762 research outputs found
Automorphic equivalence of the representations of Lie algebras
We prove that if a field k is infinite, char(k)=0 and k has not nontrivial
automorphisms then automorphic equivalence of representations of Lie algebras
coincide with geometric equivalence. We achieve our result by consideration of
1-sorted objects. We suppose that our method can be perspective in the further
researches.Comment: 28 page
Associative nil-algebras over finite fields
The nilpotency degree of a relatively free finitely generated associative
algebra with the identity is studied over finite fields.Comment: 12 page
Indexing of the space data in the CSDB Microsoft SQL Server 2000
2 schemes of space indexing are realized in environment of CSDB Microsoft SQL Server 2000. The experimental research of the realized methods for window inquiries is carried out. Comparison of the realized methods with available in the standard means of indexing being in the given CSDB has been carried out. To find the quadrant splitting in methods Z-and XZ-indexing the heuristic algorithm which gives a smaller error of approximation in comparison with standard algorithm is proposed
Impurity-induced smearing of the spin resonance peak in Fe-based superconductors
The spin resonance peak in the iron-based superconductors is observed in
inelastic neutron scattering experiments and agrees well with predicted results
for the extended s-wave () gap symmetry. On the basis of four-band and
three-orbital tight binding models we study the effect of nonmagnetic disorder
on the resonance peak. Spin susceptibility is calculated in the random phase
approximation with the renormalization of the quasiparticle self-energy due to
the impurity scattering in the static Born approximation. We find that the spin
resonance becomes broader with the increase of disorder and its energy shifts
to higher frequencies. For the same amount of disorder the spin response in the
state is still distinct from that of the state.Comment: 4 pages, 2 figure
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