Recently
- Aug 2026
Spoke on Universality in alpha-cluster nuclei at EFB26 in Prague.
- Apr 2026
Invited talk, One Basis to Rule Them All, at the ECT* workshop on the fermion sign problem in Trento.
- 2026
FBCUBES starts — a four-year France–Brazil ANR project on universal behaviour in exotic nuclear systems, where I am co-PI and co-lead work package 3.
- 2025–26
On délégation at the CNRS.
- Nov 2024
Co-organised the INT program Quantum Few- and Many-Body Systems in Universal Regimes in Seattle.
What I work on
Universality near the unitary limit
Push the two-body scattering length far beyond the range of the interaction and few-body systems lose their memory of the microscopic detail. The famous consequence is the Efimov effect: three bosons develop an infinite tower of bound states, each one about 22.7 times wider than the one below it, repeating without end.
The theory I develop for this is a zero-shape theory, built on the S-matrix. In the non-relativistic framework a two-body problem is fixed by its S-matrix; keep the physical pole together with one more that sets the scale of the theory, and every shape parameter vanishes. A family of local potentials — the Bargmann potentials — realises that S-matrix exactly, so the theory and a potential calculation are the same thing.
Real systems are not at that idealised limit, and since 2008 most of my work has been about closing the gap — developing the theory of finite-range corrections that lets experimental and numerical data actually be confronted with universal predictions, and carrying it from three particles up to N bosons, as far as N = 6. Lately that has meant benchmarking the four-body problem against itself, and following the physics outward into hadronic correlations measured at the LHC.
Much of this only works because it is done with experimentalists. The clearest case is the 1S0 p–p scattering length: measured free of the Coulomb interaction by Aurora Tumino and her group, it becomes a number that universality has to account for, and the charge-symmetry test we published afterwards came straight out of that exchange. The same is true of correlation functions, where pΛ and ppΛ calculations meet what ALICE measures at the LHC, and of ultracold-gas experiments, which are where the tetramer limit cycle would be seen.
At the moment I am pushing it at alpha-cluster nuclei — 8Be, 12C, 16O and beyond. The universal Efimov function was built for bosons; alphas are weakly bound, they sit below threshold, and they carry charge. So the question is where the universal law breaks, and by how much: a two-body force alone reproduces 8Be but underbinds everything above it, which is what makes the three- and four-body terms interesting.
Neural networks as solvers
Since 2017 I have been using deep learning as a tool for quantum problems rather than as a subject of its own. Working with Paolo Recchia, we showed that gradient-based variational methods built on neural-network quantum states can come close to the exact solution of the few-body problem. That thread now carries into FBCUBES, where my task is to put neural networks inside a Faddeev–Yakubovsky solver and aim it at neutron-rich halo nuclei.
Before few-body physics
I came to this from elsewhere, and the detours still show. My thesis work was mathematical physics — the nonlinear Schrödinger equation solved quantum mechanically on the half-line, and before that an effective Lagrangian for black-hole horizon degrees of freedom. Then several years in nanoelectronics: transport and shot noise in quantum cellular automata, pair densities and Wigner crystallisation in quantum dots, the linear response of a strongly interacting one-dimensional Bose gas.
Selected papers
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Excited state of the α particle: A benchmark study
The first multi-group benchmark of the four-body problem: hyperspherical harmonics, Faddeev–Yakubovsky and effective-potential methods, all pointed at the excited state of 4He to see whether they agree. They do.
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pΛ and ppΛ correlation functions
Few-body theory applied to correlation functions in hadronic physics, where it can be compared against what ALICE measures at the LHC.
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Universal tetramer limit-cycle at the unitarity limit
With Tobias Frederico: the quantum tetramer has its own universal limit cycle at unitarity — the N = 4 rung of the Efimov ladder, and something ultracold-gas experiments could look for.
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Done with Aurora Tumino’s experimental group: they extract the 1S0 p–p scattering length free of Coulomb from the quasi-free p + d → p + p + n reaction, and we tie that number back to universality.
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Subleading contributions to N-boson systems inside the universal window
Subleading corrections for N-boson systems inside the universal window. The central result of Paolo Recchia’s thesis.
All publications 68
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2026
Advancing Machine Learning Applications in Quantum Few-Body Systems
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2025
pΛ and ppΛ correlation functions
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2025
Test of the Charge Symmetry Hypothesis of NN Interaction from the Coulomb-Free p-p Scattering Cross Section and Its Relation to Universality
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2025
Investigation of the charge symmetry of the nuclear interaction using quasi-free scattering.
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2025
Hyperradial energy density functional and effective interactions
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2025
Excited state of the α particle: A benchmark study
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2024
The three-nucleon interaction in pionful and pionless effective field theory
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2024
The ppp correlation function with a screened Coulomb potential
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2024
The Steepest Slope toward a Quantum Few-Body Solution: Gradient Variational Methods for the Quantum Few-body Problem
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2023
Universal tetramer limit-cycle at the unitarity limit
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2023
The Fate of excited state of 4He
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2023
From correlations to universal behavior in few-nucleon systems
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2023
Coulomb-free 1S0 p–p scattering length from the quasi-free p + d → p + p + n reaction and its relation to universality
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2022
Subleading contributions to N-boson systems inside the universal window
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2022
Gaussian Parametrization of Efimov Levels: Remnants of Discrete Scale Invariance
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2021
Many-body energy density functional
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2021
Efimov Physics and Connections to Nuclear Physics
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2020
Transfer learning for scalability of neural-network quantum states
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2020
Gaussian characterization of the unitary window for N=3: Bound, scattering, and virtual states
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2020
Finding Quantum Critical Points with Neural-Network Quantum States
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2020
Few bosons to many bosons inside the unitary window: A transition between universal and nonuniversal behavior
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2020
Effective Field Theory Descriptions of Few-Nucleon Systems
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2019
More on the Universal Equation for Efimov States
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2019
Embedding nuclear physics inside the unitary-limit window
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2018
1/2 spin-isospin fermions close to the unitary limit
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2017
Universal Behavior of Few-Boson Systems Using Potential Models
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2017
Implications of Efimov physics for the description of three and four nucleons in chiral effective field theory
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2016
Weakly bound states with spin-isospin symmetry
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2016
Matching universal behavior with potential models
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2016
Efimov physics with 1/2 spin-isospin fermions
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2015
Universal range corrections to Efimov trimers for a class of paths to the unitary limit
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2015
Enhancing quantum coherence with short-range correlated disorder
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2015
Efimov Physics with a Finite-Range Parameter
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2014
Universality in few-body Systems: from few-atoms to few-nucleons
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2014
Universality and scaling in the N-body sector of Efimov physics
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2014
Structure and Dynamics of Few-Helium Clusters using Soft-Core Potentials
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2014
Some aspects of universality in Efimov physics
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2014
N-boson spectrum from a discrete scale invariance
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2014
Efimov Spectrum in Bosonic Systems with Increasing Number of Particles
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2013
Universal nature and finite-range corrections in elastic atom-dimer scattering below the dimer breakup threshold
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2013
Six-Bodies Calculations Using the Hyperspherical Harmonics Method
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2013
Recombination rates from potential models close to the unitary limit
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2013
Efimov Physics in Small Bosonic Clusters
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2012
Energy spectra of small bosonic clusters having a large two-body scattering length
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2012
A new, analytic, non-perturbative, gauge-invariant formulation of "realistic" QCD
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2011
Suppression of Faraday waves in a Bose-Einstein condensate in the presence of an optical lattice
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2011
Spectra of helium clusters with up to six atoms using soft-core potentials
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2011
Nonsymmetrized hyperspherical harmonic basis for an A-body system
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2011
Nonsymmetrized Hyperspherical Harmonics Approach to A=6 System
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2011
Few-nucleon bound states using the unsymmetrized HH expansion
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2011
Exact solution for the degenerate ground-state manifold of a strongly interacting one-dimensional Bose-Fermi mixture
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2010
QCD and Effective Locality
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2009
The harmonic hyperspherical basis for identical particles without permutational symmetry
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2009
Non symmetrized basis function for identical particles
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2006
Momentum distribution in Parabolic Quantum Dots
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2006
Dynamic polarizability of 1D harmonically confined strongly interacting Bose gas
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2005
Ground-state densities and pair correlation functions in parabolic quantum dots
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2003
A QCA cell in silicon-on-insulator technology: theory and experiment
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2002
Simulation of time evolution of clocked and nonclocked quantum cellular automaton circuits
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2002
Enhancement and suppression of shot noise in capacitively coupled metallic double dots
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2001
Toward nanotechnology computer aided design: the NANOTCAD project
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2001
Shot noise enhancement and suppression in systems of coupled quantum dots
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2001
Proposed experiment to asses operation of quantum cellular automaton cells
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2001
Detection of Quantum Cellular Automaton Action in Silicon-on-insulator Cells
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2000
Design and simulation of an experiment for assessing the operation of QCA cells
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1999
The nonlinear Schr\"odinger equation on the half line
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1998
Quantization of the Nonlinear Schr\"odinger Equation on the Half Line
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1995
Effective Lagrangian for quantum black holes
Nothing matches that.
Students & collaborators
Doctoral supervision
- 2026–
A doctoral position opens with FBCUBES, on artificial intelligence and Faddeev–Yakubovsky methods for exotic nuclear systems. Recruitment is under way.
- 2019–22
Paolo Recchia — PhD, Université Côte d’Azur. Tackling quantum few-body problems with neural networks. I directed it fully; three papers grew out of it.
- 2017–22
Remmy Augusta Menzata Zen — PhD, National University of Singapore, co-directed with Stéphane Bressan. Data-driven modelling, simulation and optimisation with deep learning.
Master’s internships along the way: Arun Kumar Puthiavan (2018) and Constant Shouder (2014) on Efimov physics and clustering, and earlier, in the ultracold lattice group, Laurent de Forges de Parny (2008), Xavier Roy (2007), Florence Haudin (2006) and Aline Vernier (2005) — the last three each ended in a paper. Martha Wolak and Kean Loon Lee, both doctoral students at the Centre for Quantum Technologies in Singapore, spent extended stays with us in Nice between 2008 and 2011.
Thesis juries
- 2025
Referee for Alireza Dehghani’s thesis, Université Paris-Saclay — Reactions with antiprotons in the theory of cold nuclear collisions.
- 2021
Referee for Alexandre Pricoupenko’s thesis, Université Paris-Saclay — Beyond-mean-field effects in ultracold gases.
- 2019
Referee for Rimantas Lazauskas’s habilitation, Université de Strasbourg — Application of the complex scaling method to quantum scattering theory.
- 2015
Referee for Jakob Knorborg Pedersen’s thesis, Aarhus University — Classical and quantum behaviour of dipoles on a helix.
I work regularly with Alejandro Kievsky and Michele Viviani in Pisa, Arnoldas Deltuva in Lisbon, Eduardo Garrido in Madrid, and Tobias Frederico in Brazil, and on the experimental side with Aurora Tumino and the quasi-free scattering group. I referee for Physical Review A and C, Few-Body Systems, and others.
Teaching & service
I carry a full teaching load of 192 HETD a year in the Portail Sciences programmes, from L1 to M1. From 2014 to 2019 I coordinated the third semester of the L2 physics track, which meant timetables, the teaching team, and chairing the progression board.
I sat on the INPHYNI laboratory council from 2020 to 2024, and ran the Sophia-Antipolis library for ten years before that. From 2016 to 2020 I was an elected member of section 04 of the CoNRS, led the cold molecules and N-body effects theme of the GDR Atomes Froids, and was the French lead of the PHC Merlion project with Singapore.
Positions
- 2007–
Maître de conférences, Université Côte d’Azur — INLN, then INPHYNI. Promoted to hors classe.
- 2015
Habilitation à diriger des recherches, Nice — An exploration of the Efimov window.
- 2007
Marie Curie fellow, University of Liverpool.
- 2005–06
ATER, Université de Nice.
- 2002–06
Postdoc at the Scuola Normale Superiore, Pisa, with R. Colle and then M. P. Tosi.
- 1998–02
Contract researcher with M. Macucci, University of Pisa — nanoelectronics.
- 1996–99
Scientific associate, INFN Pisa.
- 1999
PhD, University of Pisa, with M. Mintchev — algebraic methods for field theories on a space with a boundary.
- 1995
Laurea in fisica, University of Pisa, with M. Maggiore — effective Lagrangian for black holes in quantum gravity.
Contact
Name.Surname at univ-cotedazur.fr
Institut de Physique de Nice — UMR 7010
Université Côte d’Azur et CNRS
17 rue Julien Lauprêtre, 06200 Nice, France