Shigefumi Mori, Kyoto University Institute of Advanced Study BIRATIONAL EQUIVALENCE OF ALGEBRAIC VARIETIES Lunedì 26 Novembre 2018, ore 16:30 Aula Chisini, Diparimento di Matematica, Via C. Saldini 50 | |
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Terence Tao, University of California, Los Angeles VAPORIZING AND FREEZING THE RIEMANN ZETA FUNCTION Venerdì 22 Giugno 2018, ore 14:30 Edificio U4, P.zza della Scienza, 4, Aula Luisella Sironi |
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Abstract
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In 1950, de Bruijn studied the effect of evolving the Riemann zeta function (or more precisely, a closely related function known as the Riemann xi function) by the (backwards) heat equation. His analysis, together with later work by Newman, showed that there existed a finite constant Lambda, at most 1/2 in value, such that the Riemann hypothesis for this evolved function was true at times greater than or equal to Lambda, and false below that threshold. Thus the Riemann hypothesis for the zeta function is equivalent to Lambda being non-positive. Recently, in joint work with Brad Rodgers, I was able to establish the complementary estimate that Lambda is non-negative, confirming a conjecture of Newman; thus, the Riemann hypothesis for zeta, if true, is only "barely so". The proof relies on an analysis of the dynamics of zeroes of entire functions under heat flow; it turns out that as one evolves forward in time, the zeroes "freeze" into approximate arithmetic progressions, while if one evolves backwards, the zeroes "vaporize" to leave the critical line. In followup work in an online collaborative "Polymath" project, the upper bound on Lambda has also been improved. We describe these results and their proofs in this talk.
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Zeljko Cuckovic, University of Toledo The essential norm estimates of Hankel and the $\overline\partial$-Neumann operators Venerdì 01 Giugno 2018, ore 11:00 Sala di Rappresentanza, Università di Milano, Via C. Saldini 50, Milano |
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Barry Simon, California Institute of Technology Tales of Our Forefathers Martedì 29 Maggio 2018, ore 11:00 Sala Consiglio, 7 piano, Edificio La Nave, Via Bonardi 9 |
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Barry Simon, California Institute of Technology SPECTRAL THEORY, SUM RULES AND LARGE DEVIATIONS Lunedì 28 Maggio 2018, ore 16:30 Aula Chisini, Diparimento di Matematica, Via C. Saldini 50 |
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Grigory Mikhalkin, Université de Genève Maximally writhed real algebraic knots and links Giovedì 17 Maggio 2018, ore 17:00 precise Sala di Rappresentanza, Università di Milano, Via C. Saldini 50, Milano |
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