LFCS Seminar: Thursday 2nd April: Xi Chen Thur, 02 Apr, 2.10pm Venue: IF G.03 Title: Adaptivity Does Not Help: Nearly Tight Lower Bounds for Boolean Monotonicity Testing Abstract Monotonicity testing asks: given a Boolean function f: {0,1}^n ->{0,1}, how many queries are needed to distinguish whether f is monotoneor far from monotone? For nonadaptive algorithms, the querycomplexity was pinned down at \sqrt{n}. Along the way, a series ofdirected isoperimetric inequalities were established to analyzetesters such as the edge tester and the path tester. But can adaptivity help beat the \sqrt{n} bound? In this talk we answerin the negative, by proving an almost tight n^{0.5-c} lower bound foradaptive monotonicity testing, for any constant c > 0. Our proof isbased on a multilevel extension of Talagrand's function. Joint work with Mark Chen, Hao Cui, William Pires and Jonah Stockwell(Columbia). Apr 02 2026 14.10 - 15.00 LFCS Seminar: Thursday 2nd April: Xi Chen Xi Chen, Columbia University https://www.engineering.columbia.edu/faculty-staff/directory/xi-chen Informatics Forum, G.03
LFCS Seminar: Thursday 2nd April: Xi Chen Thur, 02 Apr, 2.10pm Venue: IF G.03 Title: Adaptivity Does Not Help: Nearly Tight Lower Bounds for Boolean Monotonicity Testing Abstract Monotonicity testing asks: given a Boolean function f: {0,1}^n ->{0,1}, how many queries are needed to distinguish whether f is monotoneor far from monotone? For nonadaptive algorithms, the querycomplexity was pinned down at \sqrt{n}. Along the way, a series ofdirected isoperimetric inequalities were established to analyzetesters such as the edge tester and the path tester. But can adaptivity help beat the \sqrt{n} bound? In this talk we answerin the negative, by proving an almost tight n^{0.5-c} lower bound foradaptive monotonicity testing, for any constant c > 0. Our proof isbased on a multilevel extension of Talagrand's function. Joint work with Mark Chen, Hao Cui, William Pires and Jonah Stockwell(Columbia). Apr 02 2026 14.10 - 15.00 LFCS Seminar: Thursday 2nd April: Xi Chen Xi Chen, Columbia University https://www.engineering.columbia.edu/faculty-staff/directory/xi-chen Informatics Forum, G.03
Apr 02 2026 14.10 - 15.00 LFCS Seminar: Thursday 2nd April: Xi Chen Xi Chen, Columbia University https://www.engineering.columbia.edu/faculty-staff/directory/xi-chen