Romanian Academy

About: Romanian Academy is a archive organization based out in Bucharest, Romania. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 3662 authors who have published 10491 publications receiving 146447 citations. The organization is also known as: Academia Română & Societatea Literară Română.

Multiplicity of solutions for a class of quasilinear Kirchhoff system involving the fractional p-Laplacian

Abstract: In this paper, we investigate the multiplicity of solutions for a p-Kirchhoff system driven by a nonlocal integro-differential operator with zero Dirichlet boundary data. As a special case, we consider the following fractional p-Kirchhoff system {(∑i=1k[ui]s,pp)θ−1(−Δ)psuj(x)=λj|uj|q−2uj+∑i≠jβij|ui|m|uj|m−2ujin Ω,uj=0in RN\Ω, where , , , , is an open bounded subset of with Lipschitz boundary , N > ps with , is the fractional p-Laplacian, and for , . When and for all , two distinct solutions are obtained by using the Nehari manifold method. When and for all or and for all , the existence of infinitely many solutions is obtained by applying the symmetric mountain pass theorem. To our best knowledge, our results for the above system are new in the study of Kirchhoff problems.

A radiation transfer model for the Milky Way: I. Radiation fields and application to high-energy astrophysics

Abstract: We present a solution for the ultraviolet (UV) - submillimeter (submm) interstellar radiation fields (ISRFs) of the Milky Way, derived from modelling COBE, IRAS and Planck maps of the all-sky emission in the near-, mid-, far-infrared and submm The analysis uses the axisymmetric radiative transfer (RT) model that we have previously implemented to model the panchromatic spectral energy distributions (SEDs) of star forming galaxies in the nearby universe, but with a new methodology allowing for optimisation of the radial and vertical geometry of stellar emissivity and dust opacity, as deduced from the highly resolved emission seen from the vantage point of the Sun As such, this is the first self-consistent model of the broad-band continuum emission from the Milky Way In this paper, we present model predictions for the spatially integrated SED of the Milky Way as seen from the Sun, showing good agreement with the data, and give a detailed description of the solutions for the distribution of ISRFs, as well as their physical origin, throughout the volume of the galaxy We explore how the spatial and spectral distribution of our new predictions for the ISRF in the Milky Way affects the amplitude and spectral distribution of the gamma-rays produced via Inverse Compton scattering for cosmic ray electrons situated at different positions in the galaxy, as well as the attenuation of the gamma-rays due to interactions of the gamma-ray photons with photons of the ISRF We also compare and contrast our solutions for the ISRF with those incorporated in the GALPROP package used for modelling the high energy emission from cosmic rays in the Milky Way