2,495 research outputs found

    The Values Distribution in a Competing Shares Financial Market Model

    Full text link
    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 d(p,n)2pd(\vec{p},\vec{n})2p Reaction and Spin Response Functions of the Deuteron

    Full text link
    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 d(p,n)2pd(\vec{p},\vec{n})2p 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

    Full text link
    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

    Full text link
    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 2kF2k_F spin and 2kF2k_F charge fluctuations

    Full text link
    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 2kF2k_F spin and 2kF2k_F 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)2_2ClO4_4, 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

    Full text link
    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

    Full text link
    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 Sz=1S_z=1 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)2X_2X.Comment: 5 pages, 5 figures. To be published in Phys. Rev. Let

    Tensor Operators for Uh(sl(2))

    Full text link
    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.
    corecore