Constantino Tsallis

Constantino Tsallis
File:Constantino Tsallis February 2010.jpg Constantino Tsallis in 2010.
Born	1943 Athens, Greece
Residence	Rio de Janeiro, Brazil
Citizenship	Brazilian
Nationality	Greek
Fields	Theoretical physics
Institutions	Centro Brasileiro de Pesquisas Físicas (Brazilian Physics Research Center)
Alma mater	University of Paris-Orsay
Known for	Tsallis entropy and Tsallis statistics
Notable awards	Member, Brazilian Academy of Sciences

Constantino Tsallis (Greek: Κωνσταντίνος Τσάλλης; born 1943) is a naturalized Brazilian physicist working in Rio de Janeiro at CBPF, Brazil. He was born in Greece, and grew up in Argentina, where he studied physics at Instituto Balseiro, in Bariloche. In 1974, he received a Doctorat d'Etat et Sciences Physiques degree from the University of Paris-Orsay. He moved to Brazil in 1975 with his wife and daughter.

Tsallis is credited with introducing the notion of what is known as Tsallis entropy and Tsallis statistics in his 1988 paper "Possible generalization of Boltzmann–Gibbs statistics" published in the Journal of Statistical Physics. The generalization is considered to be a good candidate for formulating a theory of non-extensive thermodynamics. The resulting theory is not intended to replace Boltzmann–Gibbs statistics, but rather supplement it, such as in the case of anomalous systems characterised by non-ergodicity or metastable states.

One experimental verification of the predictions of Tsallis statistics concerned cold atoms in dissipative optical lattices. Eric Lutz made an analytical prediction in 2003 which was verified in 2006 by a London team.

Tsallis conjectured in 1999 (Brazilian Journal of Physics 29, 1; Figure 4):

1. That a longstanding quasi-stationary state (QSS) was expected in long-range interacting Hamiltonian systems (one of the core problems of statistical mechanics). This was verified by groups around the world.
2. That this QSS should be described by Tsallis statistics instead of Boltzmann–Gibbs statistics. This was verified in June 2007 by Pluchino, Rapisarda and Tsallis (in the last figure, instead of the Maxwellian (Gaussian) distribution of velocities (valid for short-range interactions), one sees a q-Gaussian).

External links

• Homepage of Constantino Tsallis
• The regularly updated link to the literature of nonextensive statistics