Found 6 result(s)

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.