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Gal Chechik

68 accepted papers

2026

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

AAAI 2026technical

The automated detection of hallucinations and training data contamination is pivotal to the safe deployment of Large Language Models (LLMs). These tasks are particularly challenging in settings where no access to model internals is available. Current approaches in this setup typically leverage only

Cited by 0SourcePDFScholar
2026

Expert Merging in Sparse Mixture of Experts with Nash Bargaining

ICLR 2026poster

Existing expert merging strategies for Sparse Mixture of Experts (SMoE) typically rely on input-dependent or input-independent averaging of expert parameters, but often lack a principled weighting mechanism. In this work, we reinterpret expert merging through the lens of game theory, revealing coope…

Cited by 0SourcecodeScholar
2026

Fast Autoregressive Video Diffusion and World Models with Temporal Cache Compression and Sparse Attention

ICML 2026poster

Autoregressive video diffusion models enable \emph{streaming} generation, opening the door to long-form synthesis, video world models, and interactive neural game engines. However, their core attention layers become a major bottleneck at inference time: as generation progresses, the KV cache grows, …

Cited by 0SourceScholar
2025

Adapting to the Unknown: Training-Free Audio-Visual Event Perception with Dynamic Thresholds

CVPR 2025poster

In the domain of audio-visual event perception, which focuses on the temporal localization and classification of events across distinct modalities (audio and visual), existing approaches are constrained by the vocabulary available in their training data. This limitation significantly impedes their c…

2025

Add-it: Training-Free Object Insertion in Images With Pretrained Diffusion Models

ICLR 2025poster

Adding Object into images based on text instructions is a challenging task in semantic image editing, requiring a balance between preserving the original scene and seamlessly integrating the new object in a fitting location. Despite extensive efforts, existing models often struggle with this balance…

Cited by 5SourcePDFScholar
2025

IT$^3$: Idempotent Test-Time Training

ICML 2025poster

Deep learning models often struggle when deployed in real-world settings due to distribution shifts between training and test data. While existing approaches like domain adaptation and test-time training (TTT) offer partial solutions, they typically require additional data or domain-specific auxilia…

Cited by 0SourcePDFScholar
2025

Knowing Before Saying: LLM Representations Encode Information About Chain-of-Thought Success Before Completion

ACL 2025finding

We investigate whether the success of a zero-shot Chain-of-Thought (CoT) process can be predicted before completion. Our classifier, based on LLM representations, performs well even before a single token is generated, suggesting that crucial information about the reasoning process is already present…

2025

Lightning-Fast Image Inversion and Editing for Text-to-Image Diffusion Models

ICLR 2025poster

Diffusion inversion is the problem of taking an image and a text prompt that describes it and finding a noise latent that would generate the exact same image. Most current deterministic inversion techniques operate by approximately solving an implicit equation and may converge slowly or yield poor…

2025

Make It Count: Text-to-Image Generation with an Accurate Number of Objects

CVPR 2025poster

Despite the unprecedented success of text-to-image diffusion models, controlling the number of depicted objects using text is surprisingly hard. This is important for various applications from technical documents, to children's books to illustrating cooking recipes. Generating object-correct counts…

Cited by 9SourcePDFScholar
2025

Padding Tone: A Mechanistic Analysis of Padding Tokens in T2I Models

NAACL 2025long

Text-to-image (T2I) diffusion models rely on encoded prompts to guide the image generation process. Typically, these prompts are extended to a fixed length by appending padding tokens to the input. Despite being a default practice, the influence of padding tokens on the image generation process has…

Cited by 1SourcePDFScholar
2025

RL-RC-DoT: A Block-level RL agent for Task-Aware Video Compression

CVPR 2025poster

Video encoders optimize compression for human perception by minimizing reconstruction error under bit-rate constraints. In many modern applications such as autonomous driving, an overwhelming majority of videos serve as input for AI systems performing tasks like object recognition or segmentation, r…

Cited by 0SourcePDFScholar
2025

TriTex: Learning Texture from a Single Mesh via Triplane Semantic Features

CVPR 2025poster

As 3D content creation continues to grow, transferring semantic textures between 3D meshes remains a significant challenge in computer graphics. While recent methods leverage text-to-image diffusion models for texturing, they often struggle to preserve the appearance of the source texture during tex…

Cited by 0SourcePDFScholar
2024

Bayesian Uncertainty for Gradient Aggregation in Multi-Task Learning

ICML 2024poster

As machine learning becomes more prominent there is a growing demand to perform several inference tasks in parallel. Multi-task learning (MTL) addresses this challenge by learning a single model that solves several tasks simultaneously and efficiently. Often optimizing MTL models entails first compu…

2024

Breathing Life Into Sketches Using Text-to-Video Priors

CVPR 2024highlight

A sketch is one of the most intuitive and versatile tools humans use to convey their ideas visually. An animated sketch opens another dimension to the expression of ideas and is widely used by designers for a variety of purposes. Animating sketches is a laborious process requiring extensive experien…

Cited by 29SourcePDFScholar
2024

Equivariant Deep Weight Space Alignment

ICML 2024poster

Permutation symmetries of deep networks make basic operations like model merging and similarity estimation challenging. In many cases, aligning the weights of the networks, i.e., finding optimal permutations between their weights, is necessary. Unfortunately, weight alignment is an NP-hard problem.…

2024

Generating Images of Rare Concepts Using Pre-trained Diffusion Models

AAAI 2024technical

Text-to-image diffusion models can synthesize high quality images, but they have various limitations. Here we highlight a common failure mode of these models, namely, generating uncommon concepts and structured concepts like hand palms. We show that their limitation is partly due to the long-tail na…

2024

Improved Generalization of Weight Space Networks via Augmentations

ICML 2024poster

Learning in deep weight spaces (DWS), where neural networks process the weights of other neural networks, is an emerging research direction, with applications to 2D and 3D neural fields (INRs, NeRFs), as well as making inferences about other types of neural networks. Unfortunately, weight space mode…

2024

LCM-Lookahead for Encoder-based Text-to-Image Personalization

ECCV 2024poster

"Recent advancements in diffusion models have introduced fast sampling methods that can effectively produce high-quality images in just one or a few denoising steps. Interestingly, when these are distilled from existing diffusion models, they often maintain alignment with the original model, retaini…

2024

Text2Model: Text-based Model Induction for Zero-shot Image Classification

EMNLP 2024finding

We address the challenge of building task-agnostic classifiers using only text descriptions, demonstrating a unified approach to image classification, 3D point cloud classification, and action recognition from scenes. Unlike approaches that learn a fixed representation of the output classes, we gene…

Cited by 0SourcePDFScholar
2024

Where's Waldo: Diffusion Features For Personalized Segmentation and Retrieval

NeurIPS 2024poster

Personalized retrieval and segmentation aim to locate specific instances within a dataset based on an input image and a short description of the reference instance. While supervised methods are effective, they require extensive labeled data for training. Recently, self-supervised foundation models h…

2023

An Image is Worth One Word: Personalizing Text-to-Image Generation using Textual Inversion

ICLR 2023top-25%

Text-to-image models offer unprecedented freedom to guide creation through natural language. Yet, it is unclear how such freedom can be exercised to generate images of specific unique concepts, modify their appearance, or compose them in new roles and novel scenes. In other words, we ask: how can we…

2023

Auxiliary Learning as an Asymmetric Bargaining Game

ICML 2023poster

Auxiliary learning is an effective method for enhancing the generalization capabilities of trained models, particularly when dealing with small datasets. However, this approach may present several difficulties: (i) optimizing multiple objectives can be more challenging, and (ii) how to balance the a…

2023

Equivariant Architectures for Learning in Deep Weight Spaces

ICML 2023oral

Designing machine learning architectures for processing neural networks in their raw weight matrix form is a newly introduced research direction. Unfortunately, the unique symmetry structure of deep weight spaces makes this design very challenging. If successful, such architectures would be capable…

2023

Example-based Hypernetworks for Multi-source Adaptation to Unseen Domains

EMNLP 2023long findings

As Natural Language Processing (NLP) algorithms continually achieve new milestones, out-of-distribution generalization remains a significant challenge. This paper addresses the issue of multi-source adaptation for unfamiliar domains: We leverage labeled data from multiple source domains to generaliz…

Cited by 0SourceScholar
2023

Graph Positional Encoding via Random Feature Propagation

ICML 2023poster

Two main families of node feature augmentation schemes have been explored for enhancing GNNs: random features and spectral positional encoding. Surprisingly, however, there is still no clear understanding of the relation between these two augmentation schemes. Here we propose a novel family of posit…

Cited by 22SourcePDFScholar
2023

Learning to Initiate and Reason in Event-Driven Cascading Processes

ICML 2023poster

Training agents to control a dynamic environment is a fundamental task in AI. In many environments, the dynamics can be summarized by a small set of events that capture the semantic behavior of the system. Typically, these events form chains or cascades. We often wish to change the system behavior u…

Cited by 0SourcePDFScholar
2023

Linguistic Binding in Diffusion Models: Enhancing Attribute Correspondence through Attention Map Alignment

NeurIPS 2023oral

Text-conditioned image generation models often generate incorrect associations between entities and their visual attributes. This reflects an impaired mapping between linguistic binding of entities and modifiers in the prompt and visual binding of the corresponding elements in the generated image. A…

2023

Norm-guided latent space exploration for text-to-image generation

NeurIPS 2023poster

Text-to-image diffusion models show great potential in synthesizing a large variety of concepts in new compositions and scenarios. However, the latent space of initial seeds is still not well understood and its structure was shown to impact the generation of various concepts. Specifically, simple op…

2023

Planning and Learning with Adaptive Lookahead

AAAI 2023technical

Some of the most powerful reinforcement learning frameworks use planning for action selection. Interestingly, their planning horizon is either fixed or determined arbitrarily by the state visitation history. Here, we expand beyond the naive fixed horizon and propose a theoretically justified strateg…

Cited by 9SourcePDFScholar
2023

Point Cloud Completion with Pretrained Text-to-Image Diffusion Models

NeurIPS 2023poster

Point cloud data collected in real-world applications are often incomplete. This is because they are observed from partial viewpoints, which capture only a specific perspective or angle, or due to occlusion and low resolution. Existing completion approaches rely on datasets of specific predefined ob…

2023

Train Hard, Fight Easy: Robust Meta Reinforcement Learning

NeurIPS 2023poster

A major challenge of reinforcement learning (RL) in real-world applications is the variation between environments, tasks or clients. Meta-RL (MRL) addresses this issue by learning a meta-policy that adapts to new tasks. Standard MRL methods optimize the average return over tasks, but often suffer fr…

Cited by 13SourcePDFScholar
2022

"“This Is My Unicorn, Fluffy”: Personalizing Frozen Vision-Language Representations"

ECCV 2022poster

"Large Vision & Language models pretrained on web-scale data provide representations that are invaluable for numerous V&L problems. However, it is unclear how they can be extended to reason about user-specific visual concepts in unstructured language. This problem arises in multiple domains, from pe…

Cited by 94SourcePDFScholar
2022

DETReg: Unsupervised Pretraining With Region Priors for Object Detection

CVPR 2022poster

Recent self-supervised pretraining methods for object detection largely focus on pretraining the backbone of the object detector, neglecting key parts of detection architecture. Instead, we introduce DETReg, a new self-supervised method that pretrains the entire object detection network, including t…

Cited by 157PDFcodeScholar
2022

Multi-Task Learning as a Bargaining Game

ICML 2022spotlight

In Multi-task learning (MTL), a joint model is trained to simultaneously make predictions for several tasks. Joint training reduces computation costs and improves data efficiency; however, since the gradients of these different tasks may conflict, training a joint model for MTL often yields lower pe…

2022

Object-Region Video Transformers

CVPR 2022poster

Recently, video transformers have shown great success in video understanding, exceeding CNN performance; yet existing video transformer models do not explicitly model objects, although objects can be essential for recognizing actions. In this work, we present Object-Region Video Transformers (ORViT)…

Cited by 105PDFScholar
2022

On Covariate Shift of Latent Confounders in Imitation and Reinforcement Learning

ICLR 2022poster

We consider the problem of using expert data with unobserved confounders for imitation and reinforcement learning. We begin by defining the problem of learning from confounded expert data in a contextual MDP setup. We analyze the limitations of learning from such data with and without external rewar…

Cited by 19SourcePDFScholar
2022

Optimizing Tensor Network Contraction Using Reinforcement Learning

ICML 2022spotlight

Quantum Computing (QC) stands to revolutionize computing, but is currently still limited. To develop and test quantum algorithms today, quantum circuits are often simulated on classical computers. Simulating a complex quantum circuit requires computing the contraction of a large network of tensors.…

Cited by 18SourcePDFScholar
2022

Reinforcement Learning with a Terminator

NeurIPS 2022accept

We present the problem of reinforcement learning with exogenous termination. We define the Termination Markov Decision Process (TerMDP), an extension of the MDP framework, in which episodes may be interrupted by an external non-Markovian observer. This formulation accounts for numerous real-world si…

2021

ACAV100M: Automatic Curation of Large-Scale Datasets for Audio-Visual Video Representation Learning

ICCV 2021poster

The natural association between visual observations and their corresponding sound provides powerful self-supervisory signals for learning video representations, which makes the ever-growing amount of online videos an attractive source of training data. However, large portions of online videos contai…

Cited by 55PDFScholar
2021

Auxiliary Learning by Implicit Differentiation

ICLR 2021poster

Training neural networks with auxiliary tasks is a common practice for improving the performance on a main task of interest. Two main challenges arise in this multi-task learning setting: (i) designing useful auxiliary tasks; and (ii) combining auxiliary tasks into a single coherent loss. Here, we p…

2021

Compositional Video Synthesis with Action Graphs

ICML 2021spotlight

Videos of actions are complex signals containing rich compositional structure in space and time. Current video generation methods lack the ability to condition the generation on multiple coordinated and potentially simultaneous timed actions. To address this challenge, we propose to represent the ac…

2021

Controlling Graph Dynamics with Reinforcement Learning and Graph Neural Networks

ICML 2021spotlight

We consider the problem of controlling a partially-observed dynamic process on a graph by a limited number of interventions. This problem naturally arises in contexts such as scheduling virus tests to curb an epidemic; targeted marketing in order to promote a product; and manually inspecting posts t…

Cited by 67SourcePDFScholar
2021

From Local Structures to Size Generalization in Graph Neural Networks

ICML 2021spotlight

Graph neural networks (GNNs) can process graphs of different sizes, but their ability to generalize across sizes, specifically from small to large graphs, is still not well understood. In this paper, we identify an important type of data where generalization from small to large graphs is challenging…

Cited by 161SourcePDFScholar
2021

GP-Tree: A Gaussian Process Classifier for Few-Shot Incremental Learning

ICML 2021spotlight

Gaussian processes (GPs) are non-parametric, flexible, models that work well in many tasks. Combining GPs with deep learning methods via deep kernel learning (DKL) is especially compelling due to the strong representational power induced by the network. However, inference in GPs, whether with or wit…

2021

Improve Agents without Retraining: Parallel Tree Search with Off-Policy Correction

NeurIPS 2021poster

Tree Search (TS) is crucial to some of the most influential successes in reinforcement learning. Here, we tackle two major challenges with TS that limit its usability: \textit{distribution shift} and \textit{scalability}. We first discover and analyze a counter-intuitive phenomenon: action selection…

2021

Personalized Federated Learning With Gaussian Processes

NeurIPS 2021poster

Federated learning aims to learn a global model that performs well on client devices with limited cross-client communication. Personalized federated learning (PFL) further extends this setup to handle data heterogeneity between clients by learning personalized models. A key challenge in this setting…

2021

Personalized Federated Learning using Hypernetworks

ICML 2021spotlight

Personalized federated learning is tasked with training machine learning models for multiple clients, each with its own data distribution. The goal is to train personalized models collaboratively while accounting for data disparities across clients and reducing communication costs. We propose a nove…

2020

A causal view of compositional zero-shot recognition

NeurIPS 2020spotlight

People easily recognize new visual categories that are new combinations of known components. This compositional generalization capacity is critical for learning in real-world domains like vision and language because the long tail of new combinations dominates the distribution. Unfortunately, learnin…

2020

Contrastive Learning for Weakly Supervised Phrase Grounding

ECCV 2020poster

Phrase grounding, the problem of associating image regions to caption words, is a crucial component of vision-language tasks. We show that phrase grounding can be learned by optimizing word-region attention to maximize a lower bound on mutual information between images and caption words. Given pairs…

2020

Learning Canonical Representations for Scene Graph to Image Generation

ECCV 2020poster

Generating realistic images of complex visual scenes becomes challenging when one wishes to control the structure of the generated images. Previous approaches showed that scenes with few entities can be controlled using scene graphs, but this approach struggles as the complexity of the graph (the nu…

2019

Network Adaptation Strategies for Learning New Classes without Forgetting the Original Ones

ICASSP 2019accepted

We address the problem of adding new classes to an existing classifier without hurting the original classes, when no access is allowed to any sample from the original classes. This problem arises frequently since models are often shared without their training data, due to privacy and data ownership…

Cited by 0SourceScholar
2018

Mapping Images to Scene Graphs with Permutation-Invariant Structured Prediction

NeurIPS 2018poster

Machine understanding of complex images is a key goal of artificial intelligence. One challenge underlying this task is that visual scenes contain multiple inter-related objects, and that global context plays an important role in interpreting the scene. A natural modeling framework for capturing suc…

2017

Context-Aware Captions From Context-Agnostic Supervision

CVPR 2017spotlight

We introduce an inference technique to produce discriminative context-aware image captions (captions that describe differences between images or visual concepts) using only generic context-agnostic training data (captions that describe a concept or an image in isolation). For example, given images a…

Cited by 174PDFcodeScholar
2017

Learning From Noisy Large-Scale Datasets With Minimal Supervision

CVPR 2017spotlight

We present an approach to effectively use millions of images with noisy annotations in conjunction with a small subset of cleanly-annotated images to learn powerful image representations. One common approach to combine clean and noisy data is to first pre-train a network using the large noisy datase…

Cited by 606PDFScholar