Found 3 result(s)

### 27.05.2015 (Wednesday)

#### Entanglement Entropy in Massive Quantum Field Theories

Regular Seminar Olalla Castro Alvaredo (City U.)

 at: 14:00 ICroom B1004 abstract: In this talk I will review some of the main results of my research in this area, which stated in 2007 in collaboration with John L. Cardy and Benjamin Doyon. I will emphasise how a special type of field we have named branch point twist field has become an essential tool for performing computations of the entanglement entropy in non-critical systems. I will show how the relationship between correlators of twist fields and entanglement entropy allows us to recover well-known results for critical systems but also to predict new results for theories with a finite correlation length. Time permitting, I will mention some more recent results extending our understanding to non-unitary critical and non-critical systems.

### 16.01.2008 (Wednesday)

#### The Homogeneous and Symmetric Space Sine-Gordon Models: a Review

Regular Seminar Olalla Castro Alvaredo (City University London)

 at: 14:00 ICroom Huxley 503 abstract: The homogeneous and symmetric space sine-Gordon models (HSG- and SSSG-models, for short) are two groups of two-dimensional integrable quantum field theories which belong to a larger class of models: the non-Abelian affine Toda field theories. In this talk I intend to review the main results known up to date about these two classes of models, paying special attention to my own contributions to the subject. These contributions have focused on the one hand, on the development of the bootstrap program for the HSG-models (TBA-analysis, computation of form factors and correlation functions etc) and, on the other hand, on the study of the quantum integrability and spectrum of a subset of the SSSG-models, known as split models.

### 25.10.2004 (Monday)

#### Correlation functions from spin chains with impurities

Triangular Seminar Olalla Castro-Alvaredo (Ecole Normale Superieure de Lyon)

 at: 15:00 City U.room Geary Room CM524 abstract: In this talk I will present a short review on the algebraic Bethe ansatz technique and on the recently found solution of the so-called inverse problem. I will show how this solution provides a means for the explicit and exact computation of correlation functions in spin chains and summarize some of the many results obtained in this direction by members of the theory group at the ENS-Lyon in the last years. Finally I will present some work still in progress which intends the generalization of these techniques to the case of spin chains in the presence of impurities.