609 research outputs found
[Review of] Anne Wortham, The Other Side of Racism: A Philosophical Study of Black Race Consciousness
The author, a freelance writer, editor, and broadcast researcher .... (presently) a doctoral candidate in sociology at Boston College, proposes to study blacks who advocate black consciousness. Wortham condemns ethnic or racial consciousness, and therefore characterizes the other side of racism as a dilemma of individual self-esteem as opposed to problems of group conflict in race relations
[Review of] James A. Banks, Multiethnic Education: Theory and Practice
Aware of the philosophical disagreement and conceptualconfusion over the proper place of multiethnic education in the American school system, Banks has gone a long way in providing educators with a clear modus operandi in the field. The book is comprised of seventeen chapters divided into six parts; it also includes three useful appendices and an index
Analysis of the impact of IFRS standards on the accounting treatment of credit assets transfer and derecognition: A case study approach
Kinetic Equations for Baryogenesis via Sterile Neutrino Oscillation
We investigate baryogenesis in the MSM (neutrino Minimal Standard
Model), which is the MSM extended by three right-handed neutrinos with masses
below the electroweak scale. The baryon asymmetry of the universe can be
generated by the mechanism via flavor oscillation of right-handed (sterile)
neutrinos which are responsible to masses of active neutrinos confirmed by
various experiments. We present the kinetic equations for the matrix of
densities of leptons which describe the generation of asymmetries. Especially,
the momentum dependence of the matrix of densities is taken into account. By
solving these equations numerically, it is found that the momentum distribution
is significantly distorted from the equilibrium one, since the production for
the modes with lower momenta ( is the temperature of the universe)
is enhanced, while suppressed for higher modes. As a result, the most important
mode for the yields of sterile neutrinos as well as the baryon asymmetry is , which is smaller than inferred from the thermal average. The
comparison with the previous works is also discussed.Comment: 22 pages, 19 figure
Oxidizing SuperYang-Mills from (N=4,d=4) to (N=1,d=10)
We introduce superspace generalizations of the transverse derivatives to
rewrite the four-dimensional N=4 Yang-Mills theory into the fully
ten-dimensional N=1 Yang-Mills in light-cone form. The explicit SuperPoincare
algebra is constructed and invariance of the ten-dimensional action is proved.Comment: 15 page
A Completely Invariant SUSY Transform of Supersymmetric QED
We study the SUSY breaking of the covariant gauge-fixing term in SUSY QED and
observe that this corresponds to a breaking of the Lorentz gauge condition by
SUSY. Reasoning by analogy with SUSY's violation of the Wess-Zumino gauge, we
argue that the SUSY transformation, already modified to preserve Wess-Zumino
gauge, should be further modified by another gauge transformation which
restores the Lorentz gauge condition. We derive this modification and use the
resulting transformation to derive a Ward identitiy relating the photon and
photino propagators without using ghost fields. Our transformation also
fulfills the SUSY algebra, modulo terms that vanish in Lorentz gauge
The BLG Theory in Light-Cone Superspace
The light-cone superspace version of the d=3, N=8 superconformal theory of
Bagger, Lambert and Gustavsson (BLG) is obtained as a solution to constraints
imposed by OSp(2,2|8) superalgebra. The Hamiltonian of the theory is shown to
be a quadratic form of the dynamical supersymmetry transformation.Comment: 45 pages, v2: reference added, minor typos corrected, published
versio
Large Lepton Mixings from Continuous Symmetries
Within the broad context of quark-lepton unification, we investigate the
implications of broken continuous family symmetries which result from requiring
that in the limit of exact symmetry, the Dirac mass matrices yield hierarchical
masses for the quarks and charged leptons, but lead to degenerate light
neutrino masses as a consequence of the seesaw mechanism, without requiring
hierarchical right-handed neutrino mass terms. Quark mixing is then naturally
small and proportional to the size of the perturbation, but lepton mixing is
large as a result of degenerate perturbation theory, shifted from maximal
mixing by the size of the perturbation. Within this approach, we study an
illustrative two-family prototype model with an SO(2) family symmetry, and
discuss extensions to three-family models.Comment: 23 page
Path Integral for Inflationary Perturbations
The quantum theory of cosmological perturbations in single field inflation is
formulated in terms of a path integral. Starting from a canonical formulation,
we show how the free propagators can be obtained from the well known
gauge-invariant quadratic action for scalar and tensor perturbations, and
determine the interactions to arbitrary order. This approach does not require
the explicit solution of the energy and momentum constraints, a novel feature
which simplifies the determination of the interaction vertices. The constraints
and the necessary imposition of gauge conditions is reflected in the appearance
of various commuting and anti-commuting auxiliary fields in the action. These
auxiliary fields are not propagating physical degrees of freedom but need to be
included in internal lines and loops in a diagrammatic expansion. To illustrate
the formalism we discuss the tree-level 3-point and 4-point functions of the
inflaton perturbations, reproducing the results already obtained by the methods
used in the current literature. Loop calculations are left for future work.Comment: (v1) 28 pages, no figures; (v2) 29 pages, minor changes, matches
published versio
Continuous Spin Representations of the Poincar\'e and Super-Poincar\'e Groups
We construct Wigner's continuous spin representations of the Poincar\'e
algebra for massless particles in higher dimensions. The states are labeled
both by the length of a space-like translation vector and the Dynkin indices of
the {\it short little group} , where is the space-time dimension.
Continuous spin representations are in one-to-one correspondence with
representations of the short little group. We also demonstrate how combinations
of the bosonic and fermionic representations form supermultiplets of the
super-Poincar\'e algebra. If the light-cone translations are nilpotent, these
representations become finite dimensional, but contain zero or negative norm
states, and their supersymmetry algebra contains a central charge in four
dimensions.Comment: 19 page
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