Catégorie
Phénomène critique
Publications associées (624)
Nonperturbative aspects of scattering amplitudes
Miguel Alexandre Ribeiro Correia
In this thesis we study how physical principles imposed on the S-matrix, such as Lorentz invariance, unitarity, crossing symmetry and analyticity constrain quantum field theories at the nonperturbative level. We start with a pedagogical introduction to the ...
EPFL2023Identifying Large Charge operators
Riccardo Rattazzi, Alexander Monin, Gil Badel
The Large Charge sector of Conformal Field Theory (CFT) can generically be described through a semiclassical expansion around a superfluid background. In this work, focussing on U(1) invariant Wilson-Fisher fixed points, we study the spectrum of spinning l ...
SPRINGER2023Twist Accumulation in Conformal Field Theory: A Rigorous Approach to the Lightcone Bootstrap
We prove that in any unitary CFT, a twist gap in the spectrum of operator product expansion (OPE) of identical scalar quasiprimary operators (i.e. phi x phi) implies the existence of a family of quasiprimary operators O t,l with spins l ->.infinity and twi ...
SPRINGER2023Critical properties of the quantum Ashkin-Teller chain with chiral perturbations
Frédéric Mila, Natalia Chepiga
We investigate the nature of the phase transitions in the quantum Ashkin-Teller chain in the presence of chiral perturbations. We locate the Lifshitz line separating a region of direct chiral transitions from the region where the transition is through an i ...
College Pk2023Exact quantum conformal symmetry, its spontaneous breakdown, and gravitational Weyl anomaly
The classical Lagrangian of the Standard Model enjoys the symmetry of the full conformal group if the mass of the Higgs boson is put to zero. This is a hint that conformal symmetry may play a fundamental role in the ultimate theory describing nature. The o ...
AMER PHYSICAL SOC2023Anomaly-free scale symmetry and gravity
In this Letter, we address the question of whether the conformal invariance can be considered as a global symmetry of a theory of fundamental interactions. To describe Nature, this theory must contain a mechanism of spontaneous breaking of the scale symmet ...
ELSEVIER2023The Källén-Lehmann representation in de Sitter spacetime
Manuel Loparco, Kamran Salehi Vaziri
We study two-point functions of symmetric traceless local operators in the bulk of de Sitter spacetime. We derive the Kallen-Lehmann spectral decomposition for any spin and show that unitarity implies its spectral densities are nonnegative. In addition, we ...
New York2023Metastability of the Potts Ferromagnet on Random Regular Graphs
We study the performance of Markov chains for the q-state ferromagnetic Potts model on random regular graphs. While the cases of the grid and the complete graph are by now well-understood, the case of random regular graphs has resisted a detailed analysis ...
SPRINGER2023Bootstrapping traceless symmetric O(N) scalars
Alessandro Vichi, Maria Refinetti, Marten Jan Reehorst
We use numerical bootstrap techniques to study correlation functions of traceless sym-metric tensors of O(N) with two indices ti j. We obtain upper bounds on operator dimen-sions for all the relevant representations and several values of N. We discover sev ...
SCIPOST FOUNDATION2023Cohomology in singular blocks of parabolic category O
We determine the dimensions of Ext -groups between simple modules and dual generalized Verma modules in singular blocks of parabolic versions of category O for complex semisimple Lie algebras and affine Kac-Moody algebras. ...
2023