42 research outputs found
Relativistic diffusive motion in random electromagnetic fields
We show that the relativistic dynamics in a Gaussian random electromagnetic
field can be approximated by the relativistic diffusion of Schay and Dudley.
Lorentz invariant dynamics in the proper time leads to the diffusion in the
proper time. The dynamics in the laboratory time gives the diffusive transport
equation corresponding to the Juettner equilibrium at the inverse temperature
\beta^{-1}=mc^{2}. The diffusion constant is expressed by the field strength
correlation function (Kubo's formula).Comment: the version published in JP
Supersymmetric Noether Currents and Seiberg-Witten Theory
The purpose of this paper is twofold. The first purpose is to review a
systematic construction of Noether currents for supersymmetric theories,
especially effective supersymmetric theories. The second purpose is to use
these currents to derive the mass-formula for the quantized Seiberg-Witten
model from the supersymmetric algebra. We check that the mass-formula of the
low-energy theory agrees with that of the full theory (in the broken phase).Comment: 30 pages, LaTe
An axially symmetric solution of metric-affine gravity
We present an exact stationary {\it axially symmetric} vacuum solution of
metric-affine gravity (MAG) which generalises the recently reported spherically
symmetric solution. Besides the metric, it carries nonmetricity and torsion as
post-Riemannian geometrical structures. The parameters of the solution are
interpreted as mass and angular momentum and as dilation, shear and spin
charges.Comment: 5 pages, RevTe
Spontaneous Breaking of N=2 to N=1 in Rigid and Local Supersymmetric Theories
We analyze the relation between rigid and local supersymmetric N=2 field
theories, when half of the supersymmetries are spontaneously broken. In
particular, we show that the recently found partial supersymmety breaking
induced by electric and magnetic Fayet-Iliopoulos terms in rigid theories can
be obtained by a suitable flat limit of previously constructed N=2 supergravity
models with partial super-Higgs in the observable sector.Comment: 9 pages, plain Late
N=2 supersymmetry breaking at two different scales
We study N=2 spontaneous supersymmetry breaking at two different scales with
matter fields in hypermultiplets charged under the gauge group that should
involve at least two U(1) factors. Off-shell analysis is possible in the dual
single-tensor formulation of the hypermultiplets. Massless fermions can
naturally arise from pseudo-real representations of the gauge group that allow
a reformulation of the problem of chirality in N=2 theories. The above
properties are necessary ingredients towards constructing viable extensions of
the Standard Model based on N=2 supersymmetry.Comment: 26 page
Relativistic diffusion of elementary particles with spin
We obtain a generalization of the relativistic diffusion of Schay and Dudley
for particles with spin. The diffusion equation is a classical version of an
equation for the Wigner function of an elementary particle. The elementary
particle is described by a unitary irreducible representation of the Poincare
group realized in the Hilbert space of wave functions in the momentum space.
The arbitrariness of the Wigner rotation appears as a gauge freedom of the
diffusion equation. The spin is described as a connection of a fiber bundle
over the momentum hyperbolic space (the mass-shell). Motion in an
electromagnetic field, transport equations and equilibrium states are
discussed.Comment: 21 pages,minor changes,the version published in Journ.Phys.
Partial Breaking of N=2 Supersymmetry and of Gauge Symmetry in the U(N) Gauge Model
We explore vacua of the U(N) gauge model with N=2 supersymmetry recently
constructed in hep-th/0409060. In addition to the vacuum previously found with
unbroken U(N) gauge symmetry in which N=2 supersymmetry is partially broken to
N=1, we find cases in which the gauge symmetry is broken to a product gauge
group \prod_{i=1}^n U(N_i). The N=1 vacua are selected by the requirement of a
positive definite Kahler metric. We obtain the masses of the supermultiplets
appearing on the N=1 vacua.Comment: 23 pages, 3 figures; references added and typos correcte
Black Hole Entropy in Induced Gravity: Reduction to 2D Quantum Field Theory on the Horizon
It is argued that degrees of freedom responsible for the Bekenstein-Hawking
entropy of a black hole in induced gravity are described by two dimensional
quantum field theory defined on the bifurcation surface of the horizon. This
result is proved for a class of induced gravity models with scalar, spinor and
vector heavy constituents.Comment: 19 pages, latex, no figure