اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدCalculation of the electromagnetic scattering by non-spherical particles based on the volume integral equation in the spherical wave function basis
121
0
0.0
(
0
)
تأليف
Alexey A. Shcherbakov
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The paper presents a method for calculation of non-spherical particle T-matrices based on the volume integral equation and the spherical vector wave function basis, and relies on the Generalized Source Method rationale. The developed method appears to be close to the invariant imbedding approach, and the derivations aims at intuitive demonstration of the calculation scheme. In parallel calculation of single columns of T-matrix is considered in detail, and it is shown that this way not only has a promising potential of parallelization but also yields an almost zero power balance for purely dielectric particles.
قيم البحث
اقرأ أيضاً
The computation of light scattering by the superposition T-matrix scheme has been so far restricted to systems made of particles that are either sparsely distributed or of near-spherical shape. In this work, we extend the range of applicability of th
e T-matrix method by accounting for the coupling of scattered fields between highly non-spherical particles in close vicinity. This is achieved using an alternative formulation of the translation operator for spherical vector wave functions, based on a plane wave expansion of the particles scattered electromagnetic field. The accuracy and versatility of the present approach is demonstrated by simulating arbitrarily oriented and densely packed spheroids, for both, dielectric and metallic particles.
Simple analytical formulae, directly relating the experimental geometry and sample orientation to the measured R(M)XS scattered intensity are very useful to design experiments and analyse data. Such formulae can be obtained by the contraction of an e
xpression containing the polarisations and crystal field tensors, and where the magnetisation vector acts as a rotation derivativecite{mirone}. The result of a contraction contains a scalar product of (rotated) polarisation vectors and the crystal field axis. The contraction rules give rise to combinatorial algorithms which can be efficiently treated by computers. In this work we provide and discuss a concise Mathematica code along with a few example applications to non-centrosymmetric magnetic systems.
For a rational function f we consider the norm of the derivative with respect to the spherical metric and denote by K(f) the supremum of this norm. We give estimates of this quantity K(f) both for an individual function and for sequences of iterates.
Critical overdensity $delta_c$ is a key concept in estimating the number count of halos for different redshift and halo-mass bins, and therefore, it is a powerful tool to compare cosmological models to observations. There are currently two different
prescriptions in the literature for its calculation, namely, the differential-radius and the constant-infinity methods. In this work we show that the latter yields precise results {it only} if we are careful in the definition of the so-called numerical infinities. Although the subtleties we point out are crucial ingredients for an accurate determination of $delta_c$ both in general relativity and in any other gravity theory, we focus on $f(R)$ modified-gravity models in the metric approach; in particular, we use the so-called large ($F=1/3$) and small-field ($F=0$) limits. For both of them, we calculate the relative errors (between our method and the others) in the critical density $delta_c$, in the comoving number density of halos per logarithmic mass interval $n_{ln M}$ and in the number of clusters at a given redshift in a given mass bin $N_{rm bin}$, as functions of the redshift. We have also derived an analytical expression for the density contrast in the linear regime as a function of the collapse redshift $z_c$ and $Omega_{m0}$ for any $F$.
In this paper we investigate the $L^p$ boundedness of the lacunary maximal function $ M_{Ha}^{lac} $ associated to the spherical means $ A_r f$ taken over Koranyi spheres on the Heisenberg group. Closely following an approach used by M. Lacey in the
Euclidean case, we obtain sparse bounds for these maximal functions leading to new unweighted and weighted estimates. The key ingredients in the proof are the $L^p$ improving property of the operator $A_rf$ and a continuity property of the difference $A_rf-tau_y A_rf$, where $tau_yf(x)=f(xy^{-1})$ is the right translation operator.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
