Babajanov B.A., Azamatov A.Sh. «Integration of the Kaup–Boussinesq system with a self-consistent source via inverse scattering method» Вестник Удмуртского университета: Математика. Механика. Компьютерные науки, 22, № 2, с. 153-170 (2022)

Рассматривается система Каупа–Буссинеска с самосогласованным источником. Показано, что система Каупа–Буссинеска с самосогласованным источником может быть проинтегрирована методом обратной задачи рассеяния. Для решения рассматриваемой задачи используются прямая и обратная задачи рассеяния уравнения Штурма–Лиувилля с потенциалом, зависящим от энергии. Определена временная эволюция данных рассеяния для уравнения Штурма–Лиувилля с энергозависимыми потенциалами, связанными с решением системы Каупа–Буссинеска с самосогласованным источником. Полученные равенства полностью определяют данные рассеяния при любом t, что позволяет применить метод обратной задачи рассеяния для решения задачи Коши для системы Каупа–Буссинеска с самосогласованным источником. Ключевые слова: нелинейное уравнение солитона, система Каупа–Буссинеска, самосогласованный источник, метод обратного рассеяния, квадратичный пучок уравнений Штурма–Лиувилля.

Feckan Michal, Urazboev Gayrat, Baltaeva Iroda «Inverse scattering and loaded modified Korteweg–de Vries equation» Журнал Сибирского Федерального университета. Математика и физика, 15, № 2, с. 178-185 (2022)

Рассматривается задача Коши для нагруженного модифицированного уравнения Кортевега–де Фриза в классе «быстроубывающих» функций. Основной результат настоящей работы представляет собой теорему об эволюции данных рассеяния оператора Дирака, потенциал которого является решением нагруженного модифицированного уравнения Кортевега-де Фриза. Полученные равенства позволяют применить метод обратной задачи рассеяния для решения задачи Коши для нагруженного модифицированного уравнения Кортевега–де Фриза.

Bernabei R., Belli P., Bussolot «Recent results from DAMA/LIBRA and comparisons» Вестник Московского университета. Серия 3: Физика. Астрономия, № 2, http://vmu.phys.msu.ru/toc/2022/2 (2022)

The long-standing model-independent annual modulation effect measured by DAMA deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. using different experi- mental configurations is summarized also including the results of two new annual cycles collected by DAMA/LIBRA-phase2; the total exposure of DAMA/LIBRA–phase2 over 8 annual cycles is 1.53 ton·yr. The evidence of a signal that meets all the requirements of the model independent Dark Matter (DM) annual modulation signature is further confirmed at 11.8 σ C.L. in the energy region (1–6) keV. In the energy region between 2 and 6 keV, where data are also available from DAMA/NaI and DAMA/LIBRA–phase1, the achieved C.L. for the full exposure (2.86 ton·yr) is 13.7 σ.

Belli P., Bernabei R., Caracciolo V. «Crystal scintillators for the Dark Matter directionality approach» Вестник Московского университета. Серия 3: Физика. Астрономия, № 2, http://vmu.phys.msu.ru/toc/2022/2 (2022)

Low background anisotropic detectors can offer a unique way to study those Dark Matter (DM) candidate particles able to induce nuclear recoils through the directionality technique. This approach is based on studying the correlation between the nuclear recoils' direction and the Earth motion in the galactic rest frame. Thanks to the anisotropic features of such detectors, a signal, induced by the DM candidates, is expected to change with a particular behaviour as a function of the sidereal time. The ZnWO4 has unique features and it is an excellent candidate for the purposes. Both the light output and the scintillation pulse shape depend on the impinging direction of heavy particles (p, nuclear recoils, etc.) with respect to the crystal axes and can supply two independent modes to study the directionality and to discriminate the radiation (that does not give rise to any anisotropic effects). In this work, the measurements to study the anisotropic response of a ZnWO4 scintillation detector to particles and to nuclear recoils, induced by neutron scattering, are brie γ summarised.

Berdugo J. «Latest results of the Alpha Magnetic Spectrometer on the International Space Station» Вестник Московского университета. Серия 3: Физика. Астрономия, № 2, http://vmu.phys.msu.ru/toc/2022/2 (2022)

The Alpha Magnetic Spectrometer (AMS) is a general-purpose high-energy particle detector that was deployed to the International Space Station (ISS) on May 19, 2011 to perform a unique long duration mission of fundamental physics research from space. Among the scientific goals of AMS are the search for Dark Matter and Antimatter, the study of the propagation of cosmic rays and the exploration of new scientific phenomena that cannot be achieved on ground-based experiments. After ten years of operation in space, AMS has collected more than 180 billion cosmic ray events and provided accurate measurements of electrons, positrons, protons, antiprotons, and nuclei with energies of several TeV during nearly a complete solar cycle

Bernabei R., Belli P., Bussolot «Recent results from DAMA/LIBRA and comparisons» Вестник Московского университета. Серия 3: Физика. Астрономия, № 2, http://vmu.phys.msu.ru/toc/2022/2 (2022)

The long-standing model-independent annual modulation effect measured by DAMA deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. using different experi- mental configurations is summarized also including the results of two new annual cycles collected by DAMA/LIBRA-phase2; the total exposure of DAMA/LIBRA–phase2 over 8 annual cycles is 1.53 ton·yr. The evidence of a signal that meets all the requirements of the model independent Dark Matter (DM) annual modulation signature is further confirmed at 11.8 σ C.L. in the energy region (1–6) keV. In the energy region between 2 and 6 keV, where data are also available from DAMA/NaI and DAMA/LIBRA–phase1, the achieved C.L. for the full exposure (2.86 ton·yr) is 13.7 σ.

Belli P., Bernabei R., Caracciolo V. «Crystal scintillators for the Dark Matter directionality approach» Вестник Московского университета. Серия 3: Физика. Астрономия, № 2, http://vmu.phys.msu.ru/toc/2022/2 (2022)

Low background anisotropic detectors can offer a unique way to study those Dark Matter (DM) candidate particles able to induce nuclear recoils through the directionality technique. This approach is based on studying the correlation between the nuclear recoils' direction and the Earth motion in the galactic rest frame. Thanks to the anisotropic features of such detectors, a signal, induced by the DM candidates, is expected to change with a particular behaviour as a function of the sidereal time. The ZnWO4 has unique features and it is an excellent candidate for the purposes. Both the light output and the scintillation pulse shape depend on the impinging direction of heavy particles (p, nuclear recoils, etc.) with respect to the crystal axes and can supply two independent modes to study the directionality and to discriminate the radiation (that does not give rise to any anisotropic effects). In this work, the measurements to study the anisotropic response of a ZnWO4 scintillation detector to particles and to nuclear recoils, induced by neutron scattering, are brie γ summarised.

Zemlyanukhin A.I., Bochkarev A.V., Ratushny A.V., Chernenko A.V. «Generalized model of nonlinear elastic foundation and longitudinal waves in cylindrical shells» Известия Саратовского университета. Новая серия. Серия: Математика. Механика. Информатика, 22, № 2, с. 196-204 (2022)

Выведено неинтегрируемое квазигиперболическое уравнение шестого порядка, моделирующее осесимметричное распространение продольных волн вдоль образующей цилиндрической оболочки Кирхгофа–Лява, взаимодействующей с нелинейно-упругой средой. Введена в рассмотрение шестипараметрическая обобщенная модель нелинейно-упругой среды, сводящаяся в частных случаях к моделям Винклера, Пастернака и Хетеньи. Вывод уравнения осуществлен асимптотическим методом многих масштабов в предположении, что безразмерные параметры нелинейности, дисперсии и тонкостенности имеют одинаковый порядок малости. Использование введенной модели позволило выявить дополнительные высокочастотные и низкочастотную дисперсии, характеризующие реакцию внешней среды на изгиб и сдвиг. Показано, что для выявления нелинейных эффектов, компенсирующих дисперсию, необходимо использовать неклассические теории оболочек. Установлено, что модель Пастернака допускает «бездисперсионное» состояние, когда дисперсия, обусловленная инерцией нормального перемещения, компенсируется дисперсией, порождаемой реакцией нелинейно-упругого основания на сдвиг.

Brevik I., Timoshkin A.V. «Holographic description of the dissipative model of universe with curvature» Журнал экспериментальной и теоретической физики, 162, № 3, с. 373-376 (2022)

DOI: 10.31857/S0044451022090097

Busoni G. «Capture of Dark Matter in Neutron Stars» Вестник Московского университета. Серия 3: Физика. Астрономия, № 2, http://vmu.phys.msu.ru/toc/2022/2 (2022)

The extreme conditions in Neutron Stars make them ideal test facilities for fundamental inter- actions. A Neutron Star can capture Dark Matter via scattering. As a result of the scattering, Dark Matter kinetic energy is transferred to the star. An observational consequence of this can be the warming of old neutron stars to near-infrared temperatures. Different approximations or simplifications have been applied to previous analyses of the capture process. In this article, we summarise a significantly improved treatment of Dark Matter capture, which properly accounts for all relevant physical effects over a wide range of Dark Matter masses. Among them are gravitational focusing, a fully relativistic scattering treatment, Pauli blocking, neutron star opacity and multiple scattering effects. This paper cites general expressions that allow the capture rate to be computed numerically, and simplified expressions for particular types of interactions or mass regimes, which greatly increase the efficiency of computation. As a result of our method, we are able to model the scattering of Dark Matter from any neutron star constituent as well as the capture of Dark Matter in other compact objects. Our results are applied to scattering of Dark Matter from neutrons, protons, leptons and exotic baryons. For leptonic targets, we found that a relativistic description is essential. In our analysis of the capture of Dark Matter in Neutron Stars, we include two important effects that are generally ignored by most studies. Because the scattering of Dark Matter with nucleons in the star exhibits large momentum transfers, the nucleon structure must be considered via momentum-dependent hadronic form factors. Moreover, because of the extreme densities of matter inside Neutron Stars, we should consider nucleon interactions instead of assuming all nucleons are a perfect Fermi gas. Taking into account these effects results in a decrease of up to three orders of magnitude in the dark matter capture rate. The potential Neutron Star sensitivity to DM-lepton scattering cross sections is much greater than electron-recoil experiments, particularly in the sub-GeV regime, with a sensitivity to sub- MeV DM well beyond the reach of future terrestrial experiments. We also present results for DM- Baryon scatterings in Neutron Stars, where the sensitivity is expected to exceed that of current DD experiments for spin-dependent cases across the entire mass range, and for spin-independent cases across the high and low mass range.

Bernabei R., Belli P., Bussolot «Recent results from DAMA/LIBRA and comparisons» Вестник Московского университета. Серия 3: Физика. Астрономия, № 2, http://vmu.phys.msu.ru/toc/2022/2 (2022)

The long-standing model-independent annual modulation effect measured by DAMA deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. using different experi- mental configurations is summarized also including the results of two new annual cycles collected by DAMA/LIBRA-phase2; the total exposure of DAMA/LIBRA–phase2 over 8 annual cycles is 1.53 ton·yr. The evidence of a signal that meets all the requirements of the model independent Dark Matter (DM) annual modulation signature is further confirmed at 11.8 σ C.L. in the energy region (1–6) keV. In the energy region between 2 and 6 keV, where data are also available from DAMA/NaI and DAMA/LIBRA–phase1, the achieved C.L. for the full exposure (2.86 ton·yr) is 13.7 σ.

Molchanov A.M., Yanyshev D.S., Bykov L.V. «Numerical Investigation of a Supersonic Flow in the Near Wake Region of a Cylindrical Afterbody» Вестник МГТУ им. Н.Э. Баумана. Серия: Естественные науки, № 3, с. 86-95 (2022)

A computational study of a supersonic flow in the base region and the nearest wake of a cylindrical body moving at a supersonic speed have been carried out. A mathematical model of high-enthalpy flows is presented. In this case, the "prehistory" of the flow was taken into account, i.e., the configuration of the computational domain was as close as possible to the real one. The use of various turbulence models for calculating flow in the base region and the nearest wake was analyzed. The following turbulence models were considered: 1) the Spalart–Allmaras model; 2) SST model; 3) standard κ–ε model; 4) κ–ε model with compressibility correction; 5) κ–ε RNG (renormalized group) model; 6) κ–ε Realizable model; 7) standard Reynolds Stress (RS) model; 8) RS BSL (Reynolds stress baseline) model. Based on a comparison of the calculation results with experimental data, it is shown that: 1) when calculating the flow in the base region and in the wake of the vehicle, it is very important to take into account the "prehistory" of the flow, i.e., to calculate the flow around the entire vehicle; 2) the best match was obtained using Reynolds Stress models and the κ–ε RNG model