1,035 research outputs found
The Spinning Particles as a Nonlinear Realizations of the Superworldline Reparametrization Invariance
The superdiffeomorphisms invariant description of - extended spinning
particle is constructed in the framework of nonlinear realizations approach.
The action is universal for all values of and describes the time evolution
of different group elements of the superdiffeomorphisms group of the
superspace. The form of this action coincides with the one-dimensional
version of the gravity action, analogous to Trautman's one.Comment: 4 pages, RevTe
On the extension of the concept of Thin Shells to The Einstein-Cartan Theory
This paper develops a theory of thin shells within the context of the
Einstein-Cartan theory by extending the known formalism of general relativity.
In order to perform such an extension, we require the general non symmetric
stress-energy tensor to be conserved leading, as Cartan pointed out himself, to
a strong constraint relating curvature and torsion of spacetime. When we
restrict ourselves to the class of space-times satisfying this constraint, we
are able to properly describe thin shells and derive the general expression of
surface stress-energy tensor both in its four-dimensional and in its
three-dimensional intrinsic form. We finally derive a general family of static
solutions of the Einstein-Cartan theory exhibiting a natural family of null
hypersurfaces and use it to apply our formalism to the construction of a null
shell of matter.Comment: Latex, 21 pages, 1 combined Latex/Postscript figure; Accepted for
publication in Classical and Quantum Gravit
Space-time defects :Domain walls and torsion
The theory of distributions in non-Riemannian spaces is used to obtain exact
static thin domain wall solutions of Einstein-Cartan equations of gravity.
Curvature -singularities are found while Cartan torsion is given by
Heaviside functions. Weitzenb\"{o}ck planar walls are caracterized by torsion
-singularities and zero curvature. It is shown that Weitzenb\"{o}ck
static thin domain walls do not exist exactly as in general relativity. The
global structure of Weitzenb\"{o}ck nonstatic torsion walls is investigated.Comment: J.Math.Phys.39,(1998),Jan. issu
Matrix geometries and fuzzy spaces as finite spectral triples
A class of real spectral triples that are similar in structure to a
Riemannian manifold but have a finite-dimensional Hilbert space is defined and
investigated, determining a general form for the Dirac operator. Examples
include fuzzy spaces defined as real spectral triples. Fuzzy 2-spheres are
investigated in detail, and it is shown that the fuzzy analogues correspond to
two spinor fields on the commutative sphere. In some cases it is necessary to
add a mass mixing matrix to the commutative Dirac operator to get a precise
agreement for the eigenvalues.Comment: 39 pages, final versio
Perfect fluid and test particle with spin and dilatonic charge in a Weyl-Cartan space
The equation of perfect dilaton-spin fluid motion in the form of generalized
hydrodynamic Euler-type equation in a Weyl-Cartan space is derived. The
equation of motion of a test particle with spin and dilatonic charge in the
Weyl-Cartan geometry background is obtained. The peculiarities of test particle
motion in a Weyl-Cartan space are discussed.Comment: 25 July 1997. - 9 p. Some corrections in the text and formulars (2.4)
and (2.8) are perfomed, the results being unchange
The variational theory of the perfect dilaton-spin fluid in a Weyl-Cartan space
The variational theory of the perfect fluid with intrinsic spin and dilatonic
charge (dilaton-spin fluid) is developed. The spin tensor obeys the classical
Frenkel condition. The Lagrangian density of such fluid is stated, and the
equations of motion of the fluid, the Weyssenhoff-type evolution equation of
the spin tensor and the conservation law of the dilatonic charge are derived.
The expressions of the matter currents of the fluid (the canonical
energy-momentum 3-form, the metric stress-energy 4-form and the dilaton-spin
momentum 3-form) are obtained.Comment: 25 July 1997. - 10 p. The variational procedure is improved, the
results being unchange
Perfect hypermomentum fluid: variational theory and equations of motion
The variational theory of the perfect hypermomentum fluid is developed. The
new type of the generalized Frenkel condition is considered. The Lagrangian
density of such fluid is stated, and the equations of motion of the fluid and
the Weyssenhoff-type evolution equation of the hypermomentum tensor are
derived. The expressions of the matter currents of the fluid (the canonical
energy-momentum 3-form, the metric stress-energy 4-form and the hypermomentum
3-form) are obtained. The Euler-type hydrodynamic equation of motion of the
perfect hypermomentum fluid is derived. It is proved that the motion of the
perfect fluid without hypermomentum in a metric-affine space coincides with the
motion of this fluid in a Riemann space.Comment: REVTEX, 23 pages, no figure
Evolution in Washington Choice of Law—A Beginning
Professor Trautman discusses Washington\u27s new most significant relationship approach to conflict of laws by examining the recent cases of Baffin and Goble in relation to traditional approaches and the Restatement (Second). Because the cases mark the beginning of an evolutionary process in Washington, the author emphasizes the need to explore, find, and articulate the relevant factors to be considered in applying the most significant relationship test. Professor Trautman gives the Washington court and bar some useful beginning points for the case-by-case development of new and better conflict of laws rules
Evolution in Washington Choice of Law—A Beginning
Professor Trautman discusses Washington\u27s new most significant relationship approach to conflict of laws by examining the recent cases of Baffin and Goble in relation to traditional approaches and the Restatement (Second). Because the cases mark the beginning of an evolutionary process in Washington, the author emphasizes the need to explore, find, and articulate the relevant factors to be considered in applying the most significant relationship test. Professor Trautman gives the Washington court and bar some useful beginning points for the case-by-case development of new and better conflict of laws rules
On Some Stability Properties of Compactified D=11 Supermembranes
We desribe the minimal configurations of the bosonic membrane potential, when
the membrane wraps up in an irreducible way over . The
membrane 2-dimensional spatial world volume is taken as a Riemann Surface of
genus with an arbitrary metric over it. All the minimal solutions are
obtained and described in terms of 1-forms over an associated U(1) fiber
bundle, extending previous results. It is shown that there are no infinite
dimensional valleys at the minima.Comment: 12 pages,Latex2e lamuphys, Invited talk at International Seminar
"Supersymetry and Quantum Symmetries", Dubn
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