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<DIV><FONT face=Arial size=2>Gentile Prof./dott.,</FONT></DIV>
<DIV><FONT face=Arial size=2>la avvertiamo che nei prossimi giorni alla Scuola
Normale si terrà il seguente seminario di matematica nell'ambito del Colloquio
De Giorgi:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Giovedì 8 maggio 2003, alle ore 15:00 in Aula
Mancini,</FONT></DIV>
<DIV><FONT face=Arial size=2><STRONG>Prof. Yakov Pesin</STRONG> - Pennsylvania
State University - </FONT></DIV>
<DIV><FONT face=Arial size=2>"Is chaotic behavior typical among dynamical
systems?"</FONT></DIV>
<DIV align=left><FONT><FONT face=Arial size=2>Abstract: </FONT></FONT></DIV>
<DIV align=left><FONT><FONT face=Arial size=2>The hyperbolic theory of dynamical
systems provides a mathematical foundation for the paradigm that is widely known
as "deterministic chaos" --<BR>the appearance of irregular chaotic motions in
purely deterministic dynamical<BR>systems. This phenomenon is considered as one
of the most fundamental<BR>discoveries in the theory of dynamical systems in the
second part of the last<BR>century. The hyperbolic behavior can be interpreted
in various ways and the<BR>weakest one is associated with dynamical systems with
non-zero Lyapunov<BR>exponents.<BR>I will discuss some recent progress in the
still-open problem of whether<BR>dynamical systems with non-zero Lyapunov
exponents are typical. I will also<BR>outline some relations between this
problem and recent advances in the<BR>Pugh-Shub stable ergodicity
theory.</FONT></FONT></DIV>
<DIV><FONT><FONT face=Arial size=2></FONT></FONT> </DIV>
<DIV><FONT><FONT face=Arial size=2>Cordiali saluti</FONT></FONT></DIV>
<DIV><FONT><FONT face=Arial size=2>SEGRETERIA CLASSE DI SCIENZE</DIV>
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<DIV align=left><BR><BR></DIV></FONT>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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