Friday, September 9, 2011, 2:00 pm — Small Seminar Room, Bldg. 510
Abstract: We summarize the dual gravity description for a thermal gauge theory, reviewing the key features of our holographic model of large N QCD and elaborating on some new results. The theory has matter in the fundamental representation and the gauge coupling runs logarithmically with energy scale at low energies. At the highest energies the theory becomes approximately scale invariant, much like what we would expect for large N QCD although not with asymptotic freedom. In this limit the theory has a gravity dual captured by an almost classical supergravity description with a controlled quantum behavior, such that by renormalizing the supergravity action, we can compute the stress tensor of the dual gauge theory. From the stress tensor we obtain the shear viscosity and the entropy of the medium at a temperature T , and the violation of the bound for the viscosity to the entropy ratio is then investigated. By considering dynamics of open strings in curved spacetime described by the supergravity limit, we compute the drag and diﬀusion coeﬃcients for a heavy parton traversing the thermal medium. It is shown that both coeﬃcients have a logarithmic dependence on momentum, consistent with pQCD expectations. Finally, we study the conﬁnement/deconﬁnement mechanism for quarks by analyzing open strings in the presence of the ﬂavor seven branes. We ﬁnd linear conﬁnement of quarks at low temperatures, while at high temperatures the quarkonium states melt, a behavior consistent with the existence of a deconﬁned phase.
Hosted by: G. Beuf
7573 | INT/EXT | Events Calendar
Not all computers/devices will add this event to your calendar automatically.
A calendar event file named "calendar.ics" will be placed in your downloads location. Depending on how your device/computer is configured, you may have to locate this file and double click on it to add the event to your calendar.
Event dates, times, and locations are subject to change. Event details will not be updated automatically once you add this event to your own calendar. Check the Lab's Events Calendar to ensure that you have the latest event information.