Adrien Douady (; 25 September 1935 – 2 November 2006) was a French
mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems.
Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...
.
Douady was a student of
Henri Cartan at the
École normale supérieure
École may refer to:
* an elementary school in the French educational stages normally followed by secondary education
Secondary education or post-primary education covers two phases on the International Standard Classification of Education sca ...
, and initially worked in
homological algebra
Homological algebra is the branch of mathematics that studies homology in a general algebraic setting. It is a relatively young discipline, whose origins can be traced to investigations in combinatorial topology (a precursor to algebraic topology ...
. His thesis concerned deformations of complex analytic spaces. Subsequently, he became more interested in the work of
Pierre Fatou and
Gaston Julia
Gaston Maurice Julia (3 February 1893 – 19 March 1978) was a French Algerian mathematician who devised the formula for the Julia set. His works were popularized by French mathematician Benoit Mandelbrot; the Julia and Mandelbrot fractals are ...
and made significant contributions to the fields of
analytic geometry and
dynamical systems
In mathematics, a dynamical system is a system in which a function describes the time dependence of a point in an ambient space. Examples include the mathematical models that describe the swinging of a clock pendulum, the flow of water in ...
. Together with his former student
John H. Hubbard, he launched a new subject, and a new school, studying properties of iterated quadratic complex mappings. They made important mathematical contributions in this field of complex dynamics, including a study of the
Mandelbrot set
The Mandelbrot set () is the set of complex numbers c for which the function f_c(z)=z^2+c does not diverge to infinity when iterated from z=0, i.e., for which the sequence f_c(0), f_c(f_c(0)), etc., remains bounded in absolute value.
This ...
. One of their most fundamental results is that the Mandelbrot set is connected; perhaps most important is their theory of renormalization of (polynomial-like) maps. The
Douady rabbit
The Douady rabbit is any of various particular filled Julia sets associated with the parameter near the center period 3 buds of Mandelbrot set for complex quadratic map. It is named after French mathematician Adrien Douady.
Formula
The rab ...
, a quadratic
filled Julia set The filled-in Julia set K(f) of a polynomial f is a Julia set and its interior, non-escaping set
Formal definition
The filled-in Julia set K(f) of a polynomial f is defined as the set of all points z of the dynamical plane that have bounded ...
, is named after him.
Douady taught at the
University of Nice and was a professor at the
Paris-Sud 11 University
Paris-Sud University (French: ''Université Paris-Sud''), also known as University of Paris — XI (or as Université d'Orsay before 1971), was a French research university distributed among several campuses in the southern suburbs of Paris, in ...
, Orsay. He was a member of
Bourbaki[.] and an
invited speaker at the International Congress of Mathematicians
This is a list of International Congresses of Mathematicians Plenary and Invited Speakers. Being invited to talk at an International Congress of Mathematicians has been called "the equivalent, in this community, of an induction to a hall of fame." ...
in 1966 at Moscow and again in 1986 in Berkeley.
He was elected to the
Académie des Sciences
The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at the ...
in 1997, and was featured in the French animation project
Dimensions
In physics and mathematics, the dimension of a mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any point within it. Thus, a line has a dimension of one (1D) because only one coord ...
.
He died after diving into the cold Mediterranean from a favourite spot near his vacation home in the
Var.
His son,
Raphael Douady, is also a noted mathematician and an economist.
See also
*
Beltrami equation
In mathematics, the Beltrami equation, named after Eugenio Beltrami, is the partial differential equation
: = \mu .
for ''w'' a complex distribution of the complex variable ''z'' in some open set ''U'', with derivatives that are locally ''L''2 ...
*
Jessen's icosahedron
*
Kuiper's theorem
In mathematics, Kuiper's theorem (after Nicolaas Kuiper) is a result on the topology of operators on an infinite-dimensional, complex Hilbert space ''H''. It states that the space GL(''H'') of invertible bounded endomorphisms of ''H'' is suc ...
References
External links
*http://picard.ups-tlse.fr/~cheritat/Adrien70/index.php
*
*http://www.math.jacobs-university.de/adrien with a guest book to share your memories
Pictures with Adrien Douady
{{DEFAULTSORT:Douady, Adrien
1935 births
2006 deaths
20th-century French mathematicians
Dynamical systems theorists
Academic staff of CĂ´te d'Azur University
Academic staff of Paris-Sud University
École Normale Supérieure alumni
Members of the French Academy of Sciences
Nicolas Bourbaki
People from La Tronche