4,990 research outputs found
Exponential Sums and Congruences with Factorials
We estimate the number of solutions of certain diagonal congruences involving
factorials. We use these results to bound exponential sums with products of two
factorials and also derive asymptotic formulas for the number of
solutions of various congruences with factorials. For example, we prove that
the products of two factorials with are
uniformly distributed modulo , and that any residue class modulo is
representable in the form with .Comment: 21 page
Character Sums and Congruences with n!
We estimate character sums with n!, on average, and individually. These
bounds are used to derive new results about various congruences modulo a prime
p and obtain new information about the spacings between quadratic nonresidues
modulo p. In particular, we show that there exists a positive integer \max \{n_i |
i=1,... 7\}=O(p^{11/12+\epsilon}), and we find the asymptotic formula for the
number of such representations. Finally, we show that products of 4 factorials
represent ``almost all''residue classes modulo p, and that products of 3
factorials n_1!n_2!n_3! with \max\{n_1, n_2, n_3\}=O(p^{5/6+\epsilon})$ are
uniformly distributed modulo p.Comment: 20 pages. Trans. Amer. Math. Soc. (to appear
Self-consistent variational approach to the minimal left-right symmetric model of electroweak interactions
The problem of mass generation is addressed by a Gaussian variational method
for the minimal left-right symmetric model of electroweak interactions. Without
any scalar bidoublet, the Gaussian effective potential is shown to have a
minimum for a broken symmetry vacuum with a finite expectation value for both
the scalar Higgs doublets. The symmetry is broken by the fermionic coupling
that destabilizes the symmetric vacuum, yielding a self consistent fermionic
mass. In this framework a light Higgs is only compatible with the existence of
a new high energy mass scale below 2 TeV.Comment: 5 pages, 3 figures. New comments added and typing errors in eq. 8 and
11 correcte
From the triangular to the kagome lattice: Following the footprints of the ordered state
We study the spin-1/2 Heisenberg model in a lattice that interpolates between
the triangular and the kagome lattices. The exchange interaction along the
bonds of the kagome lattice is J, and the one along the bonds connecting kagome
and non-kagome sites is J', so that J'=J corresponds to the triangular limit
and J'=0 to the kagome one. We use variational and exact diagonalization
techniques. We analyze the behavior of the order parameter for the
antiferromagnetic phase of the triangular lattice, the spin gap, and the
structure of the spin excitations as functions of J'/J. Our results indicate
that the antiferromagnetic order is not affected by the reduction of J' down to
J'/J ~ 0.2. Below this value, antiferromagnetic correlations grow weaker, a
description of the ground state in terms of a Neel phase renormalized by
quantum fluctuations becomes inadequate, and the finite-size spectra develop
features that are not compatible with antiferromagnetic ordering. However, this
phase does not appear to be connected to the kagome phase as well, as the
low-energy spectra do not evolve with continuity for J'-> 0 to the kagome
limit. In particular, for any non-zero value of J', the latter interaction sets
the energy scale for the low-lying spin excitations, and a gapless triplet
spectrum, destabilizing the kagome phase, is expected.Comment: 9 pages, 10 Figures. To be published in PR
Character sums and products of factorials modulo
In this paper, we apply character sum estimates to study products of factorials modulo p
Electronic phase separation near the superconductor-insulator transition of Nd1+xBa2âxCu3O7âÎŽ thin films studied by an electric-field-induced doping effect
We report a detailed study of the transport properties of Nd(1+x)Ba(2-x)Cu(3)O(7-delta) thin films with doping changed by field effect. The data cover the whole superconducting to insulating transition and show remarkable Similarities with the effect of chemical doping in high critical temperature superconductors. The results suggest that the add-on of carriers is accompanied by an electronic phase separation, independent on the details of the doping mechanism
Show me the product, show me the model: Effect of picture type on attitudes toward advertising
We suggest that a consideration of consumer selfĂą evaluations is fundamental to understanding the conditions under which it is more advantageous to present person or product pictures in print advertisements. We build on the basic human motives of selfĂą enhancement and selfĂą verification to propose that the specific selfĂą esteem level of consumers, in the domain relevant for the category, differentially affects their responses to picture type. Specifically, for consumers with low (high) domainĂą specific selfĂą esteem, depicting a product (person) in the advertisement enhances attitudes toward the advertisement more than depicting a person (product). In two studies, we demonstrate the proposed matching relationships using two different domains of consumer selfĂą evaluation: appearance selfĂą esteem and academic selfĂą esteem. We also show that increased and more fluent generation of selfĂą related mental imagery drives the observed improvement in attitudes toward the advertisement. Our findings suggest direct implications for advertising design.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141608/1/jcpy506.pd
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