Publications

2026

• Molecular Scattering Distributions under New Boundary Conditions for the Boltzmann Equation
  
  • Kosuge Shingo
  • Aoki Kazuo
  • Giovangigli Vincent
  • Golse François
  , 2026. The scattering properties of kinetic boundary conditions for the Boltzmann equation recently proposed by Aoki et al. [see, e.g., Phys. Rev. E 106, 035306 (2022)] are investigated. Scattering patterns of reflected molecules are obtained for molecular-beam and Maxwellian incident distributions, and representative numerical results are presented.
• QUANTUM COHOMOLOGY AND IRRATIONALITY OF GUSHEL-MUKAI FOURFOLDS
  
  • Benedetti Vladimiro
  • Manivel Laurent
  • Perrin Nicolas
  , 2026. We compute the small quantum cohomology of Gushel-Mukai fourfolds. Following [13], our computations imply that the very general ones are not rational. Following [8], and thanks to a suitable deformation of the small quantum cohomology ring, we also deduce that a rational Gushel-Mukai fourfold has the same rational cohomology as some K3 surface.
• On the approximation of the von Neumann equation in the semiclassical limit. Part II : numerical analysis
  
  • Filbet Francis
  • Golse François
  , 2026. This paper is devoted to the numerical analysis of the Hermite spectral method proposed in [14], which provides, in the semiclassical limit, an asymptotic preserving approximation of the von Neumann equation. More precisely, it relies on the use of so-called Weyl's variables to effectively address the stiffness associated to the equation. Then by employing a truncated Hermite expansion of the density operator, we successfully manage this stiffness and provide error estimates by leveraging the propagation of regularity in the exact solution.
• A moment-based approach to the injective norm of random tensors
  
  • Dartois Stephane
  • Mckenna Benjamin
  , 2026. In this paper, we present a technically simple method to establish upper bounds on the expected injective norm of real and complex random tensors. Our approach is somewhat analogous to the moment method in random matrix theory, and is based on a deterministic upper bound on the injective norm of a tensor which might be of independent interest. Compared to previous approaches to these problems (spin-glass methods, epsilon-net techniques, Sudakov-Fernique arguments, and PAC-Bayesian proofs), our method has the benefit of being nonasymptotic, relatively elementary, and applicable to non-Gaussian models. We illustrate our approach on various models of random tensors, recovering some previously known (and conjecturally tight) bounds with simpler arguments, and presenting new bounds, some of which are provably tight. From the perspective of statistical physics, our results yield rigorous estimates on the ground-state energy of real and complex, possibly non-Gaussian, spin glass models. From the perspective of quantum information, they establish bounds on the geometric entanglement of random bosonic states and of random states with bounded multipartite Schmidt rank, both in the thermodynamic limits as well as the regimes of large local dimensions.
• The injective norm of CSS quantum error-correcting codes
  
  • Dartois Stephane
  • Zémor Gilles
  , 2025. In this paper, we compute the injective norm - a.k.a. geometric entanglement - of standard basis states of CSS quantum error-correcting codes. The injective norm of a quantum state is a measure of genuine multipartite entanglement. Computing this measure is generically NP-hard. However, it has been computed exactly in condensed-matter theory - notably in the context of topological phases - for the Kitaev code and its extensions, in works by Orús and collaborators. We extend these results to all CSS codes and thereby obtain the injective norm for a nontrivial, infinite family of quantum states. In doing so, we uncover an interesting connection to matroid theory and Edmonds' intersection theorem.
• Effect of polyelectrolyte mixing ratio and hydrophobic interactions on dynamics of (HM-)PDMAEMA/PEO-PMAA complexes
  
  • Chamchoum Matteo
  • Czakkel Orsolya
  • Prevost Sylvain
  • Seydel Tilo
  • Martin Nicolas
  • Azeri Özge
  • Kuzminskaya Olga
  • Dai Bin
  • Gradzielski Michael
  The Journal of Chemical Physics, American Institute of Physics, 2026, 164 (2). The complexation of oppositely charged polyelectrolytes leads to Polyelectrolyte Complexes (PECs). PECs can exist in many different states, depending on the architecture of the polymers and the environmental parameters of the solution. Using double hydrophilic block copolymers (DHBCs), PECs can be stabilized as dispersed aggregates in solutions. Specifically, the polymers involved in this investigation are a DHBC composed of a poly(ethylene glycol) block and a poly(methacrylic acid) block (PEO-PMAA) used as the polyanion and poly(2-(dimethylamino)ethyl methacrylate), with and without hydrophobic dodecyl substitutions, used as the polycation. In this paper, we discuss the behavior of the nanoscale dynamics with respect to their mixing ratio. We also test the impact of hydrophobic modifications on the dynamics of the aggregates. By neutron spin echo spectroscopy and neutron backscattering spectroscopy, we observed the role of electrostatic interaction as a friction induced on the polymers, where complexation leads to slower diffusion and the hydrophobic moieties affect the rigidity of the polymers. (10.1063/5.0285727)
  DOI : 10.1063/5.0285727
• Birational involutions of the real projective plane
  
  • Cheltsov Ivan
  • Mangolte Frédéric
  • Yasinsky Egor
  • Zimmermann Susanna
  Journal of the European Mathematical Society, European Mathematical Society, 2026, 28 (8), pp.3653-3711. We classify birational involutions of the real projective plane up to conjugation. In contrast with an analogous classification over the complex numbers (due to E. Bertini, G. Castelnuovo, F. Enriques, L. Bayle and A. Beauville), which includes 4 different classes of involutions, we discover 12 different classes over the reals, and provide many examples when the fixed curve of an involution does not determine its conjugacy class in the real plane Cremona group. (10.4171/JEMS/1537)
  DOI : 10.4171/JEMS/1537