Finite-density lattice QCD and sign problem: current status and open problems

hep-th 2026-06 unverdicted novelty 8.0 of 10

The Pfaffian phase in BFSS becomes an O(9) pseudoscalar operator in a bosonic matrix integral, requiring 10-loop order in the high-T expansion before the sign problem is detectable in the 't Hooft regime.

hep-lat 2026-08 conditional novelty 6.0 of 10

The paper proposes a reweighting framework that evaluates the fermion determinant ratio in the continuum via worldline methods and uses it to reweight background-free lattice QED ensembles for vacuum polarization in a...

hep-lat 2026-08 conditional novelty 6.0 of 10

Using lattice-derived Lee-Yang zeros and chiral universality, this paper reconstructs the QCD crossover curvature kappa2 = 0.012(+0.002,-0.004), consistent with prior lattice results, without inputting the curvature itself.

quant-ph 2026-04 unverdicted novelty 6.0 of 10

The paper derives explicit finite-d break-even synthesis costs for qudit vs. qubit encodings of diagonal quadratic operators in product-formula and LCU simulations, identifying low-d regions where qudits yield savings.

hep-ph 2025-09 conditional novelty 6.0 of 10

An RBF neural-network expansion of the interaction factor turns Euclidean path integrals into factorized Gaussian integrals that reproduce the 1+1 phi^4 phase transition line in seconds.

hep-ph 2025-09 conditional novelty 6.0 of 10

NLO chiral perturbation theory for non-degenerate two-flavor real and pseudoreal gauge theories is derived, fitted to Sp(4) lattice data, and applied to pion dark matter self-interactions.

hep-th 2025-09 conditional novelty 6.0 of 10

In the Veneziano large-N_c limit, QCD at finite baryon chemical potential has two partially deconfined phases (PD-1, PD-2) and two confined phases (CC-1, CC-2), separated by a Gross-Witten-Wadia transition that can be...

hep-ph 2025-08 conditional novelty 6.0 of 10

In dense QCD, the most attractive quark pairing channel is classified by helicity amplitudes and renormalization group equations, with a new p-wave (1P1) channel favored for symmetric flavor and attraction found in th...

quant-ph 2025-05 conditional novelty 6.0 of 10

On a trapped-ion quantum computer, the authors prepared multiple meson wave packets and simulated their early-time collisions in a 1+1D Z2 lattice gauge theory.

astro-ph.HE 2024-12 conditional novelty 6.0 of 10

Using full general relativity, the authors compute f-mode oscillation frequencies for neutron stars with hyperons, delta baryons, and quark-matter cores, and find composition-dependent shifts in universal asteroseismo...

hep-ph 2024-11 conditional novelty 6.0 of 10

Using approximate renormalization group methods, the authors map phase diagrams of Z3 spin and gauge models and find that only chiral spin models and their duals show an infinite Devil's flower family of inhomogeneous...

astro-ph.HE 2026-08 conditional novelty 5.0 of 10

A Bayesian analysis of smooth hadron-quark crossover neutron stars using NICER and GW170817 data favors a broad, high-density mixed transition, disfavors pure quark cores, and makes a neutron-star interpretation of GW...

hep-lat 2026-07 conditional novelty 5.0 of 10

Path optimization improves the average phase factor in the Stephanov model at high chemical potential but not at low chemical potential or in the chiral random matrix model, pointing to the global sign problem as the ...

hep-lat 2025-02 conditional novelty 5.0 of 10

Path optimization with machine learning reproduces analytic results in the 1D lattice Thirring model, and dropping the Jacobian from the learning step still works.

hep-lat 2024-12 conditional novelty 4.0 of 10

On a finer lattice than previous studies, the speed of sound in dense two-color QCD again rises above the conformal bound near the superfluid transition.

hep-lat 2024-12 conditional novelty 2.0 of 10

Proceedings summarizing lattice QC2D results: the conformal bound c_s^2/c^2 = 1/3 is exceeded in the BCS phase at T = 40 and 80 MeV, with a rich hadronic/BEC/BCS phase structure.