1,830 research outputs found
Off-shell N=(4,4) supersymmetry for new (2,2) vector multiplets
We discuss the conditions for extra supersymmetry of the N=(2,2)
supersymmetric vector multiplets described in arXiv:0705.3201 [hep-th] and in
arXiv:0808.1535 [hep-th]. We find (4,4) supersymmetry for the semichiral vector
multiplet but not for the Large Vector Multiplet.Comment: 15 page
Linearizing Generalized Kahler Geometry
The geometry of the target space of an N=(2,2) supersymmetry sigma-model
carries a generalized Kahler structure. There always exists a real function,
the generalized Kahler potential K, that encodes all the relevant local
differential geometry data: the metric, the B-field, etc. Generically this data
is given by nonlinear functions of the second derivatives of K. We show that,
at least locally, the nonlinearity on any generalized Kahler manifold can be
explained as arising from a quotient of a space without this nonlinearity.Comment: 31 pages, some geometrical aspects clarified, typos correcte
Generalized Kahler manifolds and off-shell supersymmetry
We solve the long standing problem of finding an off-shell supersymmetric
formulation for a general N = (2, 2) nonlinear two dimensional sigma model.
Geometrically the problem is equivalent to proving the existence of special
coordinates; these correspond to particular superfields that allow for a
superspace description. We construct and explain the geometric significance of
the generalized Kahler potential for any generalized Kahler manifold; this
potential is the superspace Lagrangian.Comment: 21 pages; references clarified and added; theorem generalized; typos
correcte
Microhistological Analysis of Cows\u27 Diet during a Severe Drought in the Semi Arid Region of North Patagonia (Argentina)
The continuous use of the livestock fields of the Middle Valley of Río Negro, North Patagonia, Argentina, combined with adverse weather conditions that occur periodically, have contributed to the degradation of rangelands. The historical annual average rainfall regime in the Valle Medio of Río Negro is 303 mm but between 2002 and 2011, the average deficit was 33%. According to the Rural Society of Choele Choel, due to the decreased forage on offer, the existence of cattle in 2011 dropped to 85,000 animals, representing 50% of the normal amount for the area. During these critical times of drought, when grasslands decrease in quantity and quality, shrubs are supposed to contribute to the diet of cattle in this area.
Knowledge of the diet of grazing animals is important in developing management standards that allow the proper use of natural grasslands. The utilization of epidermal characteristics to identify plant components in esophageal, ruminal, or fecal samples is a widespread technique used to study diet composition of free-ranging herbivores (Holechek et al. 1982, Bóo et al. 1993, Lindström et al. 1998).
Our study was designed to evaluate cow\u27s diet from spring (September 2011) to early summer (January 2012), a particularly difficult period for breeders, in a plot of a field in this area of north Patagonia, Argentina
Coupling of a locally implanted rare-earth ion ensemble to a superconducting micro-resonator
We demonstrate the coupling of rare-earth ions locally implanted in a
substrate (Gd in AlO) to a superconducting NbN
lumped-element micro-resonator. The hybrid device is fabricated by a controlled
ion implantation of rare-earth ions in well-defined micron-sized areas, aligned
to lithographically defined micro-resonators. The technique does not degrade
the internal quality factor of the resonators which remain above .
Using microwave absorption spectroscopy we observe electron-spin resonances in
good agreement with numerical modelling and extract corresponding coupling
rates of the order of MHz and spin linewidths of MHz.Comment: 4 pages, 2 Figure
NS-NS fluxes in Hitchin's generalized geometry
The standard notion of NS-NS 3-form flux is lifted to Hitchin's generalized
geometry. This generalized flux is given in terms of an integral of a modified
Nijenhuis operator over a generalized 3-cycle. Explicitly evaluating the
generalized flux in a number of familiar examples, we show that it can compute
three-form flux, geometric flux and non-geometric Q-flux. Finally, a
generalized connection that acts on generalized vectors is described and we
show how the flux arises from it.Comment: 21 pages, 1 figure; v3: minor change
An Alternative Topological Field Theory of Generalized Complex Geometry
We propose a new topological field theory on generalized complex geometry in
two dimension using AKSZ formulation. Zucchini's model is model in the case
that the generalized complex structuredepends on only a symplectic structure.
Our new model is model in the case that the generalized complex structure
depends on only a complex structure.Comment: 29 pages, typos and references correcte
Covariant Harmonic Supergraphity for N = 2 Super Yang--Mills Theories
We review the background field method for general N = 2 super Yang-Mills
theories formulated in the N = 2 harmonic superspace. The covariant harmonic
supergraph technique is then applied to rigorously prove the N=2
non-renormalization theorem as well as to compute the holomorphic low-energy
action for the N = 2 SU(2) pure super Yang-Mills theory and the leading
non-holomorphic low-energy correction for N = 4 SU(2) super Yang-Mills theory.Comment: 17 pages, LAMUPHYS LaTeX, no figures; based on talks given by I.
Buchbinder and S. Kuzenko at the International Seminar ``Supersymmetries and
Quantum Symmetries'', July 1997, Dubna; to be published in the proceeding
Harmonic Superspaces in Low Dimensions
Harmonic superspaces for spacetimes of dimension are constructed.
Some applications are given.Comment: 16, kcl-th-94-15. Two further references have been added (12 and 13)
and a few typographical errors have been correcte
A refined Razumov-Stroganov conjecture
We extend the Razumov-Stroganov conjecture relating the groundstate of the
O(1) spin chain to alternating sign matrices, by relating the groundstate of
the monodromy matrix of the O(1) model to the so-called refined alternating
sign matrices, i.e. with prescribed configuration of their first row, as well
as to refined fully-packed loop configurations on a square grid, keeping track
both of the loop connectivity and of the configuration of their top row. We
also conjecture a direct relation between this groundstate and refined totally
symmetric self-complementary plane partitions, namely, in their formulation as
sets of non-intersecting lattice paths, with prescribed last steps of all
paths.Comment: 20 pages, 4 figures, uses epsf and harvmac macros a few typos
correcte
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