APRESENTAÇÃO N. 31 / PRESENTATION N. 31

N = 31, D = 11

We show that eleven-dimensional supergravity backgrounds with thirty one supersymmetries, N = 31, admit an additional Killing spinor and so they are locally isometric to maximally supersymmetric ones. This rules out the existence of simply connected eleven-dimensional supergravity preons. We also show that N = 15 solutions of type I supergravities are locally isometric to Minkowski spacetime. T...

N body simulations of the nucleus of M 31

We test through stellar N-body simulations some scenarios to explain the dynamics of the peculiar nucleus of the Andromeda galaxy (M 31): although HST observations reveal a double nucleus morphology, the rotation field is almost symmetric around the bulge gravity centre and the velocity dispersion is off-centred. We show that any m = 1 perturbation has a very short lifetime (a few 10 5 yr). Ass...

ASTROPHYSICS N body simulations of the nucleus of M 31

We test through stellar N-body simulations some scenarios to explain the dynamics of the peculiar nucleus of the Andromeda galaxy (M 31): although HST observations reveal a double nucleus morphology, the rotation field is almost symmetric around the bulge gravity centre and the velocity dispersion is off-centred. We show that any m = 1 perturbation has a very short lifetime (a few 10 5 yr). Ass...

31-3

Competing [ 2 + 31 and [ 4 + 31 Cycloadditions of C , N - Diphenylnitrone with 1 , 3 - Dienes . Evidence for Thermally Nonequilibrated Intermediatest

at -78 "C for 4 h. To the mixture was added a solution of compound 14 (5.0 mmol) and AlCl, (5.0 mmol) in CH2C12 (15 mL) dropwise. The mixture was stirred at -78 "C for 4 h and allowed to warm to room temperature. The mixture was hydrolyzed with water and extracted three times with ether. The ether phase was washed with brine, dried (MgSO,), and filtered. The filtrate was evaporated and the resi...