scholarly journals On Products of Random Matrices

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 972 ◽  
Author(s):  
Natalia Amburg ◽  
Aleksander Orlov ◽  
Dmitry Vasiliev
Keyword(s):  
Random Matrices ◽  
Group Representation ◽  
Special Kind ◽  
Orientable Surface ◽  
Coupling Constants ◽  
Model Coupling ◽  
Hurwitz Numbers ◽  
Products Of Random Matrices ◽  
Free Parameters

We introduce a family of models, which we name matrix models associated with children’s drawings—the so-called dessin d’enfant. Dessins d’enfant are graphs of a special kind drawn on a closed connected orientable surface (in the sky). The vertices of such a graph are small disks that we call stars. We attach random matrices to the edges of the graph and get multimatrix models. Additionally, to the stars we attach source matrices. They play the role of free parameters or model coupling constants. The answers for our integrals are expressed through quantities that we call the “spectrum of stars”. The answers may also include some combinatorial numbers, such as Hurwitz numbers or characters from group representation theory.

A RELATIVISTIC EFFECTIVE MODEL WITH PARAMETERIZED COUPLINGS FOR NEUTRON STARS: THE ROLE OF ANTIKAON CONDENSATES

2011 ◽  
Vol 20 (supp02) ◽  
pp. 133-139
Author(s):  
ALEXANDRE MESQUITA ◽  
MOISÉS RAZEIRA ◽  
DIMITER HADJIMICHEF ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
ROSANA O. GOMES ◽  
...  
Keyword(s):  
Neutron Stars ◽  
Coupling Constants ◽  
Effective Model ◽  
Extended Model ◽  
Many Body ◽  
Parametric Dependence ◽  
Interaction Terms ◽  
Coupling Terms ◽  
Effective Models

We study the effects of antikaon condensates in neutron stars in the framework of a relativistic effective model with derivative couplings which includes genuine many-body forces simulated by nonlinear interaction terms involving scalar-isoscalar (σ, σ*), vector-isoscalar (ω, ɸ), vector-isovector (ϱ), scalar-isovector (δ) mesons. The effective model presented in this work has a philosophy quite similar to the original version of the model with parameterized couplings. But unlike that, in which the parametrization is directly inserted in the coupling constants of the Glendenning model, we present here a method for the derivation of the parametric dependence of the coupling terms, in a way that allows in one side to consistently justify this parametrization and in the other to extend in a coherent way the range of possibilities of parameterizations in effective models with derivative couplings. The extended model is then applied to the description of the mass of neutron stars.

scholarly journals Products of random matrices and derivatives on p.c.f. fractals

2008 ◽  
Vol 254 (5) ◽  
pp. 1188-1216 ◽  
Author(s):  
Anders Pelander ◽  
Alexander Teplyaev
Keyword(s):  
Random Matrices ◽  
Products Of Random Matrices

Simulations of electric field at the initiation altitudes of sprites and halos generated by the thundercloud charge structure and lightning channels of causative return strokes

2021 ◽  
Author(s):  
Petr Kaspar ◽  
Ivana Kolmasova ◽  
Ondrej Santolik ◽  
Martin Popek ◽  
Pavel Spurny ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Electric Field ◽  
Boundary Conditions ◽  
Free Space ◽  
Nonlinear Effects ◽  
Charge Structure ◽  
Transient Luminous Events ◽  
Lightning Channel ◽  
Free Parameters

<p><span>Sprites and halos are transient luminous events occurring above thunderclouds. They can be observed simultaneously or they can also appear individually. Circumstances leading to initiation of these events are still not completely understood. In order to clarify the role of lightning channels of causative lightning return strokes and the corresponding thundercloud charge structure, we have developed a new model of electric field amplitudes at halo/sprite altitudes. It consists of electrostatic and inductive components of the electromagnetic field generated by the lightning channel in free space at a height of 15 km. Above this altitude we solve Maxwell’s equations self-consistently including the nonlinear effects of heating and ionization/attachment of the electrons. At the same time, we investigate the role of a development of the thundercloud charge structure and related induced charges above the thundercloud. We show how these charges lead to the different distributions of the electric field at the initiation heights of the halos and sprites. We adjust free parameters of the model using observations of halos and sprites at the Nydek TLE observatory and using measurements of luminosity curves of the corresponding return strokes measured by an array of fast photometers. The latter measurements are also used to set the boundary conditions of the model.</span></p>

The Ideology of the Letter of Aristeas

1958 ◽  
Vol 51 (2) ◽  
pp. 59-85 ◽  
Author(s):  
V. Tcherikover
Keyword(s):  
Special Kind ◽  
General View ◽  
Self Defense ◽  
Greek World

Modern scholars commonly regard the “Letter of Aristeas” as a work typical of Jewish apologetics, aiming at self-defense and propaganda, and directed to the Greeks. Here are some instances illustrating this general view. In 1903 Friedländer wrote that the glorification of Judaism in the Letter was no more than self-defense, though “the book does not mention the antagonists of Judaism by name, nor does it admit that its intention is to refute direct attacks.” Stein sees in the Letter “a special kind of defense which practices diplomatic tactics,” and Tramontano also speaks of “an apologetic and propagandist tendency.” Vincent characterizes it as “a small apologetic novel written for the Egyptians” (i.e. the Greeks in Egypt). Pfeiffer says: “This fanciful story of the origin of the Septuagint is merely a pretext for defending Judaism against its heathen denigrators, for extolling its nobility and reasonableness, and for striving to convert Greek speaking Gentiles to it.” Schürer classes the Letter with a special kind of literature, “Jewish propaganda in Pagan disguise,” whose works are “directed to the pagan reader, in order to make propaganda for Judaism among the Gentiles.” Andrews, too, believes that the role of a Greek was assumed by Aristeas in order “to strengthen the force of the argument and commend it to non-Jewish readers.” And even Gutman, who rightly recognizes that the Letter sprang “from an inner need of the educated Jew,” sees in it “a strong means for making Jewish propaganda in the Greek world.”

scholarly journals The role of legal intellection in the lawmaking mechanism

2020 ◽  
Vol 6 (3) ◽  
pp. 67-73
Author(s):  
Ekaterina A. Petrova
Keyword(s):  
Special Kind ◽  
Thinking Style ◽  
Legal Traditions ◽  
Methods And Techniques ◽  
Legal Thinking ◽  
The Law ◽  
Legal Understanding ◽  
Law Making

The article gives the authors interpretation of legal intellection as a special kind of professional thinking. It is underlined that legal intellection is directly connected with lawmaking, since the law is a result of both of these processes. The main directions of its influence on the elements of the lawmaking mechanism are considered. The author interprets lawmaking mechanism as a set of interrelated and interdependent technical and legal elements that support law creation. These elements include the law-makers; law-making methods and techniques; the rules of claw; forms (sources) of law. It is noted that the lawyers belonging to a particular type of legal understanding determines the understanding of lawmaking process. The author analyzes the influence of legal thinking style, determined by legal traditions of various legal families, on application of various forms of law as a result of lawmaking. The examples from Russian and American legal reality are given. The problem of legal intellection level of lawmakers is discussed, because of its influence on the quality of sources of law. It is concluded that legal intellection as a special kind of professional thinking permeates all types of legal activities and, first of all, directly affects the specifics of the lawmaking mechanism, determining the content of its main elements: the law-makers are the holders of legal intellection; methods, techniques of law-making are determined by the stylistic features of legal thinking; the quality of the forms of law created in the lawmaking process directly depends on the legal thinking level of their creators.

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