[LORENE] Tensor calculus

[Eric Gourgoulhon]

The tensor calculus (covariant derivatives with respect
to an arbitrary metric, computation of Ricci tensor,
etc...) is ready in the new classes Tensor, Metric and
Connection. Both spherical and Cartesian components
of tensor fields can be used.

An example of usage is provided by the main code

    Lorene/Codes/Test/Metric/test_kerr.C

which computes the ten Einstein equations for
the Kerr metric in quasi-isotropic coordinates (both
in spherical and Cartesian components) and
checks whether they are satisfied.
Four domains are used, with the horizon located
at the boundary between the nucleus (domain #0)
and the first shell (domain #1). The last domain
(domain #3) is compactified, i.e. extends up to
spatial infinity.

Best wishes,

    Eric.

-- 
Eric Gourgoulhon
Laboratoire de l'Univers et de ses THeories (LUTH)
UMR 8102 du CNRS / Observatoire de Paris, F-92195 Meudon Cedex, France
tel: +33 1.45.07.74.33 (secretariat : +33 1.45.07.75.10)
e-mail: Eric.Gourgoulhon/at/obspm.fr    WWW: http://www.luth.obspm.fr/