565 research outputs found
Wheeled PROPs, graph complexes and the master equation
We introduce and study wheeled PROPs, an extension of the theory of PROPs
which can treat traces and, in particular, solutions to the master equations
which involve divergence operators. We construct a dg free wheeled PROP whose
representations are in one-to-one correspondence with formal germs of
SP-manifolds, key geometric objects in the theory of Batalin-Vilkovisky
quantization. We also construct minimal wheeled resolutions of classical
operads Com and Ass as rather non-obvious extensions of Com_infty and
Ass_infty, involving, e.g., a mysterious mixture of associahedra with
cyclohedra. Finally, we apply the above results to a computation of cohomology
of a directed version of Kontsevich's complex of ribbon graphs.Comment: LaTeX2e, 63 pages; Theorem 4.2.5 on bar-cobar construction is
strengthene
Frobenius manifold structures on the spaces of abelian integrals
Frobenius manifold structures on the spaces of abelian integrals were
constructed by I. Krichever. We use D-modules, deformation theory, and
homological algebra to give a coordinate-free description of these structures.
It turns out that the tangent sheaf multiplication has a cohomological origin,
while the Levi-Civita connection is related to 1-dimensional isomonodromic
deformations.Comment: Expanded version. The case of an abelian integral with multiple poles
is treated. Other minor improvements. Final versio
Weak localization of holes in high-mobility heterostructures
Theory of weak localization is developed for two-dimensional holes in
semiconductor heterostructures. Ballistic regime of weak localization where the
backscattering occurs from few impurities is studied with account for
anisotropic momentum scattering of holes. The transition from weak localization
to anti-localization is demonstrated for long dephasing times. For stronger
dephasing the conductivity correction is negative at all hole densities due to
non-monotonous dependence of the spin relaxation time on the hole wavevector.
The anomalous temperature dependent correction to the conductivity is
calculated. We show that the temperature dependence of the conductivity is
non-monotonous at moderate hole densities.Comment: 5 pages, 4 figure
Interval total colorings of graphs
A total coloring of a graph is a coloring of its vertices and edges such
that no adjacent vertices, edges, and no incident vertices and edges obtain the
same color. An \emph{interval total -coloring} of a graph is a total
coloring of with colors such that at least one vertex or edge
of is colored by , , and the edges incident to each vertex
together with are colored by consecutive colors, where
is the degree of the vertex in . In this paper we investigate
some properties of interval total colorings. We also determine exact values of
the least and the greatest possible number of colors in such colorings for some
classes of graphs.Comment: 23 pages, 1 figur
Inducing Barbero-Immirzi Connections along SU(2)-reductions of Bundles on Spacetime
We shall present here a general apt technique to induce connections along
bundle reductions which is different from the standard restriction. This
clarifies and generalizes the standard procedure to define Barbero-Immirzi (BI)
connection, though on spacetime. The standard spacial BI connection used in LQG
is then obtained by its spacetime version by standard restriction. The general
prescription to define such a reduced connection is interesting from a
mathematical viewpoint and it allows a general and direct control on
transformation laws of the induced object. Moreover, unlike what happens by
using standard restriction, we shall show that once a bundle reduction is
given, then any connection induces a reduced connection with no constraint on
the original holonomy as it happens when connections are simply restricted.Comment: 6 pages, some comments adde
Coordination Methods and Forms
The problem of behavior, action-reaction coordination remains its actuality for regulation and managing by social subjects. The decision by different methodology approaches in sciences and practice seeks its true efficiency proofing. Efficiency providing needs by management tasks technology rationality. Classifying measures became a ground coordination problem solution
Classification and Volume Coordination Tasks of Organization Activity and Behavior
Based on the process approach, the article classifes the types of coordination tasks of different complexity and forms. Factors of influence on labor intensity of coordination tasks of activities and behavior are identifed. It is proposed to group factors of influence on the standard of manageability in connection with the solution of coordination tasks. The need and composition of the tasks of using informal relations and structure in coordination are justifed
Long-term Dynamics of the Electron-nuclear Spin System of a Semiconductor Quantum Dot
A quasi-classical theoretical description of polarization and relaxation of
nuclear spins in a quantum dot with one resident electron is developed for
arbitrary mechanisms of electron spin polarization. The dependence of the
electron-nuclear spin dynamics on the correlation time of electron
spin precession, with frequency , in the nuclear hyperfine field is
analyzed. It is demonstrated that the highest nuclear polarization is achieved
for a correlation time close to the period of electron spin precession in the
nuclear field. For these and larger correlation times, the indirect hyperfine
field, which acts on nuclear spins, also reaches a maximum. This maximum is of
the order of the dipole-dipole magnetic field that nuclei create on each other.
This value is non-zero even if the average electron polarization vanishes. It
is shown that the transition from short correlation time to
does not affect the general structure of the equation for nuclear spin
temperature and nuclear polarization in the Knight field, but changes the
values of parameters, which now become functions of . For
correlation times larger than the precession time of nuclei in the electron
hyperfine field, it is found that three thermodynamic potentials (,
, ) characterize the polarized electron-nuclear spin
system. The values of these potentials are calculated assuming a sharp
transition from short to long correlation times, and the relaxation mechanisms
of these potentials are discussed. The relaxation of the nuclear spin potential
is simulated numerically showing that high nuclear polarization decreases
relaxation rate.Comment: RevTeX 4, 12 pages, 9 figure
Structural adaptation of Salsola soda L. (Chenopodiaceae) from inland and maritime saline area
The microscopic analysis of leaf and stem in two populations of Salsola soda
was carried out in order to examine mechanism of anatomical adaptations to
environmental condition on saline habitats and to determine if there exists a
morpho-anatomical differentiation between populations from maritime and
inland saline area. Analysis included 26 quantitative characters of leaf and
stem. The results showed that both populations exhibited halomorphic and
xeromorphic adaptations, which refered to ecological plasticity and
adaptations of plants to their habitats. Our research also showed that S.
soda had quite a stable morphoanatomical structure, since only quantitative
changes were recorded. [Projekat Ministarstva nauke Republike Srbije, br.
173002
One-dimensional Chern-Simons theory
We study a one-dimensional toy version of the Chern-Simons theory. We
construct its simplicial version which comprises features of a low-energy
effective gauge theory and of a topological quantum field theory in the sense
of Atiyah.Comment: 37 page
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