I will describe how correlation functions of a conformal field theory placed on the thermal geometry $S^1 \times S^2$ can be used to obtain precise information about flat space CFT data, namely the spectrum and the OPE coefficients of primary operators. The focus will be primarily on thermal one-point functions. Although exact formulas for thermal one-point blocks are not known in this...
Integrable quantum field theories with $\mathbb{Z}_n$ symmetry arise from decomposing two-body scattering amplitudes into cyclically shifted components, leading to graded S-matrices that organize asymptotic states into internal $\mathbb{Z}_n$ sectors. This framework preserves a generalized notion of braiding unitarity and crossing symmetry, and features an infinite tower of conserved charges...
The double sine-Gordon model is the non-integrable deformation of the standard sine-Gordon model caused by the cosine perturbation with the frequency reduced by the factor of 2. It was showed by Delfino and Mussardo [1], that this perturbation induces confinement of the sine-Gordon solitons, which become coupled into the ‘me- son’ bound states. I calculate [2] the meson masses in the weak...
The S-matrix bootstrap program offers a unique possibility to compute explicitly the form factors of local operators in integrable quantum field theories. We shall build on those results so as to compute, in terms of explicit series of multiple integrals, the multipoint correlation functions in the Sinh-Gordon 1+1 dimensional quantum field theory, which is a simple case where the S-matrix is...
The models known as "free fermions in disguise" are a class of Hamiltonians with very peculiar properties: while they are directly solvable by any Jordan-Wigner (JW) transformation, they display a free-fermionic spectrum. Indeed, the mapping to free fermionic modes involves a complicated non-linear and highly non-local map. Because of this, contrary to standard JW-solvable spin chains, it is a...
The 1+1-dimensional sinh-Gordon model is a well-known example of a simple and well-studied integrable QFT with factorized scattering. We consider this theory on a multi-sheeted Riemann surface with a flat metric and branch points, which are represented by twist operators $\cal T_n$. Twist operators are interesting in the context of von Neumann and Renyi entanglement entropies in the original...
The linear growth of entanglement after a quench from a state with short-range correlations is a universal feature of many body dynamics.
It has been shown to occur in integrable and chaotic systems undergoing either Hamiltonian, Floquet or circuit dynamics and has also been observed in experiments.
The entanglement dynamics emerging from long-range correlated states is far less studied,...
The Blume–Capel model, a spin chain system exhibiting a tricritical point described by a conformal field theory with central charge $c=7/10$, serves as a rich framework for studying its thermal perturbation, the $E_7$ integrable quantum field theory. In my work, I investigate both numerical and analytical aspects of the $E_7$ model, aiming to validate theoretical predictions and explore new...
The study of correlation functions of integrable models at their free fermion points often leads to representations in terms of Fredholm determinants (and their minors) of integrable integral operators. This occurs, for example, in dynamical two-point correlation functions of the impenetrable Bose gas, the XY and XX spin chains at finite temperature. In this talk, we address the problem of...
As a contribution to understanding quantum spacetimes, we consider the quantum field theory of a massive scalar field on the Fuzzy AdS spacetime in two and three dimensions. We focus on boundary correlation functions, which, in the case of the commutative AdS bulk, are given by CFT correlators. In two dimensions, the fuzzy two-point function is calculated analytically and expressed in terms of...
Quantum fidelities—like entanglement measures—originated in quantum information theory but have since become powerful probes of emergent phenomena in quantum many-body systems. In out-of-equilibrium settings, the most prominent example is the Loschmidt echo (LE), which quantifies the fidelity between an initial state and its time-evolved counterpart after a quantum quench. The LE is notably...
The quasiparticle picture provides simplest and yet most effective way to study the out-of-equilibrium evolution of entanglement measures following a quantum quench at the ballistic scale. It has found applications in the study of R´enyi entropies and negativities in free and interacting systems. I will present a novel point of view for this rather dated subject, according to which the...
