Kavli Affiliate: Jinyi Shangguan | Summary:Balmer absorption lines are increasingly observed in the little red dots (LRDs) discovered by the James Webb Space Telescope, potentially tracing dense circumnuclear gas around rapidly accreting black holes. Motivated by this connection, we search for Balmer absorption using homogeneously analyzed spectra of a representative parent sample of 14,584 low-redshift […]

Kavli Affiliate: Jinyi Shangguan | Summary:We present a spectroscopic analysis of 14 little red dots (LRDs) at redshifts $2.2 < z < 6.7$ using NIRSpec/MSA prism and medium-resolution grating observations, aiming to constrain the nuclear gas structure through Balmer emission-line profiles, absorption features, relative line intensities, and continuum properties. We simultaneously decompose the broad, narrow, […]

Kavli Affiliate: Xian Chen| Summary: Knowledge distillation (KD) transfers a single scalar prediction from a large foundation model (FM) to compact vertical models (VMs), suffering from diminishing transfer ratio — the fraction of FM improvement captured by the VM — as a single scalar cannot convey the rich intermediate knowledge that larger FMs learn. To […]

Kavli Affiliate: Feng Long| Summary: We consider the problem of testing mutual independence among the components of a high-dimensional random vector. Building on the rank-based max-sum framework, we introduce fixed finite-$L_q$ power-sum statistics under three general classes of rank-based correlations: simple linear rank statistics, non-degenerate rank-based U-statistics and degenerate rank-based U-statistics. The proposed statistics interpolate […]

Kavli Affiliate: Feng Long| Summary: Low-rank adaptation (LoRA) has emerged as a powerful tool for parameter-efficient fine-tuning of large language models (LLMs). This paper studies LoRA under a federated learning setting, enabling collaborative fine-tuning across clients while preserving parameter efficiency. We focus on a highly heterogeneous regime in which clients share only partial structure and […]