251,565 research outputs found
Diffeomorphism Invariance and Local Lorentz Invariance
We show that diffeomorphism invariance of the Maxwell and the Dirac-Hestenes
equations implies the equivalence among different universe models such that if
one has a linear connection with non-null torsion and/or curvature the others
have also. On the other hand local Lorentz invariance implies the surprising
equivalence among different universe models that have in general different
G-connections with different curvature and torsion tensors.Comment: 19 pages, Revtex, Plenary Talk presented at VII International
Conference on Clifford Algebras and their Applications, Universite Paul
Sabatier UFR MIG, Toulouse (FRANCE), to appear in "Clifford Algebras,
Applications to Mathematics, Physics and Engineering", Progress in Math.
Phys., Birkhauser, Berlin 200
Unitary local invariance
We address unitary local (UL) invariance of bipartite pure states. Given a
bipartite state the complete
characterization of the class of local unitaries for which
is obtained.The two relevant parameters are
the rank of the matrix , , and the number of its
equal singular values, {\em i.e.} the degeneracy of the eigenvalues of the
partial traces of .Comment: Revised version. Accepted for publication Int. J. Quant. In
On Local Dilatation Invariance
The relationship between local Weyl scaling invariant models and local
dilatation invariant actions is critically scrutinized. While actions invariant
under local Weyl scalings can be constructed in a straightforward manner,
actions invariant under local dilatation transformations can only be achieved
in a very restrictive case. The invariant couplings of matter fields to an
Abelian vector field carrying a non-trivial scaling weight can be easily built,
but an invariant Abelian vector kinetic term can only be realized when the
local scale symmetry is spontaneously broken.Comment: 3 page
Lorentz Invariance in Shape Dynamics
Shape dynamics is a reframing of canonical general relativity in which time
reparametrization invariance is "traded" for a local conformal invariance. We
explore the emergence of Lorentz invariance in this model in three contexts: as
a maximal symmetry, an asymptotic symmetry, and a local invariance.Comment: v2: discussion of light cone structure added; minor typos fixed; 14
page
Ageing, dynamical scaling and conformal invariance
Building on an analogy with conformal invariance, local scale transformations
consistent with dynamical scaling are constructed. Two types of local scale
invariance are found which act as dynamical space-time symmetries of certain
non-local free field theories. The scaling form of two-point functions is
completely fixed by the requirement of local scale invariance. These
predictions are confirmed through tests in the 3D ANNNI model at its Lifshitz
point and in ageing phenomena of simple ferromagnets, here studied through the
kinetic Ising model with Glauber dynamics.Comment: Latex2e, 12 pages, 3 figures. Talk given at TH2002, Paris July 200
- …