We perform the study of stability Lorenz system by using Jacobi analysis, or Kosambi–Cartan–Chern (KCC) theory. The model plays an important role for understanding hydrodynamic instabilities and nature turbulence, also representing a nontrivial testing object studying nonlinear effects. KCC theory represents powerful mathematical method analysis dynamical systems. In this approach, we describe evolution in geometric terms, considering it as geodesic Finsler space. By associating connection...

If dark matter is composed of massive bosons, a Bose–Einstein condensation process must have occurred during the cosmological evolution. Therefore galactic may be in form condensate, characterized by strong self-interaction. We consider effects rotation on condensate halos, and we investigate how might influence their astrophysical properties. In order to describe use Gross–Pitaevskii equation, Thomas–Fermi approximation, which predicts polytropic equation state with index $$n=1$$ . By...

In the past few years, some studies claimed that annihilating dark matter with mass $\sim 10-100$ GeV can explain gamma-ray excess in our Galaxy. However, recent analyses of Fermi-LAT and radio observational data rule out possibility thermal relic $m \le 100$ for popular annihilation channels. By using new observed Andromeda galaxy, we existence 100-300$ ten The lower limits are improved to larger than 330 most conservative case, which is a times current best constraints. Moreover, these...

Abstract Radio data can give stringent constraints for annihilating dark matter. In general, radio observations detect very accurate flux density with high resolution and different frequencies nearby galaxies. We are able to obtain the as a function of distance from galactic center S ( r , ν ). this article, we demonstrate comprehensive analysis M33 galaxy, combining profile ) frequency spectrum get matter annihilation parameters. By analyzing archival obtained Effelsberg telescope, show...

We consider a description of the stochastic oscillations general relativistic accretion disks around compact astrophysical objects interacting with their external medium based on generalized Langevin equation colored noise and fluctuation–dissipation theorems. The former accounts for memory retarded effects frictional force. presence influences response disk to random interactions, it modifies dynamical behavior disk, as well energy dissipation processes. motion in vertical direction is...

We study the equations of motion massive and massless particles in Schwarzschild geometry general relativity by using Laplace-Adomian Decomposition Method, which proved to be extremely successful obtaining series solutions a wide range strongly nonlinear differential integral equations. After introducing formalism for derivation arbitrary spherically symmetric static geometries mathematical we obtain solution geodesics equation geometry. The truncated solution, containing only five terms,...

Some recent studies have examined the gamma-ray flux profile of our Galaxy to determine signal dark matter annihilation. However, results are controversial and no confirmation is obtained. In this article, we study radio density M31 galaxy show that it could manifest a possible By comparing likelihoods between archival observed data predicted contributed by stellar emission, can constrain relevant parameters. Specifically, for thermal annihilation cross section via $b\bar{b}$ channel,...

Abstract In the past decade, properties of annihilating dark matter models were examined by various kinds data, including data gamma-rays, radio waves, X-rays, positrons, electrons, antiprotons and neutrinos. particular, most studies focus on our Galaxy, nearby galaxies (e.g., M31 galaxy) or galaxy clusters Fornax cluster). this article, we examine archival continuum spectral a relatively high-redshift cluster (A697 cluster) to constrain matter. We find that leptophilic annihilation channels...

The Schrödinger–Newton system is a nonlinear obtained by coupling together the linear Schrödinger equation of quantum mechanics with Poisson Newtonian mechanics. In this work, we will investigate effects cosmological constant (dark energy or vacuum fluctuation) on system, modifying through addition new term. corresponding Schrödinger–Newton-[Formula: see text] cannot be solved exactly, and therefore for its study one must resort to either numerical semianalytical methods. order obtain...

The Adomian Decomposition Method (ADM) is a very effective approach for solving broad classes of nonlinear partial and ordinary differential equations, with important applications in different fields applied mathematics, engineering, physics biology. It the goal present paper to provide clear pedagogical introduction some its applications. In particular, we focus our attention number standard first-order equations (the linear, Bernoulli, Riccati, Abel) arbitrary coefficients, detail method...

Radio data can give stringent constraints for annihilating dark matter. In general, radio observations detect very accurate flux density with high resolution and different frequencies nearby galaxies. We are able to obtain the as a function of distance from galactic center $S(r,\nu)$. this article, we demonstrate comprehensive analysis M33 galaxy, combining profile $S(r)$ frequency spectrum $S(\nu)$ get matter annihilation parameters. By analyzing archival obtained Effelsberg telescope, show...

New physics beyond the Standard Model (BSM) with an extra neutral boson can be constrained from observation of SN1987A, since production this in a supernova (SN) could accelerate SN cooling and potentially lead to period neutrino burst incompatible observation. The constraint model is formulated by condition $L_{\rm NB}\leq 3\times 10^{52}$ erg/s according G. Raffelt NB}$ luminosity BSM boson. Computing above large coupling case, so-called trapping regime, non-trivial competition between...

New physics beyond the Standard Model (BSM) with an extra neutral boson can be constrained from observation of SN1987A, since productions this in a supernova (SN) could accelerate SN cooling and potentially lead to period neutrino burst incompatible observation. The constraint model is formulated by condition <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"...

We study the dynamics of vortices with arbitrary topological charges in weakly interacting Bose-Einstein condensates using Adomian Decomposition Method to solve nonlinear Gross-Pitaevskii equation polar coordinates. The solutions vortex are expressed form infinite power series. series representations compared exact numerical for uniform and harmonic potential, respectively. find that there is a good agreement between analytical results.

In the past decade, properties of annihilating dark matter models were examined by various kinds data, including data gamma rays, radio waves, X-ray, positrons, electrons, antiprotons and neutrinos. particular, most studies focus on our Galaxy, nearby galaxies (e.g. M31 galaxy) or galaxy clusters Fornax cluster). this article, we examine archival continuum spectral a relatively high-redshift cluster (A697 cluster) to constrain matter. We find that leptophilic annihilation channels ($e^+e^-$,...

We perform the study of stability Lorenz system by using Jacobi analysis, or Kosambi-Cartan-Chern (KCC) theory. The model plays an important role for understanding hydrodynamic instabilities and nature turbulence, also representing a non-trivial testing object studying non-linear effects. KCC theory represents powerful mathematical method analysis dynamical systems. In this approach we describe evolution in geometric terms, considering it as geodesic Finsler space. By associating connection...

The biharmonic equation, as well its nonlinear and inhomogeneous generalizations, plays an important role in engineering physics. In particular the focusing Schr\"{o}dinger standing wave solutions, have been intensively investigated. present paper we consider applications of Laplace-Adomian Adomian Decomposition Methods for obtaining semi-analytical solutions generalized equations type $\Delta ^{2}y+\alpha \Delta y+\omega y+b^{2}+g\left( y\right) =f$, where $\alpha $, $\omega $ $b$ are...

The flavor transition mechanisms of supernova neutrinos as they propagate outward from the deep inside a are yet to be determined. We study time-evolution patterns different neutrino flavors in various scenarios. With simulation data neutrinos, we calculate event rates at kinds detectors for Using calculated IBD and $\nu_e$Ar corresponding liquid scintillation argon detectors, ratios two cumulative time distribution up t = 100 ms Nakazato’s models with 13, 20, 30 M$_\odot$ progenitor mass....

Small radio telescope in 21cm was used for studying the partial solar eclipse, with magnitude 0.89, Hong Kong on 21st June, 2020. The SPIDER 300A designed and constructed by Radio2Space Company, Italy. Radio flux density time curves (light curve) a two-dimension mapping of eclipse is presented this paper. Standard data reduction methods were to obtain intensity curve. We also adopted semi-pipeline method same results as built-in software 300A. total found reduce maximum 55 +/- 5 percent,...