
Feb 24 2012
UKZN Node Seminar:
Prof S G Ghosh
Astrophysics and Cosmology Research Unit in conjunction with NITheP
cordially invites you to a seminar by:
SPEAKER: Prof S G Ghosh, Centre for Theoretical Physics, Jamia Millia Islamia, New Delhi
TITLE: Gravitational collapse in 5D EinsteinGaussBonnet gravity
DATES: 24 February 2012
TIME: 13.15 pm – 14:15 pm
VENUE: Physics seminar room, H block, 3rd rd floor, Physics, University of KwaZuluNatal (Westville Campus)
Abstract:
We consider a Lemaitre  Tolman  Bondi type spacetime in Einstein gravity with the Gauss
Bonnet combination of quadratic curvature terms, and present exact solutions in closed form.
It turns out that the presence of the coupling constant of the GaussBonnet terms $alpha > 0$
completely changes the causal structure of the singularities from the analogous general
relativistic case. The gravitational collapse of inhomogeneous dust in the fivedimensional
GaussBonnet extended Einstein equations leads to formation of a massive, but weak, timelike
singularity which is forbidden in general relativity. Interestingly, this is a counterexample to
three conjectures: cosmic censorship conjecture, hoop conjecture and Seifert's conjecture.
Refreshments will served at 12:30pm
contact
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 Ms Monique Louw
National Institute for Theoretical Physics
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 NITheP Gauteng node
 Rene Kotze (contact person for the NITheP WITS node)
Physical address: University of Witwatersrand
School of Physics
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Braamfontein
JHB
 Phone: 27 (0)218082653  Fax: 27 (0)218083862
 NITheP KZN node
 Ms Nelisiwe Mncube
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4000
South Africa
 Phone: 27 (0)31 260 7570  Fax: 27 (0)31 260 8090
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