Dipartimento di Matematica -UTV-

Date	Type	Start	End	Room	Speaker	From	Title
18/12/25	Seminario	16:00	17:00	1201 Dal Passo	Pierre Bieliavsky	UC Louvain	Operator Algebras Seminar The space of star-products of a homogeneous symplectic manifold Note:This talk is part of the activity of the MUR Excellence Department Project MatMod@TOV (CUP E83C23000330006) Abstract
17/12/25	Seminario	17:10	18:10	1201 Dal Passo	Fabio Cipriani	Politecnico di Milano	Operator Algebras Seminar Existence of ground states of Hamiltonians satisfying energy-entropy inequalities Note:This talk is part of the activity of the MUR Excellence Department Project MatMod@TOV (CUP E83C23000330006) Abstract
17/12/25	Seminario	16:00	17:00	1201 Dal Passo	Edoardo D'Angelo	Università di Milano	Operator Algebras Seminar A locally covariant renormalization group in Lorentzian spacetimes Note:This talk is part of the activity of the MUR Excellence Department Project MatMod@TOV (CUP E83C23000330006) Abstract Renormalization group flows, based on functional Polchinski or Wetterich equations, are powerful tools that give access to non-perturbative aspects of strongly coupled QFTs and gravity. I will provide an overview of a new approach, developed to construct a rigorous renormalization group (RG) flow on Lorentzian manifolds. This approach, based on a local and covariant regularization of the Wetterich equation, highlights its state dependence. I give the main ideas of a proof of local existence of solutions for the RG equation, when a suitable Local Potential Approximation is considered. The proof is based on an application of the renown Nash-Moser theorem. I will also present recent applications of the locally covariant RG equation to the non-perturbative renormalizability of quantum gravity.
16/12/25	Seminario	14:30	15:30	1201 Dal Passo	Alesandro Duca	Université Lorraine-Nancy	Seminario di Equazioni Differenziali Saturation methods for the bilinear controllability of linear and nonlinear PDEs Abstract We present recent advances in the study of bilinear approximate controllability for both linear and nonlinear partial differential equations (PDEs), with a particular focus on saturation techniques. After introducing the general framework of bilinear control systems, we discuss small-time approximate controllability results obtained via bilinear controls for several models, including the nonlinear Schrödinger equation, the nonlinear heat equation, and the Burgers equation. Under suitable structural assumptions on the controls, the results demonstrate that it is possible to steer the system arbitrarily close to a desired target state, even in the presence of nonlinear dynamics. The proofs rely on the iterative application of saturation properties and on geometric arguments derived from commutator expansions. NB : This talk is part of the activity of the MUR Excellence Department Project MATH@TOV CUP E83C23000330006
12/12/25	Colloquium	15:00	16:00		Christopher J Fewster	University of York	Colloquium Levi-Civita Measurement in quantum field theory Note:This talk is part of the activity of the MUR Excellence Department Project MatMod@TOV (CUP E83C23000330006) Abstract Many presentations of quantum mechanics include a postulate that the state of a system undergoes an instantaneous change following a measurement. This is clearly incompatible with special and general relativity and raises questions concerning the description of measurement in quantum field theory (QFT). Attempts to extend measurement postulates to QFT by hand have produced pathologies, such as the "impossible measurements" described long ago by Sorkin. I will present a recent operational approach to these questions, which models measurement of one quantum field (the system) by coupling it to another (the probe). This is all accomplished in a model-independent way within algebraic quantum field theory (AQFT). The resulting framework provides a description of measurement in QFT that is causal, covariant and consistent, and includes state update rules that are derived from the formalism, and works equally well in flat or curved spacetimes. As well as covering the basics of the formalism, I will touch on some more recent developments, including links to quantum reference frames. I will not assume any prior knowledge of AQFT. The talk is mostly based on joint work with Rainer Verch (Comm. Math. Phys. 378 (2020) 851-889 arXiv:1810.06512) and further work with Henning Bostelmann, Maximilian Ruep and Ian Jubb (see https://arxiv.org/abs/2304.13356 for a survey). I will also mention recent joint work with Daan Janssen, Leon Loveridge, Kasia Rejzner, James Waldron (Comm. Math. Phys. 406:19 (2025) https://arxiv.org/abs/2403.11973)
10/12/25	Seminario	16:00	17:00	1201 Dal Passo	Paolo Palumbo	Università di Napoli Federico II	Operator Algebras Seminar An algebraic quantum information retrieval protocol for evaporating black holes using Tomita-Takesaki modular theory Abstract This thesis focuses on the operator-algebraic formulation of quantum field theory and the applications of Tomita-Takesaki modular theory in relativistic quantum information theory. I will provide a rigorous treatment of von Neumann algebras, emphasising their role in quantum field theory, and present the core theorem in the theory of von Neumann algebras: Tomita-Takesaki theorem. I will therefore illustrate its application in quantum field theory, with particular reference to entanglement entropy and thermality in field theory. Eventually, I present a relativistic generalization of the Hayden-Preskill protocol, following a recent paper by Verlinde and Heijden, and discuss its possible extensions in the type III (quantum field-theoretic) scenario.
09/12/25	Seminario	14:30	15:30	1201 Dal Passo	Chiara Bernardini	Università di Roma	Seminario di Equazioni Differenziali Serrin-type problems on ring-shaped domains: rigidity results Abstract We provide a characterization of rotationally symmetric solutions to the Serrin problem on ring-shaped domains in R^n (n ≥ 3). Our approach is based on a comparison-geometry argument. By exploiting a suitable conformal reformulation of our problem, we obtain sharp gradient estimates, which play a central role in establishing our main rigidity theorem. The comparison method can be effectively extended to deal with quasi- linear operators. This will be discussed in the second part of the talk, where we focus on the case of the p-Laplacian torsion problem. This talk is based on joint works with V. Agostiniani, S. Borghini, L. Mazzieri and A. Pinamonti. NB:This talk is part of the activity of the MUR Excellence Department Project MATH@TOV CUP E83C23000330006
05/12/25	Seminario	16:00	17:00		Chris MILIONIS	Affiliation	Algebra & Representation Theory Seminar (ARTS) "The center of the (semisimple) BMW algebras and an Okounkov-Vershik like approach to its finite dimensional representations" N.B.: this talk is part of the activity of the MIUR Excellence Department Project Mat-Mod@TOV (CUP E83C23000330006) Abstract   The BMW algebras <em>B</em><sub><em>n</em></sub>(<em>q</em>,<em>t</em>) are the <em>q</em>-analogues of the Brauer algebras and are in Schur-Weyl duality with quantum groups of types <em>B</em>, <em>C</em>, <em>D</em>. In the semisimple case, they fit in a multiplicity free chain of algebras and are equipped with a remarkable family of commuting elements, called the Jucys-Murphy (JM) elements. <br>   In this talk, we will determine the exact parameters <em>q</em>, <em>t</em> in <strong>C</strong> with <em>q</em> not a root of unity for which the centers of the BMW algebras are given as a subalgebra of the algebra of symmetric Laurent polynomials in the JM elements, called Wheel Laurent polynomials. As a corollary, we determine when the algebra generated by the JM elements is maximal commutative and in these cases, give an Okounkov-Vershik like approach to its finite dimensional representations. If time permits, we will talk about how one can get explicitly defined combinatorial formulas for a complete set of primitive idempotents in <em>B</em><sub><em>n</em></sub>(<em>q</em>,<em>t</em>) using this approach. <br>   <em><small> <strong><u>N.B.</u>:</strong> this talk is part of the activity of the MIUR Excellence Department Project MatMod@TOV (CUP E83C23000330006) </small></em>
05/12/25	Seminario	14:30	15:30	1201 Dal Passo	Valerio MELANI	Università di Firenze	Algebra & Representation Theory Seminar (ARTS) "Two-dimensional versions of the affine Grassmannians" N.B.: this talk is part of the activity of the MIUR Excellence Department Project Mat-Mod@TOV (CUP E83C23000330006) Abstract Let G be a complex affine algebraic group. If C is a smooth algebraic curve and x is a point in C, the affine Grassmannian is an algebro-geometric object that parametrizes G-bundles on C together with a trivialization outside x. Alternatively, one can define the affine Grassmannian as the quotient G((t))/G[[t]] . In this talk we present possible analogs for the affine Grassmannian, in the setting where the curve is replaced by a smooth projective surface, and the trivialization data are specified with respect to flags of closed subschemes. We also obtain parallel descriptions in terms of quotients of the double loop group G((t))((s)). Based on a joint work with A. Maffei and G. Vezzosi. N.B.: this talk is part of the activity of the MIUR Excellence Department Project MatMod@TOV (CUP E83C23000330006)
03/12/25	Seminario	16:00	17:00	1201 Dal Passo	Ian Charlesworth	Cardiff University, School of Mathematics	Operator Algebras Seminar Graph products, ε-independence, and atoms Note:This talk is part of the activity of the MUR Excellence Department Project MatMod@TOV (CUP E83C23000330006) Abstract In both classical and free probability theory, the central limit distribution can be modeled on a symmetric or free Fock space. The $q$-deformed Gaussians are the corresponding variables on a $q$-deformed Fock space (being the free semicirculars when $q = 0$ and the classical Gaussians when $q=1$), which raises the question of whether they arise from a central limit-type theorem. To find such a situation, Młotkowski introduced $varepsilon$-independence as an interpolation between free and classical independence, where distributions (or von Neumann algebras) are assigned to the vertices of a graph with adjacency matrix $varepsilon$, and are placed in a larger algebra in such a way that they are independent when they correspond to adjacent vertices and free otherwise. The corresponding product operation on von Neumann algebras corresponds to the idea of a graph product of groups, studied by Green. In this talk I will be interested in the following question: when do type I summands appear in the graph product of von Neumann algebras? The answer is pleasantly combinatorial, and can be described based on a family of polynomials built using the cliques in the graph (first arising in work of Cartier--Foata in 1969), and the behaviour of type I summands in the input algebras. This is joint work with David Jekel.