ar X iv : 0 80 5 . 45 05 v 1 [ gr - q c ] 2 9 M ay 2 00 8 Kerr initial data

ar X iv : 0 80 5 . 45 05 v 2 [ gr - q c ] 1 5 A ug 2 00 8 Kerr initial data

Exploiting a 3+1 analysis of the Mars-Simon tensor, conditions on a vacuum initial data set ensuring that its development is isometric to a subset of the Kerr spacetime are found. These conditions are expressed in terms of the vanishing of a positive scalar function defined on the initial data hypersurface. Applications of this result are discussed. PACS numbers: 04.20.Ex, 04.20-q, 04.70-s Subm...

ar X iv : 0 80 5 . 28 58 v 1 [ gr - q c ] 1 9 M ay 2 00 8 DISCRETE DIFFERENTIAL FORMS FOR COSMOLOGICAL SPACE - TIMES

In this article we describe applications of the numerical method of discrete differential forms in computational GR. In particular we consider the initial value problem for vacuum space-times that admit plane gravitational waves. As described in an earlier paper the discrete differential form approach can provide accurate results in spherically symmetric space-times [28]. Moreover it is manifes...

ar X iv : 0 71 2 . 38 38 v 3 [ gr - q c ] 3 1 M ay 2 00 8 General Transformation Formulas for Fermi - Walker Coordinates

ar X iv : 0 80 5 . 45 13 v 1 [ m at h . A G ] 2 9 M ay 2 00 8 Involutions on surfaces with p g = q = 1

In this paper some numerical restrictions for surfaces with an involution are obtained. These formulas are used to study surfaces of general type S with pg = q = 1 having an involution i such that S/i is a non-ruled surface and such that the bicanonical map of S is not composed with i. A complete list of possibilities is given and several new examples are constructed, as bidouble covers of surf...

ar X iv : h ep - e x / 05 05 05 0 v 2 1 9 M ay 2 00 5 CLEO RESULTS ON TRANSITIONS IN HEAVY QUARKONIA a

Recent CLEO results on electromagnetic and hadronic transitions in charmonium and bot-tomonium systems are reviewed.