3,463 research outputs found
On statistical mechanics in noncommutative spaces
We study the formulation of quantum statistical mechanics in noncommutative
spaces. We construct microcanonical and canonical ensemble theory in
noncommutative spaces. We consider for illustration some basic and important
examples in the framework of noncommutative statistical mechanics : (i). An
electron in a magnetic field. (ii). A free particle in a box. (iii). A linear
harmonic oscillator.Comment: 9 pages, no figure
Scattering in Noncommutative Quantum Mechanics
We derive the correction due to noncommutativity of space on Born
approximation, then the correction for the case of Yukawa potential is
explicitly calculated. The correction depends on the angle of scattering. Using
partial wave method it is shown that the conservation of the number of
particles in elastic scattering is also valid in noncommutative spaces which
means that the unitarity relation is held in noncommutative spaces. We also
show that the noncommutativity of space has no effect on the optical theorem.
Finally we study Gaussian function potential in noncommutative spaces which
generates delta function potential as .Comment: 7 Pages, no figure, accepted for publication in Modern Physics
Letters
Large subgroups of simple groups
Let be a finite group. A proper subgroup of is said to be large
if the order of satisfies the bound . In this note we
determine all the large maximal subgroups of finite simple groups, and we
establish an analogous result for simple algebraic groups (in this context,
largeness is defined in terms of dimension). An application to triple
factorisations of simple groups (both finite and algebraic) is discussed.Comment: 37 page
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