Triangle Seminars
Monday, 24 Mar 2014
Lattice Formulations of Supersymmetric Yang-Mills Theories
Anosh Joseph
(DESY)
Abstract:
Certain classes of supersymmetric Yang-Mills (SYM) theories including the well known N=4 SYM, that takes part in the AdS/CFT correspondence, can be formulated on a Euclidean spacetime lattice using the techniques of exact lattice supersymmetry. In this talk I will provide the constructions of such theories and describe how great ideas such as topological field theories, Dirac-Kahler fermions, geometric discretization all come together to create lattice SYM theories that are exact-supersymmetric, gauge-invariant, local and doubler-free on the lattice. Then I move on to discuss the recent lattice constructions of specific classes SYM theories in two dimensions, with matter in various representations.
Certain classes of supersymmetric Yang-Mills (SYM) theories including the well known N=4 SYM, that takes part in the AdS/CFT correspondence, can be formulated on a Euclidean spacetime lattice using the techniques of exact lattice supersymmetry. In this talk I will provide the constructions of such theories and describe how great ideas such as topological field theories, Dirac-Kahler fermions, geometric discretization all come together to create lattice SYM theories that are exact-supersymmetric, gauge-invariant, local and doubler-free on the lattice. Then I move on to discuss the recent lattice constructions of specific classes SYM theories in two dimensions, with matter in various representations.
Posted by: IC
Wednesday, 26 Mar 2014
Exact tachyon spectrum in AdS/CFT
📍 London
Ryo Suzuki
(Oxford)
Abstract:
Unstable string states in curved spacetime is not well-understood compared to those in the flat spacetime. We consider potentially tachyonic open string states in AdS_5xS^5 which should correspond to a determinant-like operator in N=4 super Yang-Mills by the AdS/CFT correspondence. Its conformal dimension is studied using integrability and perturbative methods in N=4 SYM. By proposing and solving the boundary thermodynamic Bethe ansatz (BTBA) equations, we find an indication that states of N=4 SYM turn into tachyonic at finite coupling where the total energy of the corresponding string becomes zero.
Unstable string states in curved spacetime is not well-understood compared to those in the flat spacetime. We consider potentially tachyonic open string states in AdS_5xS^5 which should correspond to a determinant-like operator in N=4 super Yang-Mills by the AdS/CFT correspondence. Its conformal dimension is studied using integrability and perturbative methods in N=4 SYM. By proposing and solving the boundary thermodynamic Bethe ansatz (BTBA) equations, we find an indication that states of N=4 SYM turn into tachyonic at finite coupling where the total energy of the corresponding string becomes zero.
Posted by: KCL
BPS solitons and Wilson lines
Kenny Wong
(DAMTP Cambridge)
Abstract:
This talk addresses a basic question about supersymmetric gauge theory: how does a soliton behave in the vicinity of a heavy charged object? The answer to this question is intuitive and geometrical, and can be expressed in terms of a natural connection over the soliton moduli space.
Based on 1309.2644 and 1401.6167 with David Tong.
This talk addresses a basic question about supersymmetric gauge theory: how does a soliton behave in the vicinity of a heavy charged object? The answer to this question is intuitive and geometrical, and can be expressed in terms of a natural connection over the soliton moduli space.
Based on 1309.2644 and 1401.6167 with David Tong.
Posted by: IC
Thursday, 27 Mar 2014
Towards an Effective Field Theory of Structure Formation
Valentin Assassi
(Cambridge)
Abstract:
Over the next decade, large scale structure (LSS) surveys will play an increasingly important role in the measurement of cosmological parameters and as a probe of initial conditions. Relating the observed galaxies to the physics of the early universe requires a good understanding of several late-time sources of non-linear effects. In this talk, I will explain how, looking at large scales, effective field theory (EFT) offers a natural framework to deal with these non-linearities. After reviewing the recently developed effective field theory of large scale structure, I will explain how the halo bias model - a model relating the density of dark matter halos to the underlying dark matter density - can be understood in the context of EFT. In the final part of the talk, I will show explicit computations of halo statistics and discuss their observational consequences.
Over the next decade, large scale structure (LSS) surveys will play an increasingly important role in the measurement of cosmological parameters and as a probe of initial conditions. Relating the observed galaxies to the physics of the early universe requires a good understanding of several late-time sources of non-linear effects. In this talk, I will explain how, looking at large scales, effective field theory (EFT) offers a natural framework to deal with these non-linearities. After reviewing the recently developed effective field theory of large scale structure, I will explain how the halo bias model - a model relating the density of dark matter halos to the underlying dark matter density - can be understood in the context of EFT. In the final part of the talk, I will show explicit computations of halo statistics and discuss their observational consequences.
Posted by: QMW