activity
20222026
collaborators

18 papers

cs.AI2026

LEMON: Equivariant Learning over Attention Maps for Zero-Shot Misbehavior Monitoring on New LLMs

Guy Bar-Shalom, Mor Geva, Fabrizio Frasca +1

Large language models exhibit misbehaviors that hinder deployment in high-stakes settings. One approach to monitor such failures is to use an external LLM as a monitor, but this is…

astro-ph.SR2026

Nova shells in 3D: I. A catalog of integral field spectroscopic observations

Janis B. Rodríguez-González, Edgar Santamaría, Martin A. Guerrero +1

Classical novae eject material during thermonuclear eruptions on accreting white dwarfs, forming expanding shells whose structures and kinematics provide insights into the eruption…

cs.LG2026

Graph Metanetworks for Transformer Based Language Models

Yonathan Wolanowsky, Guy Bar-Shalom, Fabrizio Frasca +1

Weight-space learning treats the weights of neural networks as data, processed by other models called metanetworks. A key challenge is that different weights can realize the same f…

cs.LG2026

Permutation-Equivariant Flow Matching for Alignment-Free Neural Weight Generation

Arkadi Piven, Yam Eitan, Guy Bar-Shalom +5

A trained neural network can be represented by a parameter vector in high dimensions. Learning distributions over these vectors enables the generation of new models across various…

cs.CV2026

UniProbe: A Learnable Token-Level Hallucination Detector for Large VLMs using Multi-Structural Internal Representations

Dvir Samuel, Guy Bar-Shalom, Fabrizio Frasca +4

Large Vision-Language Models (LVLMs) achieve impressive visual reasoning and dialogue capabilities, yet frequently hallucinate content unsupported by the visual input. Effective mi…

cs.LG2026

A Graph Meta-Network for Learning on Kolmogorov-Arnold Networks

Guy Bar-Shalom, Ami Tavory, Itay Evron +3

Weight-space models learn directly from the parameters of neural networks, enabling tasks such as predicting their accuracy on new datasets. Naive methods -- like applying MLPs to…

cs.LG2025

On The Expressive Power of GNN Derivatives

Yam Eitan, Moshe Eliasof, Yoav Gelberg +3

Despite significant advances in Graph Neural Networks (GNNs), their limited expressivity remains a fundamental challenge. Research on GNN expressivity has produced many expressive…

cs.LG2025

Beyond Token Probes: Hallucination Detection via Activation Tensors with ACT-ViT

Guy Bar-Shalom, Fabrizio Frasca, Yaniv Galron +2

Detecting hallucinations in Large Language Model-generated text is crucial for their safe deployment. While probing classifiers show promise, they operate on isolated layer-token p…

cs.LG2025

Neural Message-Passing on Attention Graphs for Hallucination Detection

Fabrizio Frasca, Guy Bar-Shalom, Yftah Ziser +1

Large Language Models (LLMs) often generate incorrect or unsupported content, known as hallucinations. Existing detection methods rely on heuristics or simple models over isolated…

cs.LG2025

FS-KAN: Permutation Equivariant Kolmogorov-Arnold Networks via Function Sharing

Ran Elbaz, Guy Bar-Shalom, Yam Eitan +2

Permutation equivariant neural networks employing parameter-sharing schemes have emerged as powerful models for leveraging a wide range of data symmetries, significantly enhancing…

cs.LG2025

Beyond Next Token Probabilities: Learnable, Fast Detection of Hallucinations and Data Contamination on LLM Output Distributions

Guy Bar-Shalom, Fabrizio Frasca, Derek Lim +5

The automated detection of hallucinations and training data contamination is pivotal to the safe deployment of Large Language Models (LLMs). These tasks are particularly challengin…

cs.LG2025

Balancing Efficiency and Expressiveness: Subgraph GNNs with Walk-Based Centrality

Joshua Southern, Yam Eitan, Guy Bar-Shalom +3

Subgraph GNNs have emerged as promising architectures that overcome the expressiveness limitations of Graph Neural Networks (GNNs) by processing bags of subgraphs. Despite their co…

cs.LG2024

Topological Blindspots: Understanding and Extending Topological Deep Learning Through the Lens of Expressivity

Yam Eitan, Yoav Gelberg, Guy Bar-Shalom +3

Topological deep learning (TDL) is a rapidly growing field that seeks to leverage topological structure in data and facilitate learning from data supported on topological objects,…

cs.LG2024

A Flexible, Equivariant Framework for Subgraph GNNs via Graph Products and Graph Coarsening

Guy Bar-Shalom, Yam Eitan, Fabrizio Frasca +1

Subgraph GNNs enhance message-passing GNNs expressivity by representing graphs as sets of subgraphs, demonstrating impressive performance across various tasks. However, their scala…

cs.LG2024

Subgraphormer: Unifying Subgraph GNNs and Graph Transformers via Graph Products

Guy Bar-Shalom, Beatrice Bevilacqua, Haggai Maron

In the realm of Graph Neural Networks (GNNs), two exciting research directions have recently emerged: Subgraph GNNs and Graph Transformers. In this paper, we propose an architectur…

cs.CV2023

Weakly-supervised Representation Learning for Video Alignment and Analysis

Guy Bar-Shalom, George Leifman, Michael Elad +1

Many tasks in video analysis and understanding boil down to the need for frame-based feature learning, aiming to encapsulate the relevant visual content so as to enable simpler and…

cs.CV2022

Window-Based Distribution Shift Detection for Deep Neural Networks

Guy Bar-Shalom, Yonatan Geifman, Ran El-Yaniv

To deploy and operate deep neural models in production, the quality of their predictions, which might be contaminated benignly or manipulated maliciously by input distributional de…

cs.CV2022

TransBoost: Improving the Best ImageNet Performance using Deep Transduction

Omer Belhasin, Guy Bar-Shalom, Ran El-Yaniv

This paper deals with deep transductive learning, and proposes TransBoost as a procedure for fine-tuning any deep neural model to improve its performance on any (unlabeled) test se…