242 research outputs found
Nilpotent Marsh and SUSY QM
We consider the nilpotent additions to classical trajectories in
supersymmetric and nonsupersymmetric theories. The condition of anilpotence of
action on some generalized solutions leads to the Witten supersymmetric
Lagrangian. The condition of anilpotence of topological charge is the same as
one of superpotential with spontaneous broken supersymmetry. We should vanish
half of Grassmann constants of integration, because in this case only we obtain
the same number of normalized bosonic and fermionic zero modes.Comment: 8 pages, Latex 2.09. Talk given at the conference in memory of V.I.
Ogievetski, Dubna, July, 1997. To be published in the Proceeding
Potentials in N=4 superconformal mechanics
Proceeding from nonlinear realizations of (super)conformal symmetries, we
explicitly demonstrate that adding the harmonic oscillator potential to the
action of conformal mechanics does not break these symmetries but modifies the
transformation properties of the (super)fields. We also analyze the possibility
to introduce potentials in N=4 supersymmetric mechanics by coupling it with
auxiliary fermionic superfields. The new coupling we considered does not
introduce new fermionic degrees of freedom - all our additional fermions are
purely auxiliary ones. The new bosonic components have a first order kinetic
term and therefore they serve as spin degrees of freedom. The resulting system
contains, besides the potential term in the bosonic sector, a non-trivial
spin-like interaction in the fermionic sector. The superconformal mechanics we
constructed in this paper is invariant under the full
superconformal group. This invariance is not evident and is achieved within
modified (super)conformal transformations of the superfields.Comment: 12 pages, PACS number: 12.60.J
Dynamics of (SUSY) AdS Space Isometry Breaking
Actions governing the dynamics of the Nambu-Goldstone modes resulting from
the spontaneous breaking of the SO(4,2) and isometries of five
dimensional anti-de Sitter space () and SUSY
spaces respectively due to a restriction of the motion to embedded four
dimensional space and four dimensional Minkowski space () probe
branes are presented. The dilatonic Nambu-Goldstone mode governing the motion
of the space probe brane into the covolume of the SUSY
space is found to be unstable. No such instablility appears in the other cases.
Gauging these symmetries leads to an Einstein-Hilbert action containing, in
addition to the gravitational vierbein, a massive Abelian vector field coupled
to gravity.Comment: 6 pages, 0 figures, to appear in Proceedings of IRGAC 2006: 2nd
International Conference on Quantum Theories and Renormalization Group in
Gravity and Cosmology, Barcelon
On the Inconsistency of Fayet-Iliopoulos Terms in Supergravity Theories
Motivated by recent discussions, we revisit the issue of whether globally
supersymmetric theories with non-zero Fayet-Iliopoulos terms may be
consistently coupled to supergravity. In particular, we examine claims that a
fundamental inconsistency arises due to the conflicting requirements which are
imposed on the -symmetry properties of the theory by the supergravity
framework. We also prove that certain kinds of Fayet-Iliopoulos contributions
to the supercurrent supermultiplets of theories with non-zero Fayet-Iliopoulos
terms fail to exist. A key feature of our discussion is an explicit comparison
between results from the chiral (or ``old minimal'') and linear (or ``new
minimal'') formulations of supergravity, and the effects within each of these
formalisms that are induced by the presence of non-zero Fayet-Iliopoulos terms.Comment: Comments: 69 pages, LaTeX, 2 figures, 7 tables. Significant new
material on conformal-compensator formalisms added, previous results
clarified and extended, references adde
Temperature dependent magnetic anisotropy in metallic magnets from an ab-initio electronic structure theory: L1_0-ordered FePt
On the basis of a first-principles, relativistic electronic structure theory
of finite temperature metallic magnetism, we investigate the variation of
magnetic anisotropy, K, with magnetisation, M, in metallic ferromagnets. We
apply the theory to the high magnetic anisotropy material, L1_0-ordered FePt,
and find its uniaxial K consistent with a magnetic easy axis perpendicular to
the Fe/Pt layering for all M and to be proportional to M^2 for a broad range of
values of M. For small M, near the Curie temperature, the calculations pick out
the easy axis for the onset of magnetic order. Our results are in good
agreement with recent experimental measurements on this important magnetic
material.Comment: 4 pages, 2 figure
Water Resources Management In Support Of Raw Region Based On Decoupling Effect
It determines the presence of the decoupling effect in the Russians raw regions materials by using water. Developed models that explain the relationship between the gross regional product and water intake. It proved no effect on the growth of water consumption in most regions of the reference commodity. Recommendations for the decoupling effect development in support of Russians raw regions
AdS_2/CFT_1, Canonical Transformations and Superconformal Mechanics
We propose a simple conformal mechanics model which is classically equivalent
to a charged massive particle propagating near the AdS_2\times S^2 horizon of
an extreme Reissner-Nordstr\"om black hole. The equivalence holds for any
finite value of the black hole mass and with both the radial and angular
degrees of freedom of the particle taken into account. It is ensured by the
existence of a canonical transformation in the Hamiltonian formalism. Using
this transformation, we construct the Hamiltonian of a N=4 superparticle on
AdS_2\times S^2 background.Comment: 10 pages, LaTe
Nonlinear supersymmetry: from classical to quantum mechanics
Quantization of the nonlinear supersymmetry faces a problem of a quantum
anomaly. For some classes of superpotentials, the integrals of motion admit the
corrections guaranteeing the preservation of the nonlinear supersymmetry at the
quantum level. With an example of the system realizing the nonlinear
superconformal symmetry, we discuss the nature of such corrections and
speculate on their possible general origin.Comment: 11 page
Reconstruction of unbroken vasculature of mouse by varying the slope of the scan plane in MRI
Reconstruction of vascular net of small laboratory animals from MRI data is associated with some problems. This paper proposes a method of MRI data processing which allows to eliminate the fragmentation of reconstructed vascular net. Problem of vessels fragmentation occurs in the case when vessels are parallel to the scanning plane. Our approach is based on multiple scanning, object under consideration is probed by several sets of parallel planes. The algorithm is applied to real MRI data of small laboratory animals and shows good results
New Super Calogero Models and OSp(4|2) Superconformal Mechanics
We report on the new approach to constructing superconformal extensions of
the Calogero-type systems with an arbitrary number of involved particles. It is
based upon the superfield gauging of non-abelian isometries of some
supersymmetric matrix models. Among its applications, we focus on the new N=4
superconformal system yielding the U(2) spin Calogero model in the bosonic
sector, and the one-particle case of this system, which is a new OSp(4|2)
superconformal mechanics with non-dynamical U(2) spin variables. The
characteristic feature of these models is that the strength of the conformal
inverse-square potential is quantized.Comment: 12 pages, talk presented by E.Ivanov at the XIII International
Conference "Symmetry Methods in Physics", Dubna, July 6-9, 200
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