863 research outputs found
Cauchy conformal fields in dimensions d>2
Holomorphic fields play an important role in 2d conformal field theory. We
generalize them to d>2 by introducing the notion of Cauchy conformal fields,
which satisfy a first order differential equation such that they are determined
everywhere once we know their value on a codimension 1 surface. We classify all
the unitary Cauchy fields. By analyzing the mode expansion on the unit sphere,
we show that all unitary Cauchy fields are free in the sense that their
correlation functions factorize on the 2-point function. We also discuss the
possibility of non-unitary Cauchy fields and classify them in d=3 and 4.Comment: 45 pages; v2: references adde
Curvature formula for the space of 2-d conformal field theories
We derive a formula for the curvature tensor of the natural Riemannian metric
on the space of two-dimensional conformal field theories and also a formula for
the curvature tensor of the space of boundary conformal field theories.Comment: 36 pages, 1 figure; v2 references adde
Ward Identity for Membranes
Ward identities in the case of scattering of antisymmetric three form RR
gauge fields off a D2-brane target has been studied in type-IIA theory.Comment: 10 pages, Revtex, Version to appear in Phys.Lett.
Entropy flow in near-critical quantum circuits
Near-critical quantum circuits are ideal physical systems for asymptotically
large-scale quantum computers, because their low energy collective excitations
evolve reversibly, effectively isolated from the environment. The design of
reversible computers is constrained by the laws governing entropy flow within
the computer. In near-critical quantum circuits, entropy flows as a locally
conserved quantum current, obeying circuit laws analogous to the electric
circuit laws. The quantum entropy current is just the energy current divided by
the temperature. A quantum circuit made from a near-critical system (of
conventional type) is described by a relativistic 1+1 dimensional relativistic
quantum field theory on the circuit. The universal properties of the
energy-momentum tensor constrain the entropy flow characteristics of the
circuit components: the entropic conductivity of the quantum wires and the
entropic admittance of the quantum circuit junctions. For example,
near-critical quantum wires are always resistanceless inductors for entropy. A
universal formula is derived for the entropic conductivity:
\sigma_S(\omega)=iv^{2}S/\omega T, where \omega is the frequency, T the
temperature, S the equilibrium entropy density and v the velocity of `light'.
The thermal conductivity is Real(T\sigma_S(\omega))=\pi v^{2}S\delta(\omega).
The thermal Drude weight is, universally, v^{2}S. This gives a way to measure
the entropy density directly.Comment: 2005 paper published 2017 in Kadanoff memorial issue of J Stat Phys
with revisions for clarity following referee's suggestions, arguments and
results unchanged, cross-posting now to quant-ph, 27 page
Automated clinical system for chromosome analysis
An automatic chromosome analysis system is provided wherein a suitably prepared slide with chromosome spreads thereon is placed on the stage of an automated microscope. The automated microscope stage is computer operated to move the slide to enable detection of chromosome spreads on the slide. The X and Y location of each chromosome spread that is detected is stored. The computer measures the chromosomes in a spread, classifies them by group or by type and also prepares a digital karyotype image. The computer system can also prepare a patient report summarizing the result of the analysis and listing suspected abnormalities
Renormalization Group Flows in Sigma--Models Coupled to Two--Dimensional Dynamical Gravity
We consider a bosonic \s--model coupled to two--dimensional gravity. In the
semiclassical limit, , we compute the gravity dressing of
the \b--functions at two--loop order in the matter fields. We find that the
corrections due to the presence of dynamical gravity are {\em not} expressible
simply in terms of a multiplicative factor as previously obtained at the
one--loop level. Our result indicates that the critical points of the theory
are nontrivially influenced and modified by the induced gravity.Comment: Latex file, 18 pages plus 7 figure
A Relation Between Gravity in --Dimensions and Pontrjagin Topological Invariant
A relation between the MacDowell-Mansouri theory of gravity and the
Pontrjagin toplogical invariant in dimensions is discussed. This
relation may be of especial interest in the quest of finding a mechanism to go
from non-dynamical to dynamical gravity.Comment: 9 pages, Te
Supersymmetric Extension of GCA in 2d
We derive the infinite dimensional Supersymmetric Galilean Conformal Algebra
(SGCA) in the case of two spacetime dimensions by performing group contraction
on 2d superconformal algebra. We also obtain the representations of the
generators in terms of superspace coordinates. Here we find realisations of the
SGCA by considering scaling limits of certain 2d SCFTs which are non-unitary
and have their left and right central charges become large in magnitude and
opposite in sign. We focus on the Neveu-Schwarz sector of the parent SCFTs and
develop, in parallel to the GCA studies recently in (arXiv:0912.1090), the
representation theory based on SGCA primaries, Ward identities for their
correlation functions and their descendants which are null states.Comment: La TeX file, 32 pages; v2: typos corrected, journal versio
New fields on super Riemann surfaces
A new -dimensional super vector bundle which exists on any super
Riemann surface is described. Cross-sections of this bundle provide a new class
of fields on a super Riemann surface which closely resemble holomorphic
functions on a super Riemann surface, but which (in contrast to the case with
holomorphic functions) form spaces which have a well defined dimension which
does not change as odd moduli become non-zero.Comment: 12pp, kcl-th-94-
- …