At IHES, Oscar E. Lanford III focused on work in dynamical systems theory, including the application of ideas from renormalization group theory to dynamical systems. He was also interested in demonstrations assisted by computer and was in charge of the first computer facilities at IHES.
Oscar E. Lanford III always kept close ties with the Institute. He even acted as interim Director for the Institute from 2007 to 2011, during the research trips abroad of the former Director, Jean-Pierre Bourguignon.
Oscar E. Lanford III passed away on November 16, 2013. He had wished to donate an apartment to the Institute: “a way of giving something back in return for the many opportunities that had been offered to him over the years,” explained his wife and daughter.
IHES wanted to honor Oscar by naming the Director’s science office after him, in perpetuity.
Read Arthur Jaffe’s tribute to Oscar E. Lanford III here.
Born on May 4, 1923, in Roanne (Loire, France) and a graduate engineer from the École Polytechnique, Professor Louis Michel obtained his thesis on the theory of weak interaction at the University of Manchester in 1953. He started teaching in Lille, then in Orsay, and in 1958 he created the Centre de Physique Théorique at the École Polytechnique.
Only four years after the creation of IHES by Léon Motchane, he joined the Institute in 1962 and became the first permanent professor in theoretical physics at IHES. Then, he oriented his work towards crystallography. Major world figure in the theory of elementary particles, he had many international students.
Louis Michel was also president of the Société Française de Physique from 1978 to 1980 and was doctor honoris causa of the universities of Louvain and Barcelona. In 1984, he received the Wigner Medal, administered by The Group Theory and Fundamental Physics Foundation, which recognizes outstanding contributions to the understanding of physics through group theory.
On December 30, 1999, Louis Michel passed away. With 30 years at IHES, he marked the history of the Institute. In order to honor his memory, IHES created the Louis Michel Chair for distinguished long-term visitors.
Jean Dieudonné was notably a founding member of Bourbaki and the writer of the group. He was also a PhD advisor of Grothendieck at the University of Nancy and later convinced Léon Motchane to hire his brilliant student alongside him. They thus became the first two IHES professors.
Between 1959 and 1979 Dieudonné was the editor-in-chief of the Publications Mathématiques de l’IHES, which rapidly ranked among the best mathematics journals in the world. He devoted most of his time to properly write the famous Éléments de Géométrie Algébrique (“Elements of Algebraic Geometry”) in order to let Grothendieck focus on his seminars.
Jean Dieudonné left Bures for the new University of Nice in 1964 to found its department of mathematics. Between 1969 and 1982, he published there his Éléments d’analyse (Treatise on Analysis) in nine volumes; it is an imposing textbook containing many substantial exercises for students – and still in use today.
Alexander Grothendieck marked the history of mathematics in a deep way. Hailed as one of the most influential mathematicians of the 20th century, he considered himself a “cathedral builder”. His ambitious program of fusion between arithmetic, algebraic geometry, and topology continues to structure contemporary mathematics.
When Léon Motchane founded IHES in 1958, he asked Jean Dieudonné to become the first permanent professor. Dieudonné accepted with one condition: to also recruit Alexander Grothendieck. Then, IHES became the host of one of the most extraordinary seminars in mathematics the “Séminaire de géométrie algébrique de Grothendieck”.
Grothendieck’s requirement, originality, and generosity founded the spirit of the Institute. This level of excellence that he brought is now a major asset as well as a responsibility for the Institute.
Recently, Cédric Deffayet continued his research on massive gravity and field theories with actions containing derivative interactions and/or superior derivatives. For the first time, he thus obtained the formulation of a theory of a massive graviton propagating over an arbitrary space-time. He was able to deduce the existence of partially zero-mass gravitons (called PM) on non-Einstein space-time.
Cédric Deffayet also studied the question of the construction of coherent interactions for a multiplet of PM gravitons on Anti-de Sitter spaces, proving a uniqueness theorem for a cubic interaction. Continuing this work, a consistent and completely non-linear theory was obtained for the first time for two or more PM gravitons.
Cédric Deffayet also studied the coupling to matter in certain scalar-tensor theories of the type “beyond the Horndeski theories” and has been able to characterize different cases depending on whether or not this coupling changes the counting of degrees of freedom. Finally, domain walls of a new type (unsupported by a potential) have been highlighted in scalar theories of the “k-essence” type.
