9,620 research outputs found
Learning and Communication in Sender-Receiver Games: An Econometric Investigation
Learning and communication play important roles in coordinating activities. Game theory and experiments have made a significant contribution to our understanding and appreciation for the issues surrounding learning and communication in coordination. However, the results of past experimental studies provide conflicting results about the performance of learning models. Moreover, the interaction between learning and communication has not been systematically investigated. Our long run objective is to overcome the conflicting results and to provide a better understanding of the interaction. To this end, we econometrically investigate a sender-receiver game environment where communication is necessary for coordination and learning is essential for communication.
System-adapted correlation energy density functionals from effective pair interactions
We present and discuss some ideas concerning an ``average-pair-density
functional theory'', in which the ground-state energy of a many-electron system
is rewritten as a functional of the spherically and system-averaged pair
density. These ideas are further clarified with simple physical examples. We
then show that the proposed formalism can be combined with density functional
theory to build system-adapted correlation energy functionals. A simple
approximation for the unknown effective electron-electron interaction that
enters in this combined approach is described, and results for the He series
and for the uniform electron gas are briefly reviewed.Comment: to appear in Phil. Mag. as part of Conference proceedings for the
"Electron Correlations and Materials Properties", Kos Greece, July 5-9, 200
On the homotopy classification of elliptic operators on stratified manifolds
We find the stable homotopy classification of elliptic operators on
stratified manifolds. Namely, we establish an isomorphism of the set of
elliptic operators modulo stable homotopy and the -homology group of the
singular manifold. As a corollary, we obtain an explicit formula for the
obstruction of Atiyah--Bott type to making interior elliptic operators
Fredholm.Comment: 28 pages; submitted to Izvestiya Ross. Akad. Nau
Heat Conduction in One-Dimensional chain of Hard Discs with Substrate Potential
Heat conduction of one-dimensional chain of equivalent rigid particles in the
field of external on-site potential is considered. Zero diameters of the
particles correspond to exactly integrable case with divergent heat conduction
coefficient. By means of simple analytical model it is demonstrated that for
any nonzero particle size the integrability is violated and the heat conduction
coefficient converges. The result of the analytical computation is verified by
means of numerical simulation in a plausible diapason of parameters and good
agreement is observedComment: 14 pages, 7 figure
Symmetry breaking in the self-consistent Kohn-Sham equations
The Kohn-Sham (KS) equations determine, in a self-consistent way, the
particle density of an interacting fermion system at thermal equilibrium. We
consider a situation when the KS equations are known to have a unique solution
at high temperatures and this solution is a uniform particle density. We show
that, at zero temperature, there are stable solutions that are not uniform. We
provide the general principles behind this phenomenon, namely the conditions
when it can be observed and how to construct these non-uniform solutions. Two
concrete examples are provided, including fermions on the sphere which are
shown to crystallize in a structure that resembles the C molecule.Comment: a few typos eliminate
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