Monday, Jul 06, 2015
11h00 Séminaire de physique mathématique
Séminaire de physique mathématique
Salle Claude Itzykson, Bât. 774 Orme des Merisiers
Nikita Nekrasov
Thursday, Jul 09, 2015
14h00 Soutenance de thèse de doctorat
Soutenance de thèse de doctorat
Amphi Claude Bloch, Bât. 774 Orme des Merisiers
Yunfeng JIANG
The research performed at the IPhT aims at better understanding the laws which govern our universe and its organisation. It encompasses most of the great subjects of modern theoretical physics:
The IPhT comprises about fifty permanent physicists (2/3 CEA, 1/3 CNRS), about thirty PhD students and postdocs, assisted by a support staff of about ten people. The IPhT also hosts permanently many short term visitors.
The conference "de Sitter and microstate lansdscapes in string theory" took place at IPhT from June 16 to 19, 2015. This workshop gathered 70 participants from around the world to discuss recent advances in understanding the landscapes of de Sitter spaces in string theory on one hand, and of black hole microstate geometries on the other. Both landscapes have experienced quite intense recent remodeling: on the black hole side this was driven by “fuzzball/firewall” informationtheorybased arguments that black hole solutions are only thermodynamic approximations that stop describing the physics at the scale of the horizon, where they should be replaced by horizonless geometries dual to the black hole microstates, and on the cosmology side by the realization that antibranes, which are one of the key ingredients needed to obtain a landscape of de Sitter vacua, may give rise to instabilities. 

F. David, 20150703

Singlefile diffusion is referred to the motion of many interacting particles in onedimensional channel which are so narrow that the particles can not pass each other, and as a result their sequence is preserved over time. Since its introduction more than 50 years ago, in modelling ion transport through cell membranes, the singlefile diffusion has been observed in a wide variety of systems, e.g. diffusion of large molecules in zeolites, carrier migration in super ionic conductors, sliding of proteins along DNA, and many more.The characteristic feature of singlefile diffusion is that, the variance of the displacement of a tracer particle at a time much larger than the mean collision time, scales as the squareroot of time, compared to the linear dependence in normal diffusion. This subdiffusive scaling has been demonstrated in a number of experimental realization. Comparatively, theoretical analysis has proved to be a challenging manybody problem, mostly because the motion of the ... 

F. David, 20150619

A century ago Albert Einstein used his new theory of gravity – the general relativity  for evaluating the bending angle of rays of light under the gravitational pull from the Sun. Ludovic Planté, Pierre Vanhove and their colleagues have evaluated for the first time the quantum gravity correction to this bending angle. The computation is done in the framework of the lowenergy effective field theory, which allows evaluating large distance effects by keeping only low energy fields and couplings. This contribution is universal to any theory of quantum because since it is independent of (any unknown) highenergy degrees of freedom. The quantum correction depends on the spin of the deflected massless particle, in contrast to the classical contribution. Therefore it violates the equivalence principle but preserves the fundamental symmetries of the theory on which Einstein based his theory of general relativity. "Bending of Light in Quantum Gravity", N. E. J. BjerrumBohr, John F. Donoghue, Barry R. ... 

C. Pepin, 20150408

RNA: The unknotted strands of life
Liouville Quantum Gravity on the Riemann Sphere
A new, yet faster, version of FastJet
Uncovering the spatial structure of mobility networks
Spin Vertex and 3 Point Function in AdS/CFT Correspondence