27,836 research outputs found
CCD Photometry of Delta Scuti stars 7 Aql and 8 Aql
As a continuation of the study of the Delta Scuti stars 7 Aql and 8 Aql; new
CCD photometric data were acquired in 2007. We present a period analysis on
these data that confirm the dominant modes detected in each star in the
framework of the STEPHI XII campaign in 2003.Comment: 9 pages, 7 figures, 2 tables; Accepted for publication in
Communications in Asteroseismology, Vol 153, 200
Exact Chiral Symmetry on the Lattice
Developments during the last eight years have refuted the folklore that
chiral symmetries cannot be preserved on the lattice. The mechanism that
permits chiral symmetry to coexist with the lattice is quite general and may
work in Nature as well. The reconciliation between chiral symmetry and the
lattice is likely to revolutionize the field of numerical QCD.Comment: 30 pages, LaTeX, reference adde
Gravitational Lorentz anomaly from the overlap formula in 2-dimensions
In this letter we show that the overlap formulation of chiral gauge theories
correctly reproduces the gravitational Lorentz anomaly in 2-dimensions. This
formulation has been recently suggested as a solution to the fermion doubling
problem on the lattice. The well known response to general coordinate
transformations of the effective action of Weyl fermions coupled to gravity in
2-dimensions can also be recovered.Comment: 7 pages, late
Membrane solitons in eight-dimensional hyper-Kaehler backgrounds
We derive the BPS equations satisfied by lump solitons in -dimensional
sigma models with toric 8-dimensional hyper-K\"ahler () target spaces
and check they preserve 1/2 of the supersymmetry. We show how these solitons
are realised in M theory as M2-branes wrapping holomorphic 2-cycles in the
\bE^{1,2}\times {HK}_8 background. Using the -symmetry of a probe
M2-brane in this background we determine the supersymmetry they preserve, and
note that there is a discrepancy in the fraction of supersymmetry preserved by
these solitons as viewed from the low energy effective sigma model description
of the M2-brane dynamics or the full M theory. Toric manifolds are
dual to a Hanany-Witten setup of D3-branes suspended between 5-branes. In this
picture the lumps correspond to vortices of the three dimensional or theory.Comment: 12+1 pages. LaTex. v2: Typos corrected and references adde
Feynman Path Integral on the Noncommutative Plane
We formulate Feynman path integral on a non commutative plane using coherent
states. The propagator for a free particle exhibits UV cut-off induced by the
parameter of non commutativity.Comment: 7pages, latex 2e, no figures. Accepted for publication on J.Phys.
D=2, N=2, Supersymmetric theories on Non(anti)commutative Superspace
The classical action of a two dimensional N=2 supersymmetric theory,
characterized by a general K\"{a}hler potential, is written down on a
non(anti)commutative superspace. The action has a power series expansion in
terms of the determinant of the non(anti)commutativity parameter
. The theory is explicitly shown to preserve half of the N=2
supersymmetry, to all orders in (det C)^n. The results are further generalized
to include arbitrary superpotentials as well.Comment: 32 pages, Latex; v2:minor typos corrected and a reference adde
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