BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20260601T092026EDT-3297md9ZwB@132.216.98.100 DTSTAMP:20260601T132026Z DESCRIPTION:\n \n \n \n TITLE / TITRE\n Robust and Tuning-Free Sparse Linear Reg ression via Square-Root Slope\n \n ABSTRACT / RÉSUMÉ \n\n We consider the hig h-dimensional linear regression model and assume that a fraction of the re sponses are contaminated by an adversary with complete knowledge of the da ta and the underlying distribution. We are interested in the situation whe n the dense additive noise can be heavy-tailed but the predictors have sub -Gaussian distribution. We establish minimax lower bounds that depend on t he fraction of the contaminated data and the tails of the additive noise. Moreover\, we design a modification of the square root Slope estimator wit h several desirable features: (a) it is provably robust to adversarial con tamination\, with the performance guarantees that take the form of sub-Gau ssian deviation inequalities and match the lower error bounds up to log-fa ctors\; (b) it is fully adaptive with respect to the unknown sparsity leve l and the variance of the noise\, and (c) it is computationally tractable as a solution of a convex optimization problem. To analyze the performance of the proposed estimator\, we prove several properties of matrices with sub-Gaussian rows that could be of independent interest. This is joint wor k with Stanislav Minsker and Lang Wang.\n\n \n Speaker\n \n\n Mohamed Ndaoud i s an Assistant Professor (tenure track) of Statistics at ESSEC Business Sc hool\, and a member of the Statistics Department of CREST. He received a P hD in theoretical statistics\, under the supervision of A.B. Tsybakov. His research interests are in high dimensional statistics. In particular\, he is interested in variable selection\, community detection and robust stat istics in the high dimensional setting.\n\n Website: https://sites.google.c om/view/mndaoud/home\n\n  \n\n  \n \n \n \n\n DTSTART:20231117T203000Z DTEND:20231117T213000Z LOCATION:Room 1104\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Mohamed Ndaoud (ESSEC Business School) URL:/mathstat/channels/event/mohamed-ndaoud-essec-busi ness-school-352701 END:VEVENT END:VCALENDAR