15-18 September 2014

Dept. of Physics and Astronomy

Europe/Rome timezone

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Displaying 25
contributions
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25

The scalar products and certain correlation functions of models solvable by the quantum separation of variables
can be expressed in terms of $N$-fold multiple integrals which can be thought of as the partition function of a one dimensional
gas of particles trapped in an external potential $V$ and interacting through repulsive two-body interactions of the type
$\ln \big[ \sinh[\pi \om_1(\la-\m
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Presented by Dr. Karol KOZLOWSKI
on
15 Sep 2014
at
16:30

The discovery of integrability in the planar limit of AdS/CFT has
triggered a renewed interest toward the study of finite-size corrections of exactly solvable systems. In this talk, I will present a very recent idea which has made possible the reduction of the complicated Thermodynamic Bethe Ansatz equations for the anomalous dimensions of composite operators in $AdS_5/CFT_4$ and in $Ad
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Presented by Roberto TATEO
on
16 Sep 2014
at
11:00

I am going to present some results about (p,q) Minimal Liouville gravity.
It is assumed that the generating function of the correlators in genus zero in Minimal Liouville gravity (MLG) is nothing but logarithm of the Sato tau-function for dispersionless Gefand-Dikii hierarchy with the special initial condition given by Douglas string equation.
Using the connection between MLG and Frobenious
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Presented by Prof. Alexander BELAVIN
on
15 Sep 2014
at
10:00

In this talk I will show that the entanglement entropy of a region of large size ℓ in a one-dimensional non-unitary critical model behaves as S∼(ceff/3)logℓ, where ceff=c−24Δ>0 is the effective central charge, c (which may be negative) is the central charge of the conformal field theory and Δ≤0 is the lowest holomorphic conformal dimension in the theory. This result generalize the well
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Presented by Dr. Benjamin DOYON
on
17 Sep 2014
at
09:00

We present a new approach to computing energy flow correlations in a generic CFT. These infrared finite observables are familiar from collider physics studies and describe the angular distribution of energy in outgoing radiation created from the vacuum by some source. The energy correlations can be expressed in terms of Wightman correlation functions in a certain limit. We explain how to compute t
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Presented by Gregory KORCHEMSKY
on
15 Sep 2014
at
14:30

Presented by Dr. Robert WESTON
on
17 Sep 2014
at
14:30

We will consider interfaces of systems of classical statistical mechanics in two dimensions. Interfaces at criticality are conformally invariant random curves and SLE together with field theory have been successfully applied to several models. On the other hand, below criticality exact results are available only from lattice calculations which are restricted to the Ising model, a circumstance that
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Presented by Alessio SQUARCINI
on
18 Sep 2014
at
10:00

We compute the null cusp anomalous dimension of ABJM theory at strong coupling up to two-loop order. This is done by evaluating corrections to the corresponding superstring partition function, weighted by the AdS4xCP3 action in AdS light-cone gauge. We compare our result, where we use an anomalous shift in the AdS4 radius, with the cusp anomaly of N=4 SYM, and extract the two-loop contribution to
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Presented by Mr. Edoardo VESCOVI
on
15 Sep 2014
at
14:10

We study the asymptotic behaviour of the dynamical correlation functions of massless quantum integrable models. We develop an approach based on the summation of the appropriate (critical) form factors. We show that this approach gives rise to a number of new hypergeometric identities. These identities lead to the leading terms of the asymptotics for the two-point and multi-point correlation funct
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Presented by Prof. Nikolai KITANINE
on
16 Sep 2014
at
12:00

We map a system of one-dimensional guides containing bosons with strongly repulsive interaction onto the topological Kondo model. We study the thermodynamic properties by computing the ground state energy and the temperature dependence of the free energy shift due to the junction.

Presented by Dr. Francesco BUCCHERI
on
15 Sep 2014
at
13:50

Correlations after quantum quenches in the XXZ spin chain: Failure of the Generalized Gibbs Ensemble

In closed integrable systems, thermalization after a quantum quench is precluded by the existence of infinitely many conserved charges. The idea of the generalized Gibbs ensemble (GGE) is to include all local conserved charges into the canonical density operator with appropriate Lagrange-multipliers to ensure conservation of local charges. It is a nontrivial question whether the GGE correctly desc
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Presented by Mr. Márton MESTYáN
on
16 Sep 2014
at
16:30

Excited state entanglement in conformal field theory: extensivity and the role of microscopic detail

We study the excited state subsystem purity (equivalent to 2nd Renyi entropy) as a measure of entanglement in 1+1d conformal field theories. In order to access the highly excited states we generalize the replica approach and develop a systematic framework to treat arbitrary states (in particular descendants) by means of novel CFT techniques including transformation of descendant fields under confo
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Presented by Tamas Vencel PALMAI
on
17 Sep 2014
at
16:30

We generalize the idea of 1307.6856 to build conformal blocks of a generic CFT (in dimension d>2) using a recurrence relation, idea which has roots in a paper by Zamolodchikov (1984) originally applied to Virasoro blocks in 2 dimensions.
Generalizing this construction we are able to find a recurrence relation to build conformal blocks associated to the four point function of vector operators.

Presented by Mr. Emilio TREVISANI
on
17 Sep 2014
at
16:00

We discuss a connection between classical (1+1)-dimensional A_{n}^{(1)} affine Toda field theories (ATFTs) and Bethe Ansatz systems. We show that the connection coefficients for specific solutions of the associated linear problem for the classical ATFTs satisfy certain functional relations. This way we enlarge the so-called ODE/IM correspondence.
Based on: P. Adamopoulou, C. Dunning 2014 Bethe
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Presented by Dr. Panagiota ADAMOPOULOU
on
16 Sep 2014
at
10:00

Interactions are known to have dramatic effects on bosonic gases in low dimension: Not only does the ground state transform from a condensate-like state to an effective Fermi sea, but new fundamental excitations are predicted to appear which do not have any higher-dimensional equivalents. In this work, we trace these elusive excitations via their effects on the dynamical structure factor of arrays
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Presented by Milosz PANFIL
on
16 Sep 2014
at
16:00

We propose a new type of experimentally feasible quantum quench protocol. A quantum system is prepared in a coherent, localized excited state of a Hamiltonian, whose interaction strength is characterized by a control parameter. At some point during the evolution of this solitonic excitation, the parameter is suddenly changed. We study the dynamics of solitons after this global quench in a semi-cla
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Presented by Fabio FRANCHINI
on
15 Sep 2014
at
16:00

Presented by Prof. German SIERRA
on
18 Sep 2014
at
09:00

Presented by Dr. Nikolay GROMOV
on
16 Sep 2014
at
09:00

I will discuss in simple terms some topics emerging from recent
studies of quantum systems driven away from equilibrium. Particular
emphasis will be given to the integrable/non-integrable nature of the
Hamiltonian and to its local properties.

Presented by Giuseppe MUSSARDO
on
16 Sep 2014
at
14:30

Presented by Prof. Paul PEARCE
on
18 Sep 2014
at
11:00

Recently an efficient numerical method has been developed to implement crossing symmetry and unitarity on the operator dimensions and on OPE coefficients in CFTs in various dimensions.
These calculations can be done only for theories lying at the boundary of the allowed parameter space. I illustrate an alternative method that can be applied to a larger class of CFTs, whether unitary or not, thoug
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Presented by Ferdinando GLIOZZI
on
17 Sep 2014
at
11:30

In this talks I will present new (unpublished) results regarding the entanglement entropy of one of the simplest integrable models: the Lee-Yang theory. Despite its simplicity, the Lee-Yang theory is non-unitary. One of the most famous consequences of this non-unitarity was the realization by Zamolodchikov that the form factor expansion of correlation functions is now given in terms of an alternat
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Presented by Dr. Olalla CASTRO ALVAREDO
on
17 Sep 2014
at
11:00

We analytically evaluate the R ́enyi entropy for the Forrester-Baxter RSOS models in the regime III. These models are lattice realisations of non-unitary minimal models of CFT. By studying the leading term of this expression it is possible to probe conformal properties of the ground state. Our results agree completely with recent CFT redictions for the entanglement entropy of non-unitary systems.
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Presented by Mr. Davide BIANCHINI
on
17 Sep 2014
at
10:00

Within the framework of the AdS_5 /CFT_4 correspondence,
the GKP string living on a AdS_5 ⊗ S^5 background finds a counterpart in
the antiferromagnetic vacuum state for the spin chain, fruitfully employed to
investigate the dual N = 4 SYM superconformal gauge theory. Integrability
underlying such a model allows us to analyse the excitations over the vacuum
considered, by computing their sca
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Presented by Simone PISCAGLIA
on
15 Sep 2014
at
13:30

Presented by Konstantin ZAREMBO
on
15 Sep 2014
at
11:30