Joint hep-th seminars with ULB, VUB, KUL and UGent

When?
On 05 November 2025 at 10:30
Where?
Campus Plaine de Nimy - De Vinci - Salle Mirzakhani (Salle des conseils)

On the 5th of November UMONS will host the Belgian joint theoretical high-energy physics seminars organised by the Service de Physique de l’Univers, Champs et Gravitation of UMONS, the Service de Physique Théorique and the Service de Physique Théorique et Mathématique, both of the ULB, the Theoretical Particle Physics Group of the VUB, the High Energy Physics and Relativistic Field Theory group of the KUL, the Theoretical High Energy Physics group of the UGent and the International Solvay Institutes.

The seminars will take place in the Mirzakhani room of the building de Vinci and the speakers will be Dionysios Anninos (King’s College London), Kostas Siampos (Aristotle U., Thessaloniki) and Paolo Vallarino (VUB):

 

10h30: Dionysios Anninos

Features of the Partition Function of a Λ > 0 Universe

We discuss properties of the gravitational path integral for rhetorics of gravity with Lambda>0. We consider the problem in various spacetime dimensions, and for various matter fields. Time permitting, we also comment on the two-dimensional case.

 

12h00: Konstantinos Siampos

The geometric origin of the energy–momentum tensor improvement terms

In a flat background, the canonical energy momentum tensor of Lorentz and conformally invariant matter field theories can be improved to a symmetric and traceless tensor that gives the same conserved charges. We argue that the geometric origin of this improvement process is unveiled when the matter theory is coupled to Metric-Affine Gravity. In particular, we show that the Belinfante-Rosenfeld improvement terms correspond to the matter theory’s hypermomentum. The improvement terms in conformally invariant matter theories are also related to the hypermomentum however a general proof would require an extended investigation. We demonstrate our results through various examples, such as the free massless scalar, the Maxwell field, Abelian p-forms, the Dirac field and a non-unitary massless scalar field.

 

14h30: Paolo Vallarino

N = 2 Universality for integrated correlators at strong coupling

I will discuss recent developments in the study of integrated 4-point correlators of primary operators in a four-dimensional N= 2 superconformal field theory with SU(N) gauge group and matter in the fundamental and anti-symmetric representations on a squashed four-sphere. By employing matrix model techniques arising from supersymmetric localization, one can compute derivatives of the partition function with respect to the fundamental mass, the anti-symmetric mass and the squashing parameter. These derivatives correspond to integrated insertions of the N=2 flavour-current and stress-tensor multiplets, which are holographically dual to gluon and graviton scatterings in the presence of D7-branes. The main result that I will present is the emergence of a remarkable universality for the mixed gluon-graviton scattering amplitudes off D7-branes, obtained from the strong-coupling expansions of the integrated correlators. Indeed I will show that the leading and sub-leading large-N contributions in the strong-coupling regime are governed by universal asymptotic series of single ζ-values, which are also identical to those found for integrated giant-graviton correlators in N=4 SYM.

 

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