Found 8 result(s)

### 29.03.2021 (Monday)

#### Lonti:Acrashcourseonthesuperconformalindex

Regular Seminar Costis au:Papageorgakis'><span class='hl'>Costis</span> Papageorgakis (QMUL)

 at: 11:15 Otherroom Online abstract: This is the live session included as part of the LonTI lecture on the Superconformal Index. Please register at https://lonti.weebly.com/registration.html to receive joining instructions for this live session which will be held via Zoom. The superconformal index is a very useful tool that allows us to probe the protected spectrum of a superconformal field theory (SCFT). After a brief review of the construction of unitary irreducible representations of the superconformal algebra, I will then motivate and give its definition for generic SCFTs before specialising to 4D N=2. Special limits of the index with additional supersymmetry, as well as applications will also be discussed. No prior knowledge of the topic is required.

### 22.03.2021 (Monday)

#### Lonti:Acrashcourseonthesuperconformalindex

Regular Seminar Costis au:Papageorgakis'><span class='hl'>Costis</span> Papageorgakis (QMUL)

 at: 10:00 Otherroom Youtube abstract: This recorded tutorial is available via youtube at https://youtu.be/L-C6Xx0uI3c. The superconformal index is a very useful tool that allows us to probe the protected spectrum of a superconformal field theory (SCFT). After a brief review of the construction of unitary irreducible representations of the superconformal algebra, I will then motivate and give its definition for generic SCFTs before specialising to 4D N=2. Special limits of the index with additional supersymmetry, as well as applications will also be discussed. No prior knowledge of the topic is required.

### 18.02.2015 (Wednesday)

#### Revisitingsolitoncontributionstoperturbativeamplitudes

Regular Seminar Costis au:Papageorgakis'><span class='hl'>Costis</span> Papageorgakis (Queen Mary University)

 at: 13:15 KCLroom G.01 abstract: It is often said that soliton contributions to perturbative processes in QFT are exponentially suppressed by a form-factor. We will provide a derivation of this form-factor by studying the soliton-antisoliton pair-production amplitude. This reduces to the calculation of a matrix element in the quantum mechanics on the soliton moduli space. We will investigate the conditions under which the latter leads to suppression. Extending this framework to instanton-solitons in five-dimensional Yang-Mills theory leaves open the possibility that such contributions will not be suppressed.

### 16.02.2011 (Wednesday)

#### M5's,D4'sand5DSYM

Triangular Seminar Costis au:Papageorgakis'><span class='hl'>Costis</span> Papageorgakis (King's)

 at: 15:30 ICroom Lecture Theatre 3 abstract: We revisit the relationship between the 6D (2, 0) M5 CFT compactified on a circle to 5D maximally supersymmetric YM Gauge Theory. We show that in the broken phase 5D SYM contains a spectrum of soliton states that can be identified with the complete KK modes of an M2 ending on the M5's. This provides evidence that the (2,0) theory on a circle is equivalent to 5D SYM with no additional UV degrees of freedom, suggesting that the latter is in fact a well-defined quantum theory and possibly finite.

### 09.02.2011 (Wednesday)

#### M5's,D4'sand5DSYM

Regular Seminar Costis au:Papageorgakis'><span class='hl'>Costis</span> Papageorgakis (King's)

 at: 13:15 KCLroom 423 abstract: We revisit the relation of the six-dimensional (2, 0) M5-brane Conformal Field Theory compactified on a circle to 5D maximally supersymmetric Yang-Mills Gauge Theory. We show that in the broken phase 5D super-Yang-Mills contains a spectrum of soliton states that can be identified with the complete Kaluza-Klein modes of an M2-brane ending on the M5-branes. This provides evidence that the (2,0) theory on a circle is equivalent to 5D super-Yang-Mills with no additional UV degrees of freedom, suggesting that the latter is in fact a well-defined quantum theory and possibly finite.

### 10.11.2010 (Wednesday)

#### Supersymmetric3-algebratheoriesin6dimensions

Regular Seminar Costis au:Papageorgakis '><span class='hl'>Costis</span> Papageorgakis (KCL)

 at: 14:00 ICroom H503 abstract: Using 3-algebras we obtain a nonabelian system of equations that furnish a representation of the (2,0)-supersymmetric tensor multiplet. The on-shell conditions are quite restrictive so that the system can be reduced to five-dimensional super-Yang-Mills theory along with six-dimensional abelian (2,0) tensor multiplets. Possible applications to D4-branes and M5-branes are discussed.

### 03.02.2010 (Wednesday)

#### ConnectionsbetweenU(N)xU(N)andSU(N)xSU(N)MembraneTheories

Regular Seminar Costis au:Papageorgakis'><span class='hl'>Costis</span> Papageorgakis (KCL)

 at: 13:15 KCLroom 423 abstract: We will discuss how by integrating out a global U(1)B gauge field, the U(n)xU(n) ABJM models at level k are equivalent to SU(n)xSU(n) N=6 Chern-Simons theories with a Zk identification on the fields and a modified flux quantisation condition, but only when n and k are relatively prime. As a consequence, the ABJM model for two M2-branes in R8 can be identified with the N=8 SU(2)xSU(2) theory at k=1. We will also argue that the original N=8 SO(4)-theory of Bagger and Lambert, without modified flux quantisation, is equivalent to the U(2)xU(2) ABJM model at k=2 and hence describes the IR fixed point of a maximally supersymmetric three-dimensional O(4) gauge theory obtained in M-theory by an R8/Z2 orbifold without torsion.

### 25.11.2008 (Tuesday)

#### HiggsingM2worldvolumetheories

Exceptional Seminar Costis au:Papageorgakis'><span class='hl'>Costis</span> Papageorgakis (TIFR, Mumbai)

 at: 11:00 QMWroom 410A abstract: I will be reviewing the details of a novel form of the Higgs mechanism, present in the context of the Bagger-Lambert and ABJM proposals for the worldvolume description of multiple parallel M2 branes. I will also discuss some of its implications as well as describe related applications. The latter will focus on the determination of four-derivative corrections to the Bagger-Lambert A_4-theory for all values of the Chern-Simons level k