3,722 research outputs found
A Model of Interindustry Interaction in the USSR
A quantitative analysis of the development of interindustry flows in the Soviet economy showed that traditional input-output methods needed to be expanded and generalized for use in Soviet medium-term (5-7 year) planning. In particular, it is necessary to account for supply constraints on some products and relative surpluses of others. This paper describes a model which accounts for these influences, fits closely the development of the Soviet economy from 1950 to 1975, and can be and has been used in the exploratory stages of Soviet planning
Fake News as a Parasit of Social Media
The article is devoted to the problem of fake news, which is understood as fabricated for the discrediting of some person or organization of the message, designed to spread viral in social media. Disinformation is now similar to a virus, easily clinging to the reader and undermining the reputation of both the object of the information attack and the distribution channel itself.Статья посвящена проблеме фейковых новостей, которые понимаются как сфабрикованные для дискредитации какой-то персоны или организации сообщения, рассчитанные на вирусное распространение в социальных сетях. Дезинформация становится похожа на вирус, легко цепляясь к читателю и подрывая репутацию как объекта информационной атаки, так и самого канала распространения новости
Property for noncommutative universal lattices
We establish a new spectral criterion for Kazhdan's property which is
applicable to a large class of discrete groups defined by generators and
relations. As the main application, we prove property for the groups
, where and is an arbitrary finitely generated
associative ring. We also strengthen some of the results on property for
Kac-Moody groups from a paper of Dymara and Januszkiewicz (Invent. Math 150
(2002)).Comment: 47 pages; final versio
Theory of transient spectroscopy of multiple quantum well structures
A theory of the transient spectroscopy of quantum well (QW) structures under
a large applied bias is presented. An analytical model of the initial part of
the transient current is proposed. The time constant of the transient current
depends not only on the emission rate from the QWs, as is usually assumed, but
also on the subsequent carrier transport across QWs. Numerical simulation was
used to confirm the validity of the proposed model, and to study the transient
current on a larger time scale. It is shown that the transient current is
influenced by the nonuniform distribution of the electric field and related
effects, which results in a step-like behavior of the current. A procedure of
extraction of the QW emission time from the transient spectroscopy experiments
is suggested.Comment: 5 pages, 4 figures, to be published in J. Appl. Phy
Noiseless Collective Motion out of Noisy Chaos
We consider the effect of microscopic external noise on the collective motion
of a globally coupled map in fully desynchronized states. Without the external
noise a macroscopic variable shows high-dimensional chaos distinguishable from
random motion. With the increase of external noise intensity, the collective
motion is successively simplified. The number of effective degrees of freedom
in the collective motion is found to decrease as with the
external noise variance . It is shown how the microscopic noise can
suppress the number of degrees of freedom at a macroscopic level.Comment: 9 pages RevTex file and 4 postscript figure
Collective motions in globally coupled tent maps with stochastic updating
We study a generalization of globally coupled maps, where the elements are
updated with probability . When is below a threshold , the
collective motion vanishes and the system is the stationary state in the large
size limit. We present the linear stability analysis.Comment: 6 pages including 5 figure
Monopoles, Dyons and Black Holes in the Four-Dimensional Einstein-Yang-Mills Theory
A continuum of monopole, dyon and black hole solutions exist in the
Einstein-Yang-Mills theory in asymptotically anti-de Sitter space. Their
structure is studied in detail. The solutions are classified by non-Abelian
electric and magnetic charges and the ADM mass. The stability of the solutions
which have no node in non-Abelian magnetic fields is established. There exist
critical spacetime solutions which terminate at a finite radius, and have
universal behavior. The moduli space of the solutions exhibits a fractal
structure as the cosmological constant approaches zero.Comment: 36 Pages, 16 Figures. Minor typos corrected and one figure modifie
Dyonic Non-Abelian Black Holes
We study static spherically symmetric dyonic black holes in
Einstein-Yang-Mills-Higgs theory. As for the magnetic non-abelian black holes,
the domain of existence of the dyonic non-abelian black holes is limited with
respect to the horizon radius and the dimensionless coupling constant ,
which is proportional to the ratio of vector meson mass and Planck mass. At a
certain critical value of this coupling constant, , the maximal
horizon radius is attained. We derive analytically a relation between and the charge of the black hole solutions and confirm this relation
numerically. Besides the fundamental dyonic non-abelian black holes, we study
radially excited dyonic non-abelian black holes and globally regular
gravitating dyons.Comment: LaTeX, 22 pages, 16 figures, three figures added, file manipulation
error in previous replac
On the susceptibility function of piecewise expanding interval maps
We study the susceptibility function Psi(z) associated to the perturbation
f_t=f+tX of a piecewise expanding interval map f. The analysis is based on a
spectral description of transfer operators. It gives in particular sufficient
conditions which guarantee that Psi(z) is holomorphic in a disc of larger than
one. Although Psi(1) is the formal derivative of the SRB measure of f_t with
respect to t, we present examples satisfying our conditions so that the SRB
measure is not Lipschitz.*We propose a new version of Ruelle's conjectures.* In
v2, we corrected a few minor mistakes and added Conjectures A-B and Remark 4.5.
In v3, we corrected the perturbation (X(f(x)) instead of X(x)), in particular
in the examples from Section 6. As a consequence, Psi(z) has a pole at z=1 for
these examples.Comment: To appear Comm. Math. Phy
- …