33,425 research outputs found
Spectral flow invariants and twisted cyclic theory from the Haar state on SU_q(2)
In [CPR2], we presented a K-theoretic approach to finding invariants of
algebras with no non-trivial traces. This paper presents a new example that is
more typical of the generic situation. This is the case of an algebra that
admits only non-faithful traces, namely SU_q(2), and also KMS states. Our main
results are index theorems (which calculate spectral flow), one using ordinary
cyclic cohomology and the other using twisted cyclic cohomology, where the
twisting comes from the generator of the modular group of the Haar state. In
contrast to the Cuntz algebras studied in [CPR2], the computations are
considerably more complex and interesting, because there are nontrivial `eta'
contributions to this index.Comment: 25 pages, 1 figur
The Quantum Dynamics of Heterotic Vortex Strings
We study the quantum dynamics of vortex strings in N=1 SQCD with U(N_c) gauge
group and N_f=N_c quarks. The classical worldsheet of the string has N=(0,2)
supersymmetry, but this is broken by quantum effects. We show how the pattern
of supersymmetry breaking and restoration on the worldsheet captures the
quantum dynamics of the underlying 4d theory. We also find qualitative matching
of the meson spectrum in 4d and the spectrum on the worldsheet.Comment: 13 page
Heterotic Vortex Strings
We determine the low-energy N=(0,2) worldsheet dynamics of vortex strings in
a large class of non-Abelian N=1 supersymmetric gauge theories.Comment: 44 pages, 3 figures. v2: typos corrected, reference adde
Lunar landing module reflectivity model
Lunar landing module reflectivity model based on Surveyor and Orbiter photographs of lunar craters, hills, and boulder
Probable deviations in altitude reading given by the LM altimeter for the most rough surface along a certain given trajectory
Random noise calculations in altitude reading of lunar module altimeter for rough surfaces targe
Livestock Disease Indemnity Design When Biosecurity Externalities Exist
Agricultural and Food Policy, Farm Management,
Superconformal Vortex Strings
We study the low-energy dynamics of semi-classical vortex strings living
above Argyres-Douglas superconformal field theories. The worldsheet theory of
the string is shown to be a deformation of the CP^N model which flows in the
infra-red to a superconformal minimal model. The scaling dimensions of chiral
primary operators are determined and the dimensions of the associated relevant
perturbations on the worldsheet and in the four dimensional bulk are found to
agree. The vortex string thereby provides a map between the A-series of N=2
superconformal theories in two and four dimensions.Comment: 22 pages. v2: change to introductio
Overbarrier Resonances as Solutions of Set Inhomogeneous Schr\"{o}dinger Equations
In the paper the Schr\"odinger equation for quasibound resonance state with
complex energy is considered. The system of inhomogeneous differential
equations is obtained for the real and imaginary parts of wave function. On the
base of known solution of corresponding homogeneous equation, the inhomogeneus
system is solved with help of iteration procedure. The single-particle neutron
-state in the Woods - Saxon potential is analyzed for nucleus.Comment: 19 pages, 3 figure
Extended Variational Cluster Approximation
The variational cluster approximation (VCA) proposed by M. Potthoff {\it et
al.} [Phys. Rev. Lett. {\bf 91}, 206402 (2003)] is extended to electron or spin
systems with nonlocal interactions. By introducing more than one source field
in the action and employing the Legendre transformation, we derive a
generalized self-energy functional with stationary properties. Applying this
functional to a proper reference system, we construct the extended VCA (EVCA).
In the limit of continuous degrees of freedom for the reference system, EVCA
can recover the cluster extension of the extended dynamical mean-field theory
(EDMFT). For a system with correlated hopping, the EVCA recovers the cluster
extension of the dynamical mean-field theory for correlated hopping. Using a
discrete reference system composed of decoupled three-site single impurities,
we test the theory for the extended Hubbard model. Quantitatively good results
as compared with EDMFT are obtained. We also propose VCA (EVCA) based on
clusters with periodic boundary conditions. It has the (extended) dynamical
cluster approximation as the continuous limit. A number of related issues are
discussed.Comment: 23 pages, 5 figures, statements about DCA corrected; published
versio
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