Denis BACH (1887–1946)

The Hardness of Computing an Eigenform Eric Bach and Denis Charles

The Fourier coefficients of modular forms encode very interesting arithmetic data. For example, divisor sums, partition numbers, trace of Frobenius of the reduction modulo primes of an elliptic curve over Q, and more generally, trace of Frobenius of many Galois representations of dimension 2 over finite fields (this being a conjecture of Serre) are all known to be, or conjectured to be, Fourier...

Denis Pelli

appeared, predator-prey interactions resulted in more selection pressure. Exceptionally preserved fossil occurrences reveal an increase in ecological complexity over time. Escalation in the number of different modes of life includes the exploitation of a greater range of levels above and below the sediment surface (tiering), as well as diversification of feeding mechanisms and modes of locomoti...

Bach in Mind

A conserved Bach current

The Bach tensor and a vector which generates conformal symmetries allow a conserved 4-current to be defined. The Bach 4-current gives rise to a quasilocal 2-surface expression for power per luminosity distance in the Vaidya exterior of collapsing fluid interiors. This is interpreted in terms of entropy generation. PACS numbers: 0420J, 0440N

John Denis Sargan 1924 — 1996

J. D. Sargan was born on August 23, 1924, in Doncaster, Yorkshire, where he spent his childhood. He was Emeritus Professor of Econometrics at the London School of Economics when he died at his home in Theydon Bois, Essex, on Saturday 13 April, 1996. He received his secondary education at Doncaster Grammar School and, at the age of 17, gained a State Scholarship for entrance to St. Johns College...