4,445 research outputs found
Subspaces of a para-quaternionic Hermitian vector space
Let be a para-quaternionic Hermitian structure on the real
vector space . By referring to the tensorial presentation , we
give an explicit description, from an affine and metric point of view, of main
classes of subspaces of which are invariantly defined with respect to the
structure group of and respectively
Relativistic kinematics beyond Special Relativity
In the context of departures from Special Relativity written as a momentum
power expansion in the inverse of an ultraviolet energy scale M, we derive the
constraints that the relativity principle imposes between coefficients of a
deformed composition law, dispersion relation, and transformation laws, at
first order in the power expansion. In particular, we find that, at that order,
the consistency of a modification of the energy-momentum composition law fixes
the modification in the dispersion relation. We therefore obtain the most
generic modification of Special Relativity that preserves the relativity
principle at leading order in 1/M.Comment: Version with minor corrections, to appear in Phys. Rev.
Estudio preventivo de la displasia de cadera en 130 perros combinando el método PennHIp y la sinfisiodesis pública
Realizamos un estudio de 130 cachorros de razas superiores a 20 kg, midiendo el Ãndice de distracción mediante el método PennHip, test Bardens y de Ortolani. El resultado final es que el 70% es susceptible de sufrir displasia. Se realiza la sinfisiodesis pública juvenil y el 95% a los 7-8 meses de edad tienen una displasia grado A-B
Light-cone quantization of two dimensional field theory in the path integral approach
A quantization condition due to the boundary conditions and the
compatification of the light cone space-time coordinate is identified at
the level of the classical equations for the right-handed fermionic field in
two dimensions. A detailed analysis of the implications of the implementation
of this quantization condition at the quantum level is presented. In the case
of the Thirring model one has selection rules on the excitations as a function
of the coupling and in the case of the Schwinger model a double integer
structure of the vacuum is derived in the light-cone frame. Two different
quantized chiral Schwinger models are found, one of them without a
-vacuum structure. A generalization of the quantization condition to
theories with several fermionic fields and to higher dimensions is presented.Comment: revtex, 14 p
Completeness in supergravity constructions
We prove that the supergravity r- and c-maps preserve completeness. As a
consequence, any component H of a hypersurface {h=1} defined by a homogeneous
cubic polynomial such that -d^2 h is a complete Riemannian metric on H defines
a complete projective special Kahler manifold and any complete projective
special Kahler manifold defines a complete quaternionic Kahler manifold of
negative scalar curvature. We classify all complete quaternionic Kahler
manifolds of dimension less or equal to 12 which are obtained in this way and
describe some complete examples in 16 dimensions.Comment: 29 page
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