1,670 research outputs found

    Preservationism, or The Elephant in the Room: How Opponents of Same-Sex Marriage Deceive Us into Establishing Religion

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    The overwhelming majority of support for bans on same-sex civil marriage has come from religious believers, and the so-called secular justifications for these bans are mere pretexts for religious beliefs that homosexuality, homosexuals, and same-sex couples are evil or sinful. Courts should take a hard look at the substantive justifications offered in support of same-sex marriage bans, bearing in mind that (1) these justifications are universally offered by religious believers but are infrequently offered by credentialed Secularists, and (2) they are the result of a studied use of pretextual, secular-sounding language to cloak a religiously-motivated bias against homosexuals and same-sex couples

    Exact Five-Loop Renormalization Group Functions of ϕ4\phi^4-Theory with O(N)-Symmetric and Cubic Interactions. Critical Exponents up to \ep^5

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    The renormalization group functions are calculated in D=4−ϔD=4-\epsilon dimensions for the ϕ4\phi^4-theory with two coupling constants associated with an O(N){O}(N)-symmetric and a cubic interaction. Divergences are removed by minimal subtraction. The critical exponents η\eta, Îœ\nu, and ω\omega are expanded up to order Ï”5\epsilon^5 for the three nontrivial fixed points O(N)-symmetric, Ising, and cubic. The results suggest the stability of the cubic fixed point for N≄3N\geq3, implying that the critical exponents seen in the magnetic transition of three-dimensional cubic crystals are of the cubic universality class. This is in contrast to earlier three-loop results which gave N>3N > 3, and thus Heisenberg exponents. The numerical differences, however, are less than a percent making an experimental distinction of the universality classes very difficult.Comment: PostScript fil

    Ordered Phases of Itinerant Dzyaloshinsky-Moriya Magnets and Their Electronic Properties

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    A field theory appropriate for magnets that display helical order due to the Dzyaloshinsky-Moriya mechanism, a class that includes MnSi and FeGe, is used to derive the phase diagram in a mean-field approximation. The helical phase, the conical phase in an external magnetic field, and recent proposals for the structure of the A-phase and the non-Fermi-liquid region in the paramagnetic phase are discussed. It is shown that the orientation of the helical pitch vector along an external magnetic field within the conical phase occurs via two distinct phase transitions. The Goldstone modes that result from the long-range order in the various phases are determined, and their consequences for electronic properties, in particular the specific heat, the single-particle relaxation time, and the electrical and thermal conductivities, are derived. Various aspects of the ferromagnetic limit, and qualitative differences between the transport properties of helimagnets and ferromagnets, are also discussed.Comment: 22pp, 8 eps fig

    Connecting the Holographic and Wilsonian Renormalization Groups

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    Inspired by the AdS/CFT correspondence, we develop an explicit formal duality between the planar limit of a d-dimensional gauge theory and a classical field theory in a (d+1)-dimensional anti-de Sitter space. The key ingredient is the identification of fields in AdS with generalized Hubbard-Stratonovich transforms of single-trace couplings of the QFT. We show that the Wilsonian renormalization group flow of these transformed couplings matches the holographic (Hamilton-Jacobi) flow of bulk fields along the radial direction in AdS. This result allows one to outline an AdS/CFT dictionary that does not rely on string theory.Comment: 11 pages, 1 figure; metadata modified in v2; added references and minor changes in v3; v4 as published in JHE

    Renormalization Group Running of Newton's G: The Static Isotropic Case

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    Corrections are computed to the classical static isotropic solution of general relativity, arising from non-perturbative quantum gravity effects. A slow rise of the effective gravitational coupling with distance is shown to involve a genuinely non-perturbative scale, closely connected with the gravitational vacuum condensate, and thereby, it is argued, related to the observed effective cosmological constant. Several analogies between the proposed vacuum condensate picture of quantum gravitation, and non-perturbative aspects of vacuum condensation in strongly coupled non-abelian gauge theories are developed. In contrast to phenomenological approaches, the underlying functional integral formulation of the theory severely constrains possible scenarios for the renormalization group evolution of couplings. The expected running of Newton's constant GG is compared to known vacuum polarization induced effects in QED and QCD. The general analysis is then extended to a set of covariant non-local effective field equations, intended to incorporate the full scale dependence of GG, and examined in the case of the static isotropic metric. The existence of vacuum solutions to the effective field equations in general severely restricts the possible values of the scaling exponent Μ\nu.Comment: 61 pages, 3 figure

    On dimensional regularization of sums

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    We discuss a systematic way to dimensionally regularize divergent sums arising in field theories with an arbitrary number of physical compact dimensions or finite temperature. The method preserves the same symmetries of the action as the conventional dimensional regularization and allows an easy separation of the regulated divergence from the finite term that depends on the compactification radius (temperature).Comment: 22 pages, 1 figur

    Thermodynamics of a trapped interacting Bose gas and the renormalization group

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    We apply perturbative renormalization group theory to the symmetric phase of a dilute interacting Bose gas which is trapped in a three-dimensional harmonic potential. Using Wilsonian energy-shell renormalization and the epsilon-expansion, we derive the flow equations for the system. We relate these equations to the flow for the homogeneous Bose gas. In the thermodynamic limit, we apply our results to study the transition temperature as a function of the scattering length. Our results compare well to previous studies of the problem.Comment: 14 pages, 5 figure

    Non-Perturbative Gravity and the Spin of the Lattice Graviton

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    The lattice formulation of quantum gravity provides a natural framework in which non-perturbative properties of the ground state can be studied in detail. In this paper we investigate how the lattice results relate to the continuum semiclassical expansion about smooth manifolds. As an example we give an explicit form for the lattice ground state wave functional for semiclassical geometries. We then do a detailed comparison between the more recent predictions from the lattice regularized theory, and results obtained in the continuum for the non-trivial ultraviolet fixed point of quantum gravity found using weak field and non-perturbative methods. In particular we focus on the derivative of the beta function at the fixed point and the related universal critical exponent Μ\nu for gravitation. Based on recently available lattice and continuum results we assess the evidence for the presence of a massless spin two particle in the continuum limit of the strongly coupled lattice theory. Finally we compare the lattice prediction for the vacuum-polarization induced weak scale dependence of the gravitational coupling with recent calculations in the continuum, finding similar effects.Comment: 46 pages, one figur

    On the Convergence of the Expansion of Renormalization Group Flow Equation

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    We compare and discuss the dependence of a polynomial truncation of the effective potential used to solve exact renormalization group flow equation for a model with fermionic interaction (linear sigma model) with a grid solution. The sensitivity of the results on the underlying cutoff function is discussed. We explore the validity of the expansion method for second and first-order phase transitions.Comment: 12 pages with 10 EPS figures included; revised versio
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