2,495 research outputs found
The Values Distribution in a Competing Shares Financial Market Model
We present our competing shares financial market model and describe its
behaviour by numerical simulation. We show that in the critical region the
distribution avalanches of the market value as defined in this model has a
power-law distribution with exponent around 2.3. In this region the price
returns distribution is truncated Levy stable with exponent near the observed
value.Comment: 7 pages ps file with 6 eps figures. Latex source file. To appear in
Proceedings of Third Tohwa University Conference on Statistical Physics,
Japan, Nov.199
Quasi-Elastic Reaction and Spin Response Functions of the Deuteron
We calculated response functions of the deuteron for charge exchange
processes, including the final state interaction between two protons. Using
them we evaluated the double differential cross section and polarization
observables of by means of plane wave impulse
approximation with an optimal factorization. Calculation well reproduced the
shape of the energy spectra of the cross section, though somewhat overestimated
the magnitude. It also reproduced the spin observables well.Comment: 19 pages of LaTeX (4 figures not included, hard copy available upon
request), UT-Komaba 93-2
Lowest weight representations of super Schrodinger algebras in low dimensional spacetime
We investigate the lowest weight representations of the super Schrodinger
algebras introduced by Duval and Horvathy. This is done by the same procedure
as the semisimple Lie algebras. Namely, all singular vectors within the Verma
modules are constructed explicitly then irreducibility of the associated
quotient modules is studied again by the use of singular vectors. We present
the classification of irreducible Verma modules for the super Schrodinger
algebras in (1+1) and (2+1) dimensional spacetime with N = 1, 2 extensions.Comment: 10pages, talk given at GROUP28 conference New Castle 26-30th July
2010, reference adde
Combining Text and Formula Queries in Math Information Retrieval: Evaluation of Query Results Merging Strategies
Specific to Math Information Retrieval is combining text with mathematical
formulae both in documents and in queries. Rigorous evaluation of query
expansion and merging strategies combining math and standard textual keyword
terms in a query are given. It is shown that techniques similar to those known
from textual query processing may be applied in math information retrieval as
well, and lead to a cutting edge performance. Striping and merging partial
results from subqueries is one technique that improves results measured by
information retrieval evaluation metrics like Bpref
Strong magnetic field enhancement of spin triplet pairing arising from coexisting spin and charge fluctuations
We study the effect of the magnetic field (Zeeman splitting) on the triplet
pairing. We show generally that the enhancement of spin triplet pairing
mediated by coexisting spin and charge fluctuations can be much
larger than in the case of triplet pairing mediated by ferromagnetic spin
fluctuations. We propose that this may be related to the recent experiment for
(TMTSF)ClO, in which a possibility of singlet to triplet pairing
transition has been suggested.Comment: 5 page
Tunneling splitting of magnetic levels in Fe8 detected by 1H NMR cross relaxation
Measurements of proton NMR and the spin lattice relaxation rate 1/T1 in the
octanuclear iron (III) cluster [Fe8(N3C6H15)6O2(OH)12][Br8 9H2O], in short Fe8,
have been performed at 1.5 K in a powder sample aligned along the main
anisotropy z axis, as a function of a transverse magnetic field (i.e.,
perpendicular to the main easy axis z). A big enhancement of 1/T1 is observed
over a wide range of fields (2.5-5 T), which can be attributed to the tunneling
dynamics; in fact, when the tunneling splitting of the pairwise degenerate
m=+-10 states of the Fe8 molecule becomes equal to the proton Larmor frequency
a very effective spin lattice relaxation channel for the nuclei is opened. The
experimental results are explained satisfactorily by considering the
distribution of tunneling splitting resulting from the distribution of the
angles in the hard xy plane for the aligned powder, and the results of the
direct diagonalization of the model Hamiltonian.Comment: J. Appl. Phys., in pres
Strong parity mixing in the FFLO superconductivity in systems with coexisting spin and charge fluctuations
We study the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state of spin
fluctuation mediated pairing, and focus on the effect of coexisting charge
fluctuations. We find that (i) consecutive transitions from singlet pairing to
FFLO and further to triplet pairing can generally take place upon
increasing the magnetic field when strong charge fluctuations coexist with spin
fluctuations, and (ii) the enhancement of the charge fluctuations lead to a
significant increase of the parity mixing in the FFLO state, where the
triplet/singlet component ratio in the gap function can be close to unity.
We propose that such consecutive pairing state transition and strong parity
mixing in the FFLO state may take place in a quasi-one-dimensional organic
superconductor (TMTSF).Comment: 5 pages, 5 figures. To be published in Phys. Rev. Let
Tensor Operators for Uh(sl(2))
Tensor operators for the Jordanian quantum algebra Uh(sl(2)) are considered.
Some explicit examples of them, which are obtained in the boson or fermion
realization, are given and their properties are studied. It is also shown that
the Wigner-Eckart's theorem can be extended to Uh(sl(2)).Comment: 11pages, LaTeX, to be published in J. Phys.
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