collaborators

8 papers

cs.IR2026

ADORE: Iterative Query Expansion with Retrieval-Grounded Relevance Feedback

Amin Bigdeli, Negar Arabzadeh, Radin Hamidi Rad +3

LLM-based query expansion improves retrieval by enriching the original query with additional context. Yet most methods remain generation-driven, producing plausible pseudo-document…

cs.IR2026

Led to Mislead: Adversarial Content Injection for Attacks on Neural Ranking Models

Amin Bigdeli, Amir Khosrojerdi, Radin Hamidi Rad +3

Neural Ranking Models (NRMs) are central to modern information retrieval but remain highly vulnerable to adversarial manipulation. Existing attacks often rely on heuristics or surr…

cs.IR2026

A Reproducibility Study of LLM-Based Query Reformulation

Amin Bigdeli, Radin Hamidi Rad, Hai Son Le +4

Large Language Models (LLMs) are now widely used for query reformulation and expansion in Information Retrieval, with many studies reporting substantial effectiveness gains. Howeve…

cs.IR2026

ReFormeR: Learning and Applying Explicit Query Reformulation Patterns

Amin Bigdeli, Mert Incesu, Negar Arabzadeh +2

We present ReFormeR, a pattern-guided approach for query reformulation. Instead of prompting a language model to generate reformulations of a query directly, ReFormeR first elicits…

cs.IR2025

QueryGym: A Toolkit for Reproducible LLM-Based Query Reformulation

Amin Bigdeli, Radin Hamidi Rad, Mert Incesu +3

We present QueryGym, a lightweight, extensible Python toolkit that supports large language model (LLM)-based query reformulation. This is an important tool development since recent…

cs.IR2025

Evaluating the Robustness of Retrieval-Augmented Generation to Adversarial Evidence in the Health Domain

Shakiba Amirshahi, Amin Bigdeli, Charles L. A. Clarke +1

Retrieval augmented generation (RAG) systems provide a method for factually grounding the responses of a Large Language Model (LLM) by providing retrieved evidence, or context, as…