Theoretical Physics Colloquium
The strongly coupled quark gluon plasma and the AdS/CFT correspondence
by Prof. Aninda Sinha (Centre for High Energy Physics, IISc, Bangalore)
Tuesday, May 22, 2012
from
to
(Asia/Kolkata)
at Colaba Campus ( AG69 )
at Colaba Campus ( AG69 )
Description |
Ordinary matter is made of neutrons and protons which are themselves made of confined quarks and gluons. At very high temperatures and/or very high densities, quarks and gluons are deconfined and form a phase of matter called the quark gluon plasma. This phase of matter is thought to have existed in the early universe, a few microseconds after the big bang. In order to form and probe this state of matter, physicists have collided heavy ions at very high energies in accelarators. One property of this phase that has emerged is that it is a very good liquid. As a measure of its perfectness, one can indirectly measure the ratio of shear viscosity to entropy density. It turns out to be smaller than any other liquid known to us. Theoretically, it is very difficult to compute this ratio from first principles. It is also hard to explain and predict other properties of this phase of matter. This is where gauge/gravity duality in the form of the AdS/CFT correspondence may have a role to play. Using this correspondence, we can probe properties of strongly coupled plasmas. Although these plasmas are not the QCD plasma, some of their properties work out to be quite similar. It is an ongoing program to see how far we can stretch the correspondence to reproduce qualitative and quantitative properties of the QCD plasma. I will review and discuss what the current status of this program is. |