29,928 research outputs found
Symmetry transformations in Batalin-Vilkovisky formalism
This short note is closely related to Sen-Zwiebach paper on gauge
transformations in Batalin-Vilkovisky theory (hep-th 9309027). We formulate
some conditions of physical equivalence of solutions to the quantum master
equation and use these conditions to give a very transparent analysis of
symmetry transformations in BV-approach. We prove that in some sense every
quantum observable (i.e. every even function obeying
) determines a symmetry of the theory with the action
functional satisfying quantum master equation \endComment: 3 page
Homology of Lie algebra of supersymmetries and of super Poincare Lie algebra
We study the homology and cohomology groups of super Lie algebra of
supersymmetries and of super Poincare Lie algebra in various dimensions. We
give complete answers for (non-extended) supersymmetry in all dimensions . For dimensions we describe also the cohomology of reduction of
supersymmetry Lie algebra to lower dimensions. Our methods can be applied to
extended supersymmetry algebra.Comment: New version with some additions and correction
1RXSJ062518.2+733433: A bright, soft intermediate polar
We present the results of 50 hours time-resolved R-band photometry of the
ROSAT all-sky survey source 1RXSJ062518.2+733433. The source was identified by
Wei et al. (1999) as a cataclysmic variable. Our photometry, performed in 10
nights between February 11, 2003, and March 21, 2003, reveals two stable
periodicities at 19.7874 and 283.118 min, which are identified as probable spin
and orbital periods of the binary. We therefore classify 1RXSJ062518.2+733433
as an intermediate polar. Analysis of the RASS X-ray observations reveal a
variability of 100% in the X-ray flux and a likely soft X-ray excess. The new
IP thus joins the rare group of soft IPs with only four members so far.Comment: submitted to A&A, 5 pages, 6 figures of reduced qualit
Abelian Duality
We show that on three-dimensional Riemannian manifolds without boundaries and
with trivial first real de Rham cohomology group (and in no other dimensions)
scalar field theory and Maxwell theory are equivalent: the ratio of the
partition functions is given by the Ray-Singer torsion of the manifold. On the
level of interaction with external currents, the equivalence persists provided
there is a fixed relation between the charges and the currents.Comment: 11 pages, LaTeX, no figures, a reference added, submitted to Phys.
Rev.
Buckling without bending: a new paradigm in morphogenesis
A curious feature of organ and organoid morphogenesis is that in certain
cases, spatial oscillations in the thickness of the growing "film" are
out-of-phase with the deformation of the slower-growing "substrate," while in
other cases, the oscillations are in-phase. The former cannot be explained by
elastic bilayer instability, and contradict the notion that there is a
universal mechanism by which brains, intestines, teeth, and other organs
develop surface wrinkles and folds. Inspired by the microstructure of the
embryonic cerebellum, we develop a new model of 2d morphogenesis in which
system-spanning elastic fibers endow the organ with a preferred radius, while a
separate fiber network resides in the otherwise fluid-like film at the outer
edge of the organ and resists thickness gradients thereof. The tendency of the
film to uniformly thicken or thin is described via a "growth potential".
Several features of cerebellum, +blebbistatin organoid, and retinal fovea
morphogenesis, including out-of-phase behavior and a film thickness amplitude
that is comparable to the radius amplitude, are readily explained by our simple
analytical model, as may be an observed scale-invariance in the number of folds
in the cerebellum. We also study a nonlinear variant of the model, propose
further biological and bio-inspired applications, and address how our model is
and is not unique to the developing nervous system.Comment: version accepted by Physical Review
M-Theory on (K3 X S^1)/Z_2
We analyze -theory compactified on where the
changes the sign of the three form gauge field, acts on as a parity
transformation and on K3 as an involution with eight fixed points preserving
SU(2) holonomy. At a generic point in the moduli space the resulting theory has
as its low energy limit N=1 supergravity theory in six dimensions with eight
vector, nine tensor and twenty hypermultiplets. The gauge symmetry can be
enhanced (e.g. to ) at special points in the moduli space. At other
special points in the moduli space tensionless strings appear in the theory.Comment: LaTeX file, 11 page
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