Research

Research Interest

• Generative AI

• Differential privacy

• High dimensional statistics

• Best subset selection

• Robust Inference

• Distributed learning

• Reinforcement learning

Working Preprints:

• Saptarshi Roy, Alessand Rinaldo, Purnamrita Sarkar (2026). Low-Dimensional Adaptation of Rectified Flow: A New Perspective through the Lens of Diffusion and Stochastic Localization.

Publications:

•  Vansh Bansal *, Saptarshi Roy *,  Purnamrita Sarkar, Alessandro Rinaldo (2025). On the convergence and straightness of Rectified Flow (Accepted in AISTATS 2026)

• Subha Maity, Saptarshi Roy, Songkai Xue, Mikhail Yurochkin, Yuekai Sun (2025). How does overparametrization affect performance on minority groups? (Accepted in Transactions on Machine Learning Research)

• Saptarshi Roy, Ambuj Tewari, Ziwei Zhu (2025). Understanding Best Subset Selection: A Tale of Two C(omplex)ities  (Accepted in Electronic Journal of Statistics)

• Sunrit Chakraborty *, Saptarshi Roy *, Debabrota Basu (2024). FLIPHAT: Joint Differential Privacy for High Dimensional Sparse Linear Bandits (Accepted at AISTATS 2025, To appear)  (* = Equal contribution)

• Saptarshi Roy,  Zehua Wang, Ambuj Tewari (2023). On the Computational Complexity of Private High-dimensional Model Selection via Exponential Mechanism (Accepted at Neurips 2024) 

• Ryan Swope , Amol Khanna , Philip Doldo , Saptarshi Roy , Edward Raff (2024).  Feature Selection from Differentially Private Correlations (Accepted at 17th ACM Workshop on Artificial Intelligence and Security)

• Saptarshi Roy, Ambuj Tewari, Ziwei Zhu (2024).  High-dimensional variable selection with heterogeneous signals: A precise asymptotic perspective (Accepted in Bernoulli) 

• Sunrit Chakraborty *, Saptarshi Roy *, Ambuj Tewari (2023). Thompson Sampling for High-Dimensional Sparse Linear Contextual Bandits (Accepted in ICML 2023) (* = Equal contribution)

• Saptarshi Roy, Kaustav Chakraborty, Somnath Bhadra, Ayanendranath Basu (2019).  Density Power Downweighting and Robust Inference: Some New Strategies (Accepted in Journal of Mathematics and Statistics)

Thesis:

•  Saptarshi Roy (2024). Statistics in the Modern Era: High Dimensions, Decision-Making, and Privacy