18,244 research outputs found
Algebraic Structure in 0<c<1 Open-Closed String Field Theories
We apply stochastic quantization method to Kostov's matrix-vector models for
the second quantization of orientable strings with Chan-Paton like factors,
including both open and closed strings. The Fokker-Planck hamiltonian deduces
an orientable open-closed string field theory at the double scaling limit.
There appears an algebraic structure in the continuum F-P hamiltonian including
a Virasoro algebra and a SU(r) current algebra.Comment: LaTeX 9 page
Stochastic gauge fixing for N = 1 supersymmetric Yang-Mills theory
The gauge fixing procedure for N=1 supersymmetric Yang-Mills theory (SYM) is
proposed in the context of the stochastic quantization method (SQM). The
stochastic gauge fixing, which was formulated by Zwanziger for Yang-Mills
theory, is extended to SYM_4 in the superfield formalism by introducing a
chiral and an anti-chiral superfield as the gauge fixing functions. It is shown
that SQM with the stochastic gauge fixing reproduces the probability
distribution of SYM_4, defined by the Faddeev-Popov prescription, in the
equilibrium limit with an appropriate choice of the stochastic gauge fixing
functions. We also show that the BRST symmetry of the corresponding stochastic
action and the power counting argument in the superfield formalism ensure the
renormalizability of SYM_4 in this context.Comment: 35 pages, no figures, published version in Prog. Theor. Phy
Lattice Quantum Gravity from Stochastic 3-Geometries
I propose the Langevin equation for 3-geometries in the Ashtekar's formalism
to describe 4D Euclidean quantum gravity, in the sense that the corresponding
Fokker-Planck hamiltonian recovers the hamiltonian in 4D quantum gravity
exactly. The stochastic time corresponds to the Euclidean time in the gauge,
N=1 and . In this approach, the time evolution in 4D quantum gravity is
understood as a stochastic process where the quantum fluctuation of ` ` triad
\rq\rq is characterized by the curvature at the one unit time step before. The
lattice regularization of 4D quantum gravity is presented in this context.Comment: Latex 13 pages, some references are adde
Comment on Geometric Interpretation of Ito Calculus on the Lattice
A covariant nature of the Langevin equation in Ito calculus is clarified in
applying stochastic quantization method to U(N) and SU(N) lattice gauge
theories. The stochastic process is expressed in a manifestly general
coordinate covariant form as a collective field theory on the group manifold. A
geometric interpretation is given for the Langevin equation and the
corresponding Fokker-Planck equation in the sense of Ito.Comment: 9 page
Derivation of Superconformal Anomaly without Ghosts in N = 1 SYM_4
The anomalous Ward-Takahashi identity for the superconformal symmetry in the
four-dimensional N=1 supersymmetric Yang-Mills theory is studied in terms of
the stochastic quantization method (SQM). By applying the background field
method to the SQM approach, we derive the superconformal anomaly in the
one-loop approximation and show that the supersymmetric stochastic gauge fixing
term does not contribute to the anomaly.Comment: 14 pages, published version in Prog. Theor. Phy
MHOST: An efficient finite element program for inelastic analysis of solids and structures
An efficient finite element program for 3-D inelastic analysis of gas turbine hot section components was constructed and validated. A novel mixed iterative solution strategy is derived from the augmented Hu-Washizu variational principle in order to nodally interpolate coordinates, displacements, deformation, strains, stresses and material properties. A series of increasingly sophisticated material models incorporated in MHOST include elasticity, secant plasticity, infinitesimal and finite deformation plasticity, creep and unified viscoplastic constitutive model proposed by Walker. A library of high performance elements is built into this computer program utilizing the concepts of selective reduced integrations and independent strain interpolations. A family of efficient solution algorithms is implemented in MHOST for linear and nonlinear equation solution including the classical Newton-Raphson, modified, quasi and secant Newton methods with optional line search and the conjugate gradient method
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