57,190 research outputs found

    The Riemann hypothesis for certain integrals of Eisenstein series

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    This paper studies the non-holomorphic Eisenstein series E(z,s) for the modular surface, and shows that integration with respect to certain non-negative measures gives meromorphic functions of s that have all their zeros on the critical line Re(s) = 1/2. For the constant term of the Eisenstein series it shows that all zeros are on the critical line for fixed y= Im(z) \ge 1, except possibly for two real zeros, which are present if and only if y > 4 \pi e^{-\gamma} = 7.0555+. It shows the Riemann hypothesis holds for all truncation integrals with truncation parameter T \ge 1. For T=1 this proves the Riemann hypothesis for a zeta function recently introduced by Lin Weng, attached to rank 2 semistable lattices over the rationals.Comment: 23 pages; corrected residues of functions in theorem 1 and 2, added reference; v3 small corrections, removed uncited references; v4 more small correction

    Slow quench dynamics of the Kitaev model: anisotropic critical point and effect of disorder

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    We study the non-equilibrium slow dynamics for the Kitaev model both in the presence and the absence of disorder. For the case without disorder, we demonstrate, via an exact solution, that the model provides an example of a system with an anisotropic critical point and exhibits unusual scaling of defect density nn and residual energy QQ for a slow linear quench. We provide a general expression for the scaling of nn (QQ) generated during a slow power-law dynamics, characterized by a rate τ−1\tau^{-1} and exponent α\alpha, from a gapped phase to an anisotropic quantum critical point in dd dimensions, for which the energy gap Δk⃗∼kiz\Delta_{\vec k} \sim k_i^z for mm momentum components (i=1..mi=1..m) and ∼kiz′\sim k_i^{z'} for the rest d−md-m components (i=m+1..di=m+1..d) with z≤z′z\le z': n∼τ−[m+(d−m)z/z′]να/(zνα+1)n \sim \tau^{-[m + (d-m)z/z']\nu \alpha/(z\nu \alpha +1)} (Q∼τ−[(m+z)+(d−m)z/z′]να/(zνα+1)Q \sim \tau^{-[(m+z)+ (d-m)z/z']\nu \alpha/(z\nu \alpha +1)}). These general expressions reproduce both the corresponding results for the Kitaev model as a special case for d=z′=2d=z'=2 and m=z=ν=1m=z=\nu=1 and the well-known scaling laws of nn and QQ for isotropic critical points for z=z′z=z'. We also present an exact computation of all non-zero, independent, multispin correlation functions of the Kitaev model for such a quench and discuss their spatial dependence. For the disordered Kitaev model, where the disorder is introduced via random choice of the link variables DnD_n in the model's Fermionic representation, we find that n∼τ−1/2n \sim \tau^{-1/2} and Q∼τ−1Q\sim \tau^{-1} (Q∼τ−1/2Q\sim \tau^{-1/2}) for a slow linear quench ending in the gapless (gapped) phase. We provide a qualitative explanation of such scaling.Comment: 10 pages, 11 Figs. v

    Neutrino-12C scattering in the ab initio shell model with a realistic three-body interaction

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    We investigate cross sections for neutrino-12C exclusive scattering and for muon capture on 12C using wave functions obtained in the ab initio no-core shell model. In our parameter-free calculations with basis spaces up to the 6 hbarOmega we show that realistic nucleon-nucleon interactions, like e.g. the CD-Bonn, under predict the experimental cross sections by more than a factor of two. By including a realistic three-body interaction, Tucson-Melbourne TM'(99), the cross sections are enhanced significantly and a much better agreement with experiment is achieved. At the same time,the TM'(99) interaction improves the calculated level ordering in 12C. The comparison between the CD-Bonn and the three-body calculations provides strong confirmation for the need to include a realistic three-body interaction to account for the spin-orbit strength in p-shell nuclei.Comment: 6 pages, 2 figure

    Large basis ab initio shell model investigation of 9-Be and 11-Be

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    We are presenting the first ab initio structure investigation of the loosely bound 11-Be nucleus, together with a study of the lighter isotope 9-Be. The nuclear structure of these isotopes is particularly interesting due to the appearance of a parity-inverted ground state in 11-Be. Our study is performed in the framework of the ab initio no-core shell model. Results obtained using four different, high-precision two-nucleon interactions, in model spaces up to 9\hbar\Omega, are shown. For both nuclei, and all potentials, we reach convergence in the level ordering of positive- and negative-parity spectra separately. Concerning their relative position, the positive-parity states are always too high in excitation energy, but a fast drop with respect to the negative-parity spectrum is observed when the model space is increased. This behavior is most dramatic for 11-Be. In the largest model space we were able to reach, the 1/2+ level has dropped down to become either the first or the second excited state, depending on which interaction we use. We also observe a contrasting behavior in the convergence patterns for different two-nucleon potentials, and argue that a three-nucleon interaction is needed to explain the parity inversion. Furthermore, large-basis calculations of 13-C and 11-B are performed. This allows us to study the systematics of the position of the first unnatural-parity state in the N=7 isotone and the A=11 isobar. The 11-B run in the 9\hbar\Omega model space involves a matrix with dimension exceeding 1.1 x 10^9, and is our largest calculation so far. We present results on binding energies, excitation spectra, level configurations, radii, electromagnetic observables, and 10-Be+n overlap functions.Comment: 17 pages, 12 figures To be published in Phys. Rev. C Resubmitted version. Minor change
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