that ghost modes in the theory can be truncated consistently by appropriate
boundary conditions, we argue that the theory is classically equivalent to
Einstein gravity at the non-linear level. Black hole solutions are discussed in
the view point of the full non-linear classical equivalence between the theory
and Einstein gravity. Holographic entanglement entropy in the theory is also
briefly commented on.Comment: 1+13 pages, improvements in presentation, references added, accepted
to PR
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