Found 6 result(s)

18.02.2015 (Wednesday)

1408' style='color:#f0ad4e'>

Revisiting soliton contributions to perturbative amplitudes

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

at:
13:15 KCL
room 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)

961' style='color:#f0ad4e'>

M5's, D4's and 5D SYM

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

at:
15:30 IC
room 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)

953' style='color:#f0ad4e'>

M5's, D4's and 5D SYM

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

at:
13:15 KCL
room 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)

928' style='color:#f0ad4e'>

Supersymmetric 3-algebra theories in 6 dimensions

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

at:
14:00 IC
room 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)

833' style='color:#f0ad4e'>

Connections between U(N)xU(N) and SU(N)xSU(N) Membrane Theories

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

at:
13:15 KCL
room 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)

668' style='color:#f0ad4e'>

Higgsing M2 worldvolume theories

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

at:
11:00 QMW
room 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