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We present a general approach to the derivation of the effective anisotropy field which determines the dynamical behaviour of magnetic spins according to the Landau-Lifshitz-Gilbert equation. The approach is based on the gradient in…

An analytical approach to the one-dimensional spinless Holstein model is proposed, which is valid at finite charge-carrier concentrations. Spectral functions of charge carriers are computed on the basis of self-energy calculations. A…

Strongly Correlated Electrons · Physics 2007-05-23 J. Loos , M. Hohenadler , H. Fehske

The formalism of the linear response for the Skyrme energy density functional including tensor terms derived in articles [1,2] for nuclear matter is applied here to the case of pure neutron matter. As in article [2] we present analytical…

Nuclear Theory · Physics 2015-06-05 A. Pastore , M. Martini , V. Buridon , D. Davesne , K. Bennaceur , J. Meyer

Formulas for the corrections to the energy levels and wave functions of a spin-zero particle bound in a strong field are derived. General case of the sum of a Lorentz-scalar potential and zero component of a Lorentz-vector potential is…

Atomic Physics · Physics 2009-11-11 R. N. Lee , A. I. Milstein , S. G. Karshenboim

The Dirac equation is considered in Schwarzschild black hole immersed in an electromagnetic universe with charge coupling. The equations of the charged spin-1/2 particle is separated into radial and angular equations by adopting the…

General Relativity and Quantum Cosmology · Physics 2019-07-19 Ahmad Al-Badawi

The recent compelling observation of the nanohertz stochastic gravitational wave background has brought to light a new galactic arena to test gravity. In this paper, we derive a formula for the most general expression of the stochastic…

General Relativity and Quantum Cosmology · Physics 2024-04-12 Reginald Christian Bernardo , Guo-Chin Liu , Kin-Wang Ng

Polarisation states are described by spin expectation values, known as Stokes parameters, whose trajectories in a rotationally symmetric system form a sphere named after Poincar\'e. Here, we show that the trajectories of broken rotational…

Optics · Physics 2024-06-07 Shinichi Saito

We investigate the feasibility of the macrospin approximation to account for the actual shape of soft magnetic nanoparticles (MNPs) with realistic geometries. Specifically focusing on magnetite, we use the superellipsoidal parametrisation…

Materials Science · Physics 2026-04-23 Iago López-Vázquez , Òscar Iglesias , David Serantes

Aims. We aim to characterise the magnetism of a large fraction of the north polar region close to a maximum of activity, when the polar regions are reversing their dominant polarity. Methods. We make use of full spectropolarimetric data…

Solar and Stellar Astrophysics · Physics 2020-04-08 A. Pastor Yabar , M. J. Martínez González , M. Collados

In Papers I-III [arXiv:2210.10435, arXiv:2210.11085, arXiv:2304.13304], we use the flat-sky and distant-observer approximations to develop a formalism with which the correlation statistics of cosmological tensor fields are calculated by the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-23 Takahiko Matsubara

Relativistic structured spin-polarized (SSP) particle beams, characterized by polarization structures, are of critical importance in a wide range of applications, such as material properties investigation, imaging, and information storage.…

Spin-polarized neutron matter is studied using chiral two- and three-body forces. We focus, in particular, on predictions of the energy per particle in ferromagnetic neutron matter at different orders of chiral effective field theory and…

Nuclear Theory · Physics 2015-12-09 F. Sammarruca , R. Machleidt , N. Kaiser

Linear polarized light has been used to view the solar corona for over 150 years. While the familiar Stokes representation for polarimetry is complete, it is best matched to a laboratory setting and therefore is not the most convenient…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Craig E. DeForest , Daniel B. Seaton , Matthew J. West

We present configurations of polarimeters which measure the three linear Stokes parameters of the Cosmic Microwave Background Radiation with a nearly diagonal error matrix, independent of the global orientation of the polarimeters in the…

Astrophysics · Physics 2011-05-23 F. Couchot , J. Delabrouille , J. Kaplan , B. Revenu

A discussion of polyhomogeneity (asymptotic expansions in terms of $1/r$ and $\ln r$) for zero-rest-mass fields and gravity and its relation with the Newman-Penrose (NP) constants is given. It is shown that for spin-$s$ zero-rest-mass…

General Relativity and Quantum Cosmology · Physics 2014-11-17 J. A. Valiente-Kroon

The numerical computation of reliable and accurate Stokes profiles is of great relevance in solar physics. In the synthesis process, many actors play a relevant role: among them the formal solver, the discrete atmospheric model, and the…

Solar and Stellar Astrophysics · Physics 2018-09-19 Gioele Janett , Oskar Steiner , Luca Belluzzi

The soft limits of scattering amplitudes have been extensively studied due to their essential role in the computation of physical observables in collider physics. The universal factorisation that occurs in these kinematic limits has been…

High Energy Physics - Theory · Physics 2022-12-14 Tristan McLoughlin , Andrea Puhm , Ana-Maria Raclariu

Density functional theory is a preferred microscopic method for calculation of nuclear properties over the whole nuclear chart. Besides ground-state properties, which are calculated by Hartree-Fock theory, nuclear excitations can be…

Nuclear Theory · Physics 2020-06-02 Anton Repko

Spin polarizabilities of the nucleon are discussed in the framework of fixed-t and backward-angle dispersion relations, chiral perturbation theory, and the non-relativistic quark model. Calculations with the dispersion relations generally…

Nuclear Theory · Physics 2007-05-23 A. I. L'vov

This paper discusses sparse isotropic regularization for a random field on the unit sphere $\mathbb{S}^2$ in $\mathbb{R}^{3}$, where the field is expanded in terms of a spherical harmonic basis. A key feature is that the norm used in the…

Numerical Analysis · Mathematics 2018-01-11 Quoc T. Le Gia , Ian H. Sloan , Robert S. Womersley , Yu Guang Wang