Pauli-Villars Regularization in nonperturbative Hamiltonian approach on the Light Front

The advantage of Pauli-Villars regularization in quantum field theory quantized on the light front is explained. Simple examples of scalar $\lambda\varphi^4$ field theory and Yukawa-type model are used. We give also an example of nonperturbative calculation in the theory with Pauli-Villars fields, using for that a model of anharmonic oscillator modified by inclusion of ghost variables playing the role similar to Pauli-Villars fields.Comment: LaTeX, 10 pages, 2 figures. Article will be published in AIP Conference Proceedings, the final publication will be available at http://scitation.aip.org/content/aip/proceeding/aipc

Diagrammatic method for theory of magnetic and resistive properties of manganites

Effective field theory of magnetic and resistive properties of manganites with account of strong Hund exchange coupling and electron-phonon interactions has been evolved under the strong Hund coupling condition. In parallel with Lang-Firsov unitary transformation of the zeroth Hamiltonian, we have realized the diagonalization of Hund's Hamiltonian neglecting the upper triplet. The diagram techniques taking into account the quantum spin fluctuations of lower quintet and hole state with spin S=3/2 was developed. The magnetic structure of the ground state and an influence of electron-phonon interaction have been analyzed using the first nonvanishing approximation of perturbation theory. The calculated temperature dependence of resistivity agrees well with experimental data including these obtained in applied magnetic field.Comment: 44 pages, 14 figure

Chemistry-climate model SOCOL: a validation of the present-day climatology

International audienceIn this paper we document ''SOCOL'', a new chemistry-climate model, which has been ported for regular PCs and shows good wall-clock performance. An extensive validation of the model results against present-day climate obtained from observations and assimilation data sets shows that the model describes the climatological state of the atmosphere for the late 1990s with reasonable accuracy. The model has a significant temperature bias only in the upper stratosphere and near the tropopause in the tropics and high latitudes. The latter is the result of the rather low vertical resolution of the model near the tropopause. The former can be attributed to a crude representation of the radiation heating in the middle atmosphere. A comparison of the simulated and observed link between the tropical stratospheric structure and the strength of the polar vortex shows that in general, both observations and simulations reveal a higher temperature and ozone mixing ratio in the lower tropical stratosphere for the case with stronger Polar night jet (PNJ) as predicted by theoretical studies

ПРОБЛЕМЫ И ПЕРСПЕКТИВЫ РАЗВИТИЯ ЭЛЕКТРОННОГО ОБУЧЕНИЯ В РОССИИ

The article considers the changes occurred in the field of distance learning after endorsement of the new law on education and related regulations. The author analyzes the reasons, which prevent widespread development of e-learning and distance learning technologies. The paper puts forward the idea that many higher institutions are not interested in e-learning and distance learning development. The author makes conclusion that higher institutions are not sufficiently motivated to develop e-learning whereas external motivation doesn’t fulfil the requirements and interests of institutions.В статье рассматриваются изменения, происходящие в сфере дистанционного обучения после принятия новой редакции закона об образовании и связанных с ним нормативных документов. Анализируются причины, препятствующие широкому развитию электронного обучения, дистанционных образовательных технологий. В качестве рабочей гипотезы выдвигается утверждение, что в настоящее время многие вузы не заинтересованы в его полномасштабном внедрении. Сделан вывод о слабости внутренней мотивации вузов к развитию электронного обучения и о несоответствии внешней мотивации интересам большей части вузов

Chemistry-climate model SOCOL: a validation of the present-day climatology

In this paper we document 'SOCOL', a new chemistry-climate model, which has been ported for regular PCs and shows good wall-clock performance. An extensive validation of the model results against present-day climate data obtained from observations and assimilation data sets shows that the model describes the climatological state of the atmosphere for the late 1990s with reasonable accuracy. The model has a significant temperature bias only in the upper stratosphere and near the tropopause at high latitudes. The latter is the result of the rather low vertical resolution of the model near the tropopause. The former can be attributed to a crude representation of radiation heating in the middle atmosphere. A comparison of the simulated and observed link between the tropical stratospheric structure and the strength of the polar vortex shows that in general, both observations and simulations reveal a higher temperature and ozone mixing ratio in the lower tropical stratosphere for the case with stronger Polar night jet (PNJ) and slower Brewer-Dobson circulation as predicted by theoretical studies