Found 2 result(s)

10.03.2009 (Tuesday)

Three recent results on asymptotics of oscillations

Regular Seminar Sir Michael Berry (Physics Department, University of Bristol)

15:00 City U.
room C343

The results are separate, and apparently paradoxical, and have implications for physics. First, when two exponentials compete, their interference can be dominated by the contribution with smaller exponent. Second, repeated differentiation of almost all functions in a wide class generates trigonometric oscillations ('almost all functions tend to cosx'). Third, it is possible to find band-limited functions that oscillate arbitrarily faster than their fastest Fourier component ('superoscillations').

16.12.2008 (Tuesday)

Tuck's incompressibility function: statistics for zeta zeros and eigenvalues

Regular Seminar Michael Berry (Bristol)

16:00 Brunel U.
room M128

Tuck devised a function Q(x), associated with a function D(x), whose positivity guarantees the absence of complex zeros of D(x) close to the real x axis, and observed that large values of Q are very rare if D is associated with the Riemann zeros. In an unusual and challenging application of random-matrix theory with P Shukla, this is explained by studying the probability distribution P(Q) for functions D with N zeros corresponding to eigenvalues of the Gaussian unitary ensemble (GUE).