Triangle Seminars
Monday, 28 Oct 2019
Description:
We are pleased to announce the first in this term's series of Triangle Early Researchers Seminars. These seminars are a chance for the PhD students and Postdocs in London working on String Theory and related areas to meet up and listen to an informal seminar given by one of our own. These seminars have been very well attended in previous years (formerly known as “String Theory PhDs in Londonâ€), and have provided a way for our broad community to get a little closer.
The first talk this term will be given at 6pm on 28rd October at KCL by Julius Grimminger. Julius is a second year PhD student at Imperial working under the supervision of Amihay Hanany, and he’ll talk about gauge theories on branes, and the Higgs mechanism. The plan will be the follow the talk with a trip to the pub.
We have a second speaker already lined up for this term, but could happily fit a third seminar in at some point. So if you are interested, please chat to the representative in your group! These talks are meant to be informal and relaxed. You could come and talk about what you’ve been up to, or come and give an introductory talk to something much more general. Or you could use it as an opportunity to practise a talk you’re preparing for something else. Anything goes!
Triangle Early Researchers Reps:
Enrico Andriolo (QMUL)
Julius Grimminger (Imperial)
Suvajit Majumder (City)
Rishi Mouland (KCL)
We are pleased to announce the first in this term's series of Triangle Early Researchers Seminars. These seminars are a chance for the PhD students and Postdocs in London working on String Theory and related areas to meet up and listen to an informal seminar given by one of our own. These seminars have been very well attended in previous years (formerly known as “String Theory PhDs in Londonâ€), and have provided a way for our broad community to get a little closer.
The first talk this term will be given at 6pm on 28rd October at KCL by Julius Grimminger. Julius is a second year PhD student at Imperial working under the supervision of Amihay Hanany, and he’ll talk about gauge theories on branes, and the Higgs mechanism. The plan will be the follow the talk with a trip to the pub.
We have a second speaker already lined up for this term, but could happily fit a third seminar in at some point. So if you are interested, please chat to the representative in your group! These talks are meant to be informal and relaxed. You could come and talk about what you’ve been up to, or come and give an introductory talk to something much more general. Or you could use it as an opportunity to practise a talk you’re preparing for something else. Anything goes!
Triangle Early Researchers Reps:
Enrico Andriolo (QMUL)
Julius Grimminger (Imperial)
Suvajit Majumder (City)
Rishi Mouland (KCL)
Posted by: rishi.mouland@kcl.ac.uk
Wednesday, 30 Oct 2019
Duality walls and 3d S-fold SCFTs
Noppadol Mekareeya
(INFN Milan Bicocca and Chulalongkorn U)
Abstract:
A local SL(2,Z) transformation on the Type IIB brane configuration gives rise to an interesting class of 3d superconformal field theories, known as the S-fold SCFTs. One of the interesting features of such a theory is that, in general, it does not admit a conventional Lagrangian description. Nevertheless, it can be described by a quiver diagram with a link being a superconformal field theory, known as the T(U(N)) theory. In this talk, we discuss various properties of the S-fold theories, including their supersymmetric indices, supersymmetry enhancement in the infrared, as well as several interesting dualities.
A local SL(2,Z) transformation on the Type IIB brane configuration gives rise to an interesting class of 3d superconformal field theories, known as the S-fold SCFTs. One of the interesting features of such a theory is that, in general, it does not admit a conventional Lagrangian description. Nevertheless, it can be described by a quiver diagram with a link being a superconformal field theory, known as the T(U(N)) theory. In this talk, we discuss various properties of the S-fold theories, including their supersymmetric indices, supersymmetry enhancement in the infrared, as well as several interesting dualities.
Posted by: IC
Triangular Seminar at KCL: Event shapes and the light-ray OPE in CFTs
📍 London
Alexander Zhiboedov
(CERN)
Abstract:
I will review recent progress in our understanding of light-ray operators
in abstract CFTs. Light-ray operators first appeared in QCD and were later
studied in N=4 Super Yang-Mills theory and holography by Hofman and Maldacena.
More recently, they attracted new interest due to an important role played
by the averaged null energy condition (ANEC) operator in various contexts.
However, it is only during the last few years it became possible to start developing
a more general theory of light-ray operators. I will explain a nonperturbative,
convergent operator product expansion (OPE) for null-integrated operators on
the same null plane in a CFT. I will discuss its application to energy-energy correlators
in N=4 Super Yang-Mills theory.
I will review recent progress in our understanding of light-ray operators
in abstract CFTs. Light-ray operators first appeared in QCD and were later
studied in N=4 Super Yang-Mills theory and holography by Hofman and Maldacena.
More recently, they attracted new interest due to an important role played
by the averaged null energy condition (ANEC) operator in various contexts.
However, it is only during the last few years it became possible to start developing
a more general theory of light-ray operators. I will explain a nonperturbative,
convergent operator product expansion (OPE) for null-integrated operators on
the same null plane in a CFT. I will discuss its application to energy-energy correlators
in N=4 Super Yang-Mills theory.
Posted by: oxford
Triangular Seminar at KCL: From generalized global symmetries to pulsar magnetospheres
📍 London
Nabil Iqbal
(Durham University)
Abstract:
Certain quantum field theories possess generalized global symmetries; just as ordinary global symmetries enforce the conversation of particle number, generalized global symmetries enforce the conservation of extended objects, such as strings. I will review this symmetry principle and argue that it governs the long-distance physics of conventional 4d electromagnetism, where the strings in question are magnetic field lines. I will then apply it to construct a novel effective theory for the description of strongly magnetized plasmas. One potential application of this new effective theory is to astrophysical pulsars, which are thought to be surrounded by strong magnetic fields as well as a high density of charged particles; the resulting zero temperature system is highly nonlinear. At leading order in derivatives our new effective theory agrees with the standard treatment in terms of ``force-free electrodynamics''. The inclusion of higher derivative terms however generically results in new and potentially observationally relevant effects, such as electric fields that accelerate charges to high energies along magnetic field lines. If time permits I will describe some recent work towards describing such energetic charges in terms of bosonization along magnetic field lines.
Certain quantum field theories possess generalized global symmetries; just as ordinary global symmetries enforce the conversation of particle number, generalized global symmetries enforce the conservation of extended objects, such as strings. I will review this symmetry principle and argue that it governs the long-distance physics of conventional 4d electromagnetism, where the strings in question are magnetic field lines. I will then apply it to construct a novel effective theory for the description of strongly magnetized plasmas. One potential application of this new effective theory is to astrophysical pulsars, which are thought to be surrounded by strong magnetic fields as well as a high density of charged particles; the resulting zero temperature system is highly nonlinear. At leading order in derivatives our new effective theory agrees with the standard treatment in terms of ``force-free electrodynamics''. The inclusion of higher derivative terms however generically results in new and potentially observationally relevant effects, such as electric fields that accelerate charges to high energies along magnetic field lines. If time permits I will describe some recent work towards describing such energetic charges in terms of bosonization along magnetic field lines.
Posted by: oxford