1,677 research outputs found
Preservationism, or The Elephant in the Room: How Opponents of Same-Sex Marriage Deceive Us into Establishing Religion
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 -Theory with O(N)-Symmetric and Cubic Interactions. Critical Exponents up to \ep^5
The renormalization group functions are calculated in
dimensions for the -theory with two coupling constants associated with
an -symmetric and a cubic interaction. Divergences are removed by
minimal subtraction. The critical exponents , , and are
expanded up to order for the three nontrivial fixed points
O(N)-symmetric, Ising, and cubic. The results suggest the stability of the
cubic fixed point for , 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 , 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
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
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
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 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 , 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 .Comment: 61 pages, 3 figure
On dimensional regularization of sums
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
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
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 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
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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