arXiv AI

Internal Discrepancy for Contrastive Learning: Generalization Bounds and Downstream Behaviors

The paper introduces the concept of internal discrepancy, measuring the gap between the mean representation of positive samples and latent cluster centers in contrastive learning. It derives a generalization bound for downstream supervised tasks that depends on this discrepancy, providing a unifying framework for existing assumptions and motivating a relaxed k‑means loss to reduce it. The study also explores how contrastive learning affects downstream behavior, particularly in class‑imbalanced settings, and establishes properties of the resulting supervised losses.

arXiv Machine Learning
Jun 16

InfoNCE Induces Gaussian Distribution

arXiv:2602. 24012v2 Announce Type: replace Abstract: Contrastive learning has become a cornerstone of modern representation learning, allowing training with massive unlabeled data for both task-specific and general (foundation) models.

By Roy Betser, Eyal Gofer, Meir Yossef Levi, Guy Gilboa
arXiv AI
Oct 26

Rethinking Representation Geometry in Supervised Contrastive Learning under Long-Tailed Data

The paper investigates whether supervised contrastive learning objectives produce a regular simplex geometry in representation space when trained on long‑tailed data. It shows that existing objectives fail to achieve this geometry because they depend on class sample counts. The authors propose a fully balanced contrastive objective that provably forms a regular simplex, leading to a more balanced representation space and improved performance on long‑tailed recognition and transfer learning tasks.

By Joonhyeok Jeong, Jy-yong Sohn, Kibok Lee
arXiv AI
Sep 2

When Features Become Instances: Inverted Contrastive Learning for Unsupervised Feature Selection

The paper introduces Inverted Contrastive Learning for Unsupervised Feature Selection (ICLFS), a method that treats each feature as a sample by inverting the data matrix and applies a contrastive learning framework to learn consistent representations across masked positive views and a shuffled negative view. Feature saliency is derived from the magnitude of projector‑space embeddings, and a Laplacian‑Gated Ranking Correction step refines the ranking by reducing local redundancy. Experiments on 12 benchmark datasets show that ICLFS achieves the best clustering accuracy on 10 datasets compared to both classical and neural baselines, demonstrating the effectiveness of feature‑wise contrastive consistency for unsupervised feature selection.

By Utsab Ghosh, Roshni Chakraborty