468 research outputs found

    A Reprise of Warrants, Probable Cause, and Articulable Suspicion in Immigration Enforcement—LaDuke v. Nelson, 762 F.2d 1318 (9th Cir. 1985)

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    This Note analyzes LaDuke v. Nelson, in which the Ninth Circuit held that the farm and ranch check practices of the INS violated the fourth amendment in that seizures were made without warrants, probable cause, or articulable suspicion of illegal alienage. The court\u27s alternative holding criticized the INS for conducting searches without warrants, probable cause, or effective consent. For LaDuke to stand it must be carefully distinguished from the Supreme Court\u27s most recent fourth amendment decisions, which juxtapose the individual\u27s interest in privacy and security with the government\u27s interest in effective law enforcement. LaDuke should stand because it provides an appropriate standard for cases which involve searches and seizures for the purpose of apprehending farm workers who are illegal aliens. That standard prevents the INS from harassing citizens and lawfully present aliens based on their racial or ethnic characteristics. It also prohibits the INS from harassing citizens and legal aliens based on their presumed proximity to illegal aliens

    Representations of integers by certain positive definite binary quadratic forms

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    We prove part of a conjecture of Borwein and Choi concerning an estimate on the square of the number of solutions to n=x^2+Ny^2 for a squarefree integer N.Comment: 8 pages, submitte

    Random matrix theory, the exceptional Lie groups, and L-functions

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    There has recently been interest in relating properties of matrices drawn at random from the classical compact groups to statistical characteristics of number-theoretical L-functions. One example is the relationship conjectured to hold between the value distributions of the characteristic polynomials of such matrices and value distributions within families of L-functions. These connections are here extended to non-classical groups. We focus on an explicit example: the exceptional Lie group G_2. The value distributions for characteristic polynomials associated with the 7- and 14-dimensional representations of G_2, defined with respect to the uniform invariant (Haar) measure, are calculated using two of the Macdonald constant term identities. A one parameter family of L-functions over a finite field is described whose value distribution in the limit as the size of the finite field grows is related to that of the characteristic polynomials associated with the 7-dimensional representation of G_2. The random matrix calculations extend to all exceptional Lie groupsComment: 14 page

    The nonrelativistic limit of the Magueijo-Smolin model of deformed special relativity

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    We study the nonrelativistic limit of the motion of a classical particle in a model of deformed special relativity and of the corresponding generalized Klein-Gordon and Dirac equations, and show that they reproduce nonrelativistic classical and quantum mechanics, respectively, although the rest mass of a particle no longer coincides with its inertial mass. This fact clarifies the meaning of the different definitions of velocity of a particle available in DSR literature. Moreover, the rest mass of particles and antiparticles differ, breaking the CPT invariance. This effect is close to observational limits and future experiments may give indications on its effective existence.Comment: 10 pages, plain TeX. Discussion of generalized Dirac equation and CPT violation adde

    Advection of vector fields by chaotic flows

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    We have introduced a new transfer operator for chaotic flows whose leading eigenvalue yields the dynamo rate of the fast kinematic dynamo and applied cycle expansion of the Fredholm determinant of the new operator to evaluation of its spectrum. The theory hs been tested on a normal form model of the vector advecting dynamical flow. If the model is a simple map with constant time between two iterations, the dynamo rate is the same as the escape rate of scalar quantties. However, a spread in Poincar\'e section return times lifts the degeneracy of the vector and scalar advection rates, and leads to dynamo rates that dominate over the scalar advection rates. For sufficiently large time spreads we have even found repellers for which the magnetic field grows exponentially, even though the scalar densities are decaying exponentially.Comment: 12 pages, Latex. Ask for figures from [email protected]

    Some recursive formulas for Selberg-type integrals

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    A set of recursive relations satisfied by Selberg-type integrals involving monomial symmetric polynomials are derived, generalizing previously known results. These formulas provide a well-defined algorithm for computing Selberg-Schur integrals whenever the Kostka numbers relating Schur functions and the corresponding monomial polynomials are explicitly known. We illustrate the usefulness of our results discussing some interesting examples.Comment: 11 pages. To appear in Jour. Phys.

    The trace of the heat kernel on a compact hyperbolic 3-orbifold

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    The heat coefficients related to the Laplace-Beltrami operator defined on the hyperbolic compact manifold H^3/\Ga are evaluated in the case in which the discrete group \Ga contains elliptic and hyperbolic elements. It is shown that while hyperbolic elements give only exponentially vanishing corrections to the trace of the heat kernel, elliptic elements modify all coefficients of the asymptotic expansion, but the Weyl term, which remains unchanged. Some physical consequences are briefly discussed in the examples.Comment: 11 page

    Wigner quantization of some one-dimensional Hamiltonians

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    Recently, several papers have been dedicated to the Wigner quantization of different Hamiltonians. In these examples, many interesting mathematical and physical properties have been shown. Among those we have the ubiquitous relation with Lie superalgebras and their representations. In this paper, we study two one-dimensional Hamiltonians for which the Wigner quantization is related with the orthosymplectic Lie superalgebra osp(1|2). One of them, the Hamiltonian H = xp, is popular due to its connection with the Riemann zeros, discovered by Berry and Keating on the one hand and Connes on the other. The Hamiltonian of the free particle, H_f = p^2/2, is the second Hamiltonian we will examine. Wigner quantization introduces an extra representation parameter for both of these Hamiltonians. Canonical quantization is recovered by restricting to a specific representation of the Lie superalgebra osp(1|2)

    A random matrix decimation procedure relating β=2/(r+1)\beta = 2/(r+1) to β=2(r+1)\beta = 2(r+1)

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    Classical random matrix ensembles with orthogonal symmetry have the property that the joint distribution of every second eigenvalue is equal to that of a classical random matrix ensemble with symplectic symmetry. These results are shown to be the case r=1r=1 of a family of inter-relations between eigenvalue probability density functions for generalizations of the classical random matrix ensembles referred to as β\beta-ensembles. The inter-relations give that the joint distribution of every (r+1)(r+1)-st eigenvalue in certain β\beta-ensembles with β=2/(r+1)\beta = 2/(r+1) is equal to that of another β\beta-ensemble with β=2(r+1)\beta = 2(r+1). The proof requires generalizing a conditional probability density function due to Dixon and Anderson.Comment: 19 pages, 1 figur
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