I.F.T.

Almuerzo-Seminario

(Lunch seminar)

September 15th, 4:00 p.m.

Electrogravity Duality

Naresh Dadhich

Presently visiting Dept. de Fisica Fonamental, Universitat de Barcelona from Inter-University Centre for Astronomy and Astrophysics, Pune University Campus, Pune 411007, India.

When one decomposes gravitational field into electric and magnetic parts it turns out that there are two kinds of electric parts corresponding to the two kinds of charges, the usual matter-energy and the gravitational field energy. The interesting question is to consider the duality transformation between these two electric parts in relation to the Einstein equation. Even though the vacuum equation is symmetric between them, it is possible to construct solutions dual to the well-known black hole solutions. In obtaining these solutions there remains one equation free, that is it is implied by the others. Now even if we tamper this equation the vacuum solution will not be disturbed but the modified equation would no longer be duality invariant. Now we can find solutions to the dual (modified) eqution.

The remarkable feature of the duality transformation is to incorporate global monopole charge in black hole spacetimes. That is the solution dual to the Schwarzschild black hole is the Schwarzschild black hole with global monopole charge. This can be shown to be the case for all black hole solutions. Similar to the vacuum case, it is possible to construct spacetimes dual to flat spacetime which would represent zero-mass global monopole (it could also be interpreted as uniform potential spacetime) and global texture.

It appears that the proposed duality transformation is a natural way to imbibe the Einstein vacuum/electrovac/flat spacetimes with a topological defect of global monopole and texture.

The almuerzo-seminario is intended to be an informal seminar and an open forum for discussion.

You are wellcome to bring your own bocata (sandwich), or coffee or tea.

Where: Modulo C-XVI, 3rd floor, Facultad de Ciencias U.A.M., C.U. Cantoblanco, 28049-Madrid