ANNALES
DE LA FACULTÉ
DES SCIENCES
DE TOULOUSE
Mathématiques

JOSEPH TAPIA,
ALEXEI SKOROBOGATOV AND ALEXANDRE VARCHENKO

Preface

Tome XXV, n° 2-3 (2016), p. i-i.

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© Université Paul Sabatier, Toulouse, 2016, tous droits réservés.

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Preface

This volume is a collection of papers in honour of Vadim Schechtman's
60th anniversary. The diverse fields of mathematics where the papers belong
exemplify Vadik's broad vision of our beautiful subject. The list of areas to
which he has contributed reads almost like the Mathematics Subjects Clas-
sification: K-theory, algebraic geometry, homological algebra, motivic coho-
mology, representation theory, quantum groups, special functions, mathe-
matical physics,...(have we forgotten anything?). We shall not attempt here
the impossible task to describe in few sentences the finesse and depth of
his influential contributions spanned over more than forty years of math-
ematical research. Yet, to give an idea of the area covered by Vadim, we
will quote for example, special functions, Knizhnik-Zamolodchikov equa-
tions interpreted in terms of a Gauss-Manin connection and root system
of a semi-simple Lie algebra, quantum groups, perverse sheaves and D-
modules, local systems over the complement of hyperplane configurations.
One should also note his beautiful studies on chiral agebras where homolog-
ical and homotopical algebras do interfere together and his studies on the
quantum Langlands correspondence motivated by mathematical physics. It
is however clear to us that this multifaceted work is underpinned not so
much by the chase of new results (of which there is no shortage), but by
a relentless desire to *understand* mathematics at some deep level. Vadim
adds a taste for the reading of the classics (among his favorites: Gauss' Dis-
quisitiones Arithmeticae, Jacobi, Eisenstein, Hecke, Weil,...). This readings
are an opportunity for him to regain strength and also to rethink in a new
framework some selected pieces of these great authors.

Perhaps all this could be best described by a joke (told to one of us
by Vadik) which is, as all Jewish jokes are, more a parable than a joke. It
goes like this. A student of a late rabbi is overwhelmed with the wish to see
his former teacher's reward in the afterlife. After much praying he sees his
master in a vision. But what does he see? The rabbi is sitting in the same
shabby room where he used to sit when he was alive, he wears the same
worn out clothes that he used to wear, and he studies the Torah just like he
always did. Nothing has changed! In dismay the student asks the Holy One
(blessed be He): "Is this my master's reward for his righteous and saintly
life, good works and the devout study of the Torah?" "Yes, was the answer,
but now he understands".