The Sign Problem of Fermions: Computational Challenges and Emerging Approaches

Contribution List

1. Registration

4/20/26, 8:45 AM

3. Welcome ECT* Director and organizers

4/20/26, 9:15 AM

4. Wick’s Route to Fermionic and Quantum Spin Simulations

Riccardo Rossi

4/20/26, 9:45 AM

5. The Challenge of Working with Divergent Series

Boris Svistunov

4/20/26, 11:00 AM

6. Cluster algorithms, a strategy to lower the scaling of the variance

Roland Assaraf

4/20/26, 12:00 PM

7. The notorious past of the sign problem

David Ceperley

4/20/26, 2:15 PM

8. Imaginary-Time Path-Integral Perspective on Warm Dense Matter: From Theory to Experiment

Maximilian Boehme

4/20/26, 3:15 PM

10. Accelerated free energy estimation and reweighting estimators for density response in ab initio path integral Monte Carlo

Pontus Svensson

4/20/26, 4:30 PM

11. The nature of the sign problem in the FCIQMC method: some numerical results based on the Hubbard model

Ali Alavi

4/21/26, 9:00 AM

12. On the accuracy of diffusion Monte Carlo-based estimates of interaction energies

Andrea Zen

4/21/26, 9:45 AM

13. Fermion Sign Problem from the Perspective of Lee-Yang Phase Transition Theory

Xinzheng Li

4/21/26, 11:00 AM

14. New Methods for Overcoming the Fermion Sign Problem

Yunuo Xiong

4/21/26, 11:45 AM

34. Complex phase diagram

Qi-Jun Ye

4/21/26, 2:15 PM

15. One Basis to Rule Them All Bosons and Fermions from Unsymmetrized Hyperspherical Harmonics

Mario Gattobigio

4/21/26, 3:00 PM

17. Physics-informed Neural Networks and quantum mechanical many-body problems: applications to quantum dot systems

Morten Hjorth-Jensen

4/21/26, 4:15 PM

18. Sign problems and sign blessings in quantum simulations

Alessandro Roggero

4/21/26, 5:00 PM

19. Advancing time-dependent density functional theory for applications at elevated pressure and temperature conditions

Zhandos Moldabekov

4/22/26, 9:00 AM

20. A deep dive into ab initio path integral Monte Carlo simulations of warm dense matter using fictitious identical particles

Tobias Dornheim

4/22/26, 9:45 AM

21. Lattice Regularized Diffusion Monte Carlo: an effective way to deal with the Fermionic sign problem

Michele Casula

4/22/26, 11:15 AM

I will review the Lattice Regularized Diffusion Monte Carlo (LRDMC) algorithm and show how it can be effectively used to deal with the Fermionic sign problem. The LRDMC allows one to simulate an effective Hamiltonian that can be tailored to cross the nodal surface in a controlled way with an adjustable parameter. Extrapolating the energies as a function of this parameter seems to be a...

22. Hydrodynamic Backflow for Easing the Fermion Sign in Finite-Temperature Electron Path Integral Simulations

Ingvars Vitenburgs

4/22/26, 12:00 PM

23. Guided tour in Trento’s city center

4/22/26, 4:30 PM

24. One-particle spectral function of the warm dense electrons from Path-integral Monte Carlo simulations

Paul Hamann

4/23/26, 9:00 AM

26. Learning the Fermion sign structure in path-integral Monte Carlo

Jarvist Moore Frost

4/23/26, 9:45 AM

27. Approximating Many-Electron Wave Functions using Deep Neural Networks

Matthew Foulkes

4/23/26, 11:00 AM

28. Speeding up PIMD and PIMC Simulations of Indistinguishable Particles

Barak Hirshberg

4/23/26, 2:00 PM

29. Fermionic trial wave functions for extended systems

Markus Holzmann

4/23/26, 2:45 PM

30. Hamiltonian Monte Carlo enhanced by Exact Diagonalization

Johann Ostmeyer

4/23/26, 4:00 PM

35. Aperitivo and free discussion

4/23/26, 4:45 PM

32. Interplay of Gauss Law and the Fermion Sign Problem in Quantum Link Models with Dynamical Matter

Emilie Huffman

4/24/26, 9:45 AM

31. New opportunities in quantum simulation with Rydberg atoms

Lode Pollet

4/24/26, 11:00 AM

16. Talk Pederiva

Francesco Pederiva

9. Talk Tolias

Panagiotis Tolias

2. Welcome