Le contenu de cette page n’est pas disponible en français. Veuillez nous en excuser.

Quantum Fields and Strings

This series consists of talks in the area of Quantum Fields and Strings.

Seminar Series Events/Videos

Currently there are no upcoming talks in this series.

 

Mardi déc 12, 2017
Speaker(s): 

Many researchers have been studying the time evolution of entanglement entropy in the sudden quenches where a characteristic mass scale suddenly changes. It is well-know that in these quenches, the change of entanglement entropy become thermal entropy which is proportional to a subsystem size in the late time. However, we do not know which quenches thermalize a subsystem. In our works, we have been studied the time evolution of quantum entanglement in the global quenches with finite quench rate (smooth quenches).

Collection/Series: 
Scientific Areas: 

 

Mardi nov 28, 2017

Gravitational shockwaves may signal the breakdown of effective field theory near black hole horizons. Motivated by this, I will revisit the Dray-‘t Hooft solution and explain how to generalize it to the Kerr-Newman background. In doing so I will emphasize the method of spin coefficients (the Newman-Penrose formalism) in its compacted form (the Geroch-Held-Penrose formalism).

Collection/Series: 
Scientific Areas: 

 

Mardi nov 21, 2017
Speaker(s): 

In this talk I prove that the standard notion of entanglement is not defined for gravitationally anomalous two-dimensional theories because they do not admit a local tensor factorization of the Hilbert space into local Hilbert spaces. I make this precise by combining two observations:



First, a two-dimensional CFT admits a consistent quantization on a space with boundary only if it is not anomalous.



Second, a local tensor factorization always leads to a definition of consistent, unitary, energy-preserving boundary condition.

Collection/Series: 
Scientific Areas: 

 

Jeudi nov 16, 2017
Speaker(s): 

Quantum-critical strongly correlated systems feature universal collision-dominated collective transport. Viscous electronics is an emerging field dealing with systems in which strongly interacting electrons flow like a fluid. I shall describe recent theoretical and experimental results: negative resistance, current vortices, expulsion of electric field, conductance exceeding the fundamental quantum-ballistic limit and other wonders of viscous electronics.

Nature Physics 2016, 2017,  PNAS 2017,  PhysRevLet 2017

Collection/Series: 
Scientific Areas: 

 

Mardi nov 14, 2017
Speaker(s): 

Carefully studying the singularity structure of the moduli space of vacua of super conformal field theories, provides an incredibly powerful tool to extract information about such theories. In particular I will outline a concrete, yet technically challenging, strategy to go about carrying out a classification for SCFTs with extended supersymmetry in 4d.

Collection/Series: 
Scientific Areas: 

 

Mardi nov 07, 2017
Speaker(s): 

We establish a direct connection between scattering amplitudes for bi-adjoint scalar theories and a classic polytope--the "associahedron"--known to mathematicians since the 1960s. We find an associahedron naturally living in kinematic space. The tree level scattering amplitude is simply a geometric invariant of the associahedron called its "canonical form" [2], which is a differential form on kinematic space with logarithmic singularities on the boundaries of the associahedron.

Collection/Series: 
Scientific Areas: 

 

Lundi oct 30, 2017
Speaker(s): 

I will describe a holographic solution corresponding to a traversable wormhole in AdS/CFT.  The construction involves directly coupling the boundary CFT's, and corresponds to chaos-facilitated quantum teleportation between the two sides.  It does not violate boundary causality or other fundamental physics principles.

Collection/Series: 
Scientific Areas: 

 

Mardi oct 24, 2017
Speaker(s): 

Known N=4 theories in four dimensions are characterized by a choice of gauge group, and in some cases some "discrete theta angles", as classified by Aharony, Seiberg and Tachikawa. I will review how this data, for the theories with algebra su(N), is encoded in various familiar realizations of the theory, in particular in the holographic AdS_5 \times S^5 dual and in the compactification of the (2,0) A_N theory on T^2.

Collection/Series: 
Scientific Areas: 

 

Mardi oct 17, 2017
Speaker(s): 

I discuss some aspects of boundary conformal field theories (bCFTs). I will demonstrate that free bCFTs have a universal way of satisfying crossing symmetry constraints. I will introduce a simple class of interacting bCFTs where the interaction is restricted to the boundary. Finally, I will discuss relationships between boundary trace anomalies and boundary limits of stress-tensor correlation functions.

Collection/Series: 
Scientific Areas: 

Pages