Tootfinder

Bridging Offline and Online Reinforcement Learning for LLMs
Jack Lanchantin, Angelica Chen, Janice Lan, Xian Li, Swarnadeep Saha, Tianlu Wang, Jing Xu, Ping Yu, Weizhe Yuan, Jason E Weston, Sainbayar Sukhbaatar, Ilia Kulikov
https://arxiv.org/abs/2506.21495 https://arxiv.org/pdf/2506.21495 https://arxiv.org/html/2506.21495
arXiv:2506.21495v1 Announce Type: new
Abstract: We investigate the effectiveness of reinforcement learning methods for finetuning large language models when transitioning from offline to semi-online to fully online regimes for both verifiable and non-verifiable tasks. Our experiments cover training on verifiable math as well as non-verifiable instruction following with a set of benchmark evaluations for both. Across these settings, we extensively compare online and semi-online Direct Preference Optimization and Group Reward Policy Optimization objectives, and surprisingly find similar performance and convergence between these variants, which all strongly outperform offline methods. We provide a detailed analysis of the training dynamics and hyperparameter selection strategies to achieve optimal results. Finally, we show that multi-tasking with verifiable and non-verifiable rewards jointly yields improved performance across both task types.
toXiv_bot_toot

Phase Evolution and Substrate-Dependent Nucleation of Quartz GeO$_2$ Films Grown by MOCVD on r- and c-Plane Sapphires
Botong Li, Imteaz Rahaman, Hunter Ellis, Bobby G. Duersch, Kathy Anderson, Kai Fu
https://arxiv.org/abs/2506.09380

Phase Evolution and Substrate-Dependent Nucleation of Quartz GeO$_2$ Films Grown by MOCVD on r- and c-Plane Sapphires
Ultrawide-bandgap (UWBG) semiconductors, such as GeO$_2$, are gaining significant attention for their potential in high-performance applications, particularly in piezoelectric devices. Despite extensive research, a comprehensive understanding of the growth dynamics and phase evolution of GeO$_2$ films via metal-organic chemical vapor deposition (MOCVD) remains insufficient. In this study, we investigate the growth behavior and morphological evolution of GeO$_2$ thin films on r-plane and c-plane…

Zigzag antiferromagnets in the SU(3) Hubbard model on the square lattice
Stijn V. Kleijweg, Philippe Corboz
https://arxiv.org/abs/2506.14703 https://

Zigzag antiferromagnets in the SU(3) Hubbard model on the square lattice
SU(N) Hubbard models exhibit a rich variety of phases, which may be realized through quantum simulation with ultracold atomic gases in optical lattices. In this work we study the Mott insulating phases of the SU(3) Hubbard model at 1/3-filling using infinite projected entangled-pair states, optimized with both imaginary time evolution and variational optimization. In the limit of strong interactions we reproduce the antiferromagnetic 3-sublattice ordered state previously identified in the SU(3)…

$^{50}$Cr and $^{53}$Cr neutron capture cross sections measurement at the n_TOF facility at CERN
P. P\'erez-Maroto, C. Guerrero, A. Casanovas, B. Fern\'andez, E. Mendoza, V. Alcayne, J. Lerendegui-Marco, C. Domingo-Pardo, J. M. Quesada, R. Capote, the n_TOF Collaboration
https://arxiv.org/abs/2506.17161

$^{50}$Cr and $^{53}$Cr neutron capture cross sections measurement at the n_TOF facility at CERN
$^{50,53}$Cr are very relevant in criticality safety benchmarks related to nuclear reactors. The discrepancies between the neutron capture cross section evaluations have an important effect on the $k_{eff}$ and $k_{\infty}$ in criticality benchmarks particularly sensitive to chromium. The $^{50,53}$Cr(n,$γ$) cross sections is to be determined between 1 and 100 keV with an 8-10% accuracy following the requirements of the NEA High Priority Request List (HPRL) to solve the current discrepancies. …

Violation of Luttinger's theorem in one-dimensional interacting fermions
Meng Gao, Yin Zhong
https://arxiv.org/abs/2506.04064 https://

Violation of Luttinger's theorem in one-dimensional interacting fermions
Using the density matrix renormalization group method, we systematically investigate the evolution of the Luttinger integral in the one-dimensional generalized t-V model as a function of filling and interaction strength, identifying three representative phases. In the weak-coupling regime, the zero-frequency Green's function shows a branch-cut structure at the Fermi momentum, and the Luttinger integral accurately reflects the particle density. As the interaction increases, the spectral weight n…