Zobrazeno 1 - 10
of 559
pro vyhledávání: '"FRANCAVIGLIA M"'
Publikováno v:
IJGMMP Vol. 10, No. 1 (2013) 1220024 (10 pages)
We consider systems of local variational problems defining non vanishing cohomolgy classes. In particular, we prove that the conserved current associated with a generalized symmetry, assumed to be also a symmetry of the variation of the corresponding
Externí odkaz:
http://arxiv.org/abs/1512.03176
Publikováno v:
Journal of Physics. Conf. Series, 474 (2013) 012017
We study cohomological obstructions to the existence of global conserved quantities. In particular, we show that, if a given local variational problem is supposed to admit global solutions, certain cohomology classes cannot appear as obstructions. Vi
Externí odkaz:
http://arxiv.org/abs/1310.1691
Autor:
Fatibene, L., Francaviglia, M.
We shall show that although Palatini f(R)-theories are equivalent to Brans-Dicke theories, still the first pass the Mercury precession of perihelia test, while the second do not. We argue that the two models are not physically equivalent due to a dif
Externí odkaz:
http://arxiv.org/abs/1302.2938
Autor:
Corona, S.P., Roviello, G., Strina, C., Milani, M., Madaro, S., Zanoni, D., Allevi, G., Aguggini, S., Cappelletti, M.R., Francaviglia, M., Azzini, C., Cocconi, A., Sirico, M., Bortul, M., Zanconati, F., Giudici, F., Rosellini, P., Meani, F., Pagani, O., Generali, D.
Publikováno v:
In The Breast August 2019 46:19-24
We shall show that no reductive splitting of the spin group exists in dimension 3 \leq m \leq 20 other than in dimension m = 4. In dimension 4 there are reductive splittings in any signature. Euclidean and Lorentzian signatures are reviewed in partic
Externí odkaz:
http://arxiv.org/abs/1206.3689
Publikováno v:
International Journal of Geometric Methods in Modern Physics Vol. 9, No. 8 (2012) 1250072 (18 pages)
We discuss in a critical way the physical foundations of geometric structure of relativistic theories of gravity by the so-called Ehlers-Pirani-Schild formalism. This approach provides a natural interpretation of the observables showing how relate th
Externí odkaz:
http://arxiv.org/abs/1202.5699
Autor:
Fatibene, L., Francaviglia, M.
We shall investigate the consequences of non-trivial Weyl geometries on conservation laws of a fluid. In particular we shall obtain a set of properties which allow to obtain in this generalized setting the standard relation between conservation of th
Externí odkaz:
http://arxiv.org/abs/1109.4115
It is shown that when in a higher order variational principle one fixes fields at the boundary leaving the field derivatives unconstrained, then the variational principle (in particular the solution space) is not invariant with respect to the additio
Externí odkaz:
http://arxiv.org/abs/1106.3738
We shall here discuss a characterization of geodesics trajectories. We shall show that the action of the gravitational field on mass particles can be essentially identified with the force that cannot be absolutely eliminated. This leads to an alterna
Externí odkaz:
http://arxiv.org/abs/1106.2221
Autor:
Fatibene, L., Francaviglia, M.
In view of Ehlers-Pirani-Schild formalism, since 1972 Weyl geometries should be considered to be the most appropriate and complete framework to represent (relativistic) gravitational fields. We shall here show that in any given Lorentzian spacetime (
Externí odkaz:
http://arxiv.org/abs/1106.1961