Triangle Seminars
Tuesday, 27 Oct 2015
tba
Tobias Galla
(Manchester)
Wednesday, 28 Oct 2015
Ambitwistor strings and the scattering equations at one loop
📍 London
Lionel Mason
(Oxford University)
Abstract:
Ambitwistor strings are holomorphic string theories whose target space is the space of complex null geoedesics in complexified space-times. I will explain how these theories explain the origin of the scattering equations in twistor strings and the CHY formulae in arbitrary dimensions and provide a reformulation of standard gauge, gravity and other theories in a holomorphic infinite tension analogue of conventional string theories. I will show how these results extend to 1-loop both on a torus and on a nodal Riemann sphere, and perhaps to higher loops.
Ambitwistor strings are holomorphic string theories whose target space is the space of complex null geoedesics in complexified space-times. I will explain how these theories explain the origin of the scattering equations in twistor strings and the CHY formulae in arbitrary dimensions and provide a reformulation of standard gauge, gravity and other theories in a holomorphic infinite tension analogue of conventional string theories. I will show how these results extend to 1-loop both on a torus and on a nodal Riemann sphere, and perhaps to higher loops.
Posted by: KCL
Knots in 3d-3d Correspondence
Masahito Yamazaki
(Kavli IPMU)
Abstract:
I will discuss knot-like defects in CS theory with complex
gauge group SL(N), in the context of its connection with 3d N=2 theory (the so-called 3d-3d correspondence). I am hoping to discuss this problem from a number of different
perspectives, including cluster algebras, state-integral models, 3d N=2 non-Abelian gauge theories, 5d N=2 SYM,
and holographic dual, and discuss the consistency checks as well as new predictions/implications. This talk is mostly based on my recent papers with D. Gang, N. Kim and M. Romo.
I will discuss knot-like defects in CS theory with complex
gauge group SL(N), in the context of its connection with 3d N=2 theory (the so-called 3d-3d correspondence). I am hoping to discuss this problem from a number of different
perspectives, including cluster algebras, state-integral models, 3d N=2 non-Abelian gauge theories, 5d N=2 SYM,
and holographic dual, and discuss the consistency checks as well as new predictions/implications. This talk is mostly based on my recent papers with D. Gang, N. Kim and M. Romo.
Posted by: IC
Thursday, 29 Oct 2015
The (2,0) superconformal bootstrap
Balt van Rees
(Durham)
Abstract:
In recent years we have witnessed a revival of the conformal bootstrap approach to CFTs. I will discuss the application of these ideas to six-dimensional conformal field theories with (2,0) supersymmetry, focusing on the universal four-point function of stress tensor multiplets. For these theories the program splits into an analytic and a numerical component. The analytic component yields exact results but in a protected subsector. The numerical component can be used to derive bounds on OPE coefficients and scaling dimensions from the constraints of crossing symmetry and unitarity. The principal numerical result is strong evidence that the A1 theory realizes the minimal allowed central charge (c=25) for any interacting (2,0) theory. This implies that the full stress tensor four-point function of the A1 theory is the unique unitary solution to the crossing symmetry equation at c=25. For this theory, we can estimate the scaling dimensions of the lightest unprotected operators appearing in the stress tensor operator product expansion. We also find rigorous upper bounds for dimensions and OPE coefficients for a general interacting (2,0) theory of central charge c. For large c, our bounds appear to be saturated by the holographic predictions obtained from eleven-dimensional supergravity.
In recent years we have witnessed a revival of the conformal bootstrap approach to CFTs. I will discuss the application of these ideas to six-dimensional conformal field theories with (2,0) supersymmetry, focusing on the universal four-point function of stress tensor multiplets. For these theories the program splits into an analytic and a numerical component. The analytic component yields exact results but in a protected subsector. The numerical component can be used to derive bounds on OPE coefficients and scaling dimensions from the constraints of crossing symmetry and unitarity. The principal numerical result is strong evidence that the A1 theory realizes the minimal allowed central charge (c=25) for any interacting (2,0) theory. This implies that the full stress tensor four-point function of the A1 theory is the unique unitary solution to the crossing symmetry equation at c=25. For this theory, we can estimate the scaling dimensions of the lightest unprotected operators appearing in the stress tensor operator product expansion. We also find rigorous upper bounds for dimensions and OPE coefficients for a general interacting (2,0) theory of central charge c. For large c, our bounds appear to be saturated by the holographic predictions obtained from eleven-dimensional supergravity.
Posted by: QMW