Prof.
Alexander Degtyarev
(Professor)
03/07/2017, 13:30
Stages of direct computational experiments in hydrodynamics based on tensor mathematics tools are represented by conditionally independent mathematical models for calculations separation in accordance with physical processes [1]. Continual stage of numerical modeling is constructed on a small time interval in a stationary grid space. Here coordination of continuity conditions and energy...
Prof.
Alexandr Egorov
(Institute of Mathematics National Academy of Sciences of Belarus)
03/07/2017, 13:45
The report is devoted to numerical evaluation of mathematical expectations of functionals defined on trajectories of stochastic processes. Our approach is to use quadrature formulas exact for functional polynomials of the trajectories of the process, as it was considered in [1,2]. Construction of this type of formulas is strongly dependent on way of giving the stochastic process. In [1,2] the...
Dr
Bijan Saha
(Laboratory of Information Technologies, Joint Institute for Nuclear Research)
03/07/2017, 14:00
Within the scope of non-diagonal Bianchi cosmological models we have
studied the role of spinor field in the evolution of the Universe.
Unlike in diagonal Bianchi models such as I, III, V, VI0
and VI where spinor field distribution along the main axis is
isotropic and becomes zero for linear spinor field, in case
(non-diagonal) Bianchi models such as II, VIII and IX, spinor
field...
Dr
Igor Bogolubsky
(JINR, Dubna)
03/07/2017, 14:15
We extract effective gluon mass from zero-momentum gluon correlators in the SU(2) lattice Quantum Chromodynamics (QCD). Lattice simulations of these correlators have been done both for (i) periodic and (ii) so-called "open" boundary conditions. We found that
the results for effective mass obtained in cases (i) and (ii) get closer when the lattice size increases. Nonzero effective gluon mass...
Prof.
Michal HNATIČ
(Institute of Physics, Pavol Jozef Safarik University, Kosice, Slovak Republic; Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research)
03/07/2017, 14:30
The first three corrections to the bound state energy, separation constants, and wavefunctions of hydrogen-like ion in the field of remote ($R \gg 1$) point charge are calculated by means of the modified perturbation theory. The consistent scheme for obtaining WKB expansions for solutions of the quasiangular equation in quantum mechanical two-Coulomb-centre problem $Z_1eZ_2$ is developed....
Dr
Alexandru Parvan
(IFIN-HH and JINR)
03/07/2017, 14:45
The exact analytical lattice results for the partition function of the free neutral scalar field in one spatial dimension in both the configuration and the momentum space were obtained in the framework of the path integral method. The symmetric square matrices of the bilinear forms on the vector space of fields in both configuration space and momentum space were found explicitly. The exact...
Mr
Martin Menkyna
(Slovak Academy of Sciences)
03/07/2017, 15:30
The field theoretic renormalization group and the operator product expansion are used for the investigation of the inertial-range anomalous scaling behaviour of the single-time correlation functions of the weak magnetic field within the framework of the compressible Kazantsev-Kraichnan rapid change model with spatial parity violation of the corresponding conductive turbulent environment....
Ms
Sarlota Birnsteinova
(Slovak)
03/07/2017, 15:45
Critical behaviour of directed bond percolation is studied in presence of an advective velocity field [1,2]. The velocity field is modeled by Kraichnan ensemble [3]: time-decorrelated compressible Gaussian velocity field. The model is studied by means of field-theoretic approach. Renormalization group (RG) method is used in order to analyse asymptotic large-scale behaviour of the model near...
Mr
Lukas Mizisin
(JINR Dubna, Pavol Josef Safarik University in Kosice)
03/07/2017, 16:00
Universal quantities (anomalous dimensions and critical exponents) of directed bond percolation are calculated by the renormalization group method in higher order perturbation theory. We put forward a renormalization procedure for a numerical calculation in which the quantities are expressed in terms of irreducible renormalized Feynman diagrams. The procedure is based on the perturbative...
Dr
Nugzar Makhaldiani
(JINR)
03/07/2017, 16:15
Concise introduction in RD and GAF with some applications.
Mr
Artem Bekzhanov
(JINR, BLTP), Dr
Serge Bondarenko
(JINR)
03/07/2017, 16:30
The method of construction of bound systems (deuteron, pion) based on the separable kernels of interaction is discussed. Also the work describes а way of studying the EM characteristics of such the systems, including elastic form factors. The questions of gauge-invarience are discussed. Comparison with the experimental data is carried out.
Prof.
Michal Hnatič
(Department of Theoretical Physics and Astrophysics, Faculty of Science, P.J. Safarik University, Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research)
03/07/2017, 16:45
Non- perturbative Renormalization Group ( NPRG ) technique is applied to a stochastical model of non-conserved scalar order parameter near its critical point, subject to turbulent advection .
The compressible advecting flow is modelled by a random Gaussian velocity field with zero mean and correlation function $\langle \upsilon_j \, \upsilon_i \rangle \sim
(P_{j i}^{\perp} + \alpha...
