800 research outputs found
Quasi-local Update Algorithms for Numerical Simulations of d=3 SU(2) LGT in the Dual Formulation
In the dual formulation of d=3 SU(2) LGT, the link variables are group
representations and valid configurations are those satisfying a number of
triangle inequalities. In \cite{lat99} algorithms for local updates that
automatically respect these constraints were described. It was also pointed out
there that these local updates were not ergodic. In this presentation, we
describe two different quasi-local updating algorithms which, in conjunction
with the local updates, appear to be ergodic.Comment: LATTICE2000(Topics in Gauge Theories),5 pages,5 figures,LaTe
The generalized no-ghost theorem for N=2 SUSY critical strings
We prove the no-ghost theorem for the N=2 SUSY strings in (2,2) dimensional
flat Minkowski space. We propose a generalization of this theorem for an
arbitrary geometry of the N=2 SUSY string theory taking advantage of the N=4
SCA generators present in this model. Physical states are found to be the
highest weight states of the N=4 SCA.Comment: 13
Current Status of the Numerical Simulations of d=3 SU(2) Lattice Gauge Theory in the Dual Formulation
We have continued our systematic investigations of the numerical simulations
of lattice gauge theories in the dual formulation. These include: i) a more
practical implementation of the quasi-local updating technique, ii) a thorough
investigation of the sign problem, iii) issues related to the ergodicity of the
various update algorithms, iv) a novel way of measuring conventional
observables like plaquette in the dual formalism and v) investigations of
thermalisation. While the dual formulation holds out a lot of promises in
principle, there are still some ways to go before it can be made into an
attractive alternative lattice formulation.Comment: LATTICE2000(Topics in Gauge Theories),5 pages,3
figures,LaTex(espcrc2.sty
Peritoneal Dialysis for Chronic Congestive Heart Failure
Maladaptive responses between a failing heart and the kidneys ultimately lead to permanent chronic kidney disease, referred to as cardiorenal syndrome type 2. In this narrative review, we discuss the pathophysiological pathways in the progression of cardiorenal failure and review the current evidence on peritoneal dialysis as a treatment strategy in cardiorenal syndrome type 2. A patient with heart failure can present with clinical symptoms related to venous congestion even in the absence of end-stage renal disease. Diuretics remain the cornerstone for the treatment of fluid overload related to heart failure. However, with chronic use, diuretic resistance can supervene. When medical therapy is no longer able to relieve congestive symptoms, ultrafiltration might be needed. Patients with heart failure tolerate well the gentle rate of fluid removal through peritoneal dialysis. Recent publications suggest a positive impact of starting peritoneal dialysis in patients with cardiorenal syndrome type 2 on the hospitalisation rate, functional status and quality of life
Quantum particle on hyperboloid
We present quantization of particle dynamics on one-sheet hyperboloid
embedded in three dimensional Minkowski space. Taking account of all global
symmetries enables unique quantization. Making use of topology of canonical
variables not only simplifies calculations but also gives proper framework for
analysis.Comment: 7 pages, no figures, revtex
Cryoablation of Small Renal Tumors in Patients with Solitary Kidneys: Initial Experience
Introduction. The purpose of this study was to evaluate the role of renal cryoablation in patients with solitary kidneys with the goals of tumor destruction and maximal renal parenchymal preservation. Methods. Eleven patients with single tumors were treated with cryoablation, of which 10 patients had solitary kidneys and 1 had a nonfunctioning contralateral kidney. All procedures were performed via an open extraperitoneal approach; ten tumors were treated with in-situ cryoablation and 1 tumor was treated with cryo-assisted partial nephrectomy. Results. Cryoablation was successfully performed without any preoperative complications. Mean patient age was 62.4 years (range 49â79), tumor location included: 6 (upper pole), 2 (mid-kidney), 3 (lower pole). The mean and median tumor size was 2.6 cm and 2.8 cm (range 1.2â4.3 cm), mean operative time 205 minutes (range 180â270 minutes), blood loss 98.5 ml (range 40â250 ml), and hospitalization 4.6 days (range 3â8 days). Creatinine values included: preoperative 1.43 mg/dL (range 1.2â1.9), postoperative 1.67 mg/dL (range 1.5â2.5), and nadir 1.57 mg/dL (range 1.3â2.1). All patients were followed postoperatively with magnetic resonance imaging for surveillance. At a median follow-up of 43 months, 9 patients had no evidence of recurrence, 1 patient has an enhancing indeterminate area, and 1 patient was lost to follow-up. Conclusion. Intermediate-term results suggest that renal cryoablation offers a feasible alternative for patients that require a maximal nephron-sparing effort with preservation of renal function and minimal risk of tumor recurrence
Semiclassical Time Evolution and Trace Formula for Relativistic Spin-1/2 Particles
We investigate the Dirac equation in the semiclassical limit \hbar --> 0. A
semiclassical propagator and a trace formula are derived and are shown to be
determined by the classical orbits of a relativistic point particle. In
addition, two phase factors enter, one of which can be calculated from the
Thomas precession of a classical spin transported along the particle orbits.
For the second factor we provide an interpretation in terms of dynamical and
geometric phases.Comment: 8 pages, no figure
Interactions in the SL(2,R)/U(1) Black Hole Background
We calculate two- and three-point tachyon amplitudes of the SL(2,R)/U(1)
two-dimensional Euclidean black hole for spherical topologies in the continuum
approach proposed by Bershadsky and Kutasov. We find an interesting relation to
the tachyon scattering amplitudes of standard non-critical string theory.Comment: 34 pages, CERN-TH.6976/9
Semiclassical limits for the QCD Dirac operator
We identify three semiclassical parameters in the QCD Dirac operator. Mutual
coupling of the different types of degrees of freedom (translational, colour
and spin) depends on how the semiclassical limit is taken. We discuss various
semiclassical limits and their potential to describe spectrum and spectral
statistics of the QCD Dirac operator close to zero virtuality.Comment: 34 pages, 1 figur
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