János Regöly-Mérei (1949–2009)

2 János Kollár

Presidents, Parties, and the Business Cycle, 19492009

Scattered works by political scientists since the 1970s have reported that Democratic presidents have compiled stronger economic records than their Republican counterparts: economic growth has been higher, unemployment lower, and inequality has fallen during Democratic administrations while the opposite outcomes have occurred under Republican presidents. Recently, however, Campbell has vigorous...

Real Face of János Bolyai Tamás Dénes

I n Vol. 56, No. 11, of Notices, I saw a fascinating article with the title: Changing Faces—The Mistaken Portrait of Legendre. The author, Peter Duren, writes with understandable bewilderment: “It seems incredible that such egregious error could have gone undetected for somany years.” This encouraged me to publish, in the same journal, the story—no less fascinating—of the real face of János Bol...

János Kollár and Sándor J Kovács

1. INTRODUCTION A recurring difficulty in the Minimal Model Program (MMP) is that while log terminal sin-gularities are quite well behaved (for instance, they are rational), log canonical singularities are much more complicated; they need not even be Cohen-Macaulay. The aim of this paper is to prove that, as conjectured in [Kol92, 1.13], log canonical singularities are Du Bois. The concept of D...

Colloquia Mathematica Societatis János Bolyai

1 . Our investigations might be suggested by a sort of optimalization problem which could be described vividly in practical terms as follows : suppose we are given a network of routes on which there are critical points endangered by fire. We want to place fire stations at an appropriate number of points from which any endangered point can be reached within a given time interval in case of emerg...