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BEGIN:VEVENT
SUMMARY:Nicola Guglielmi (Gran Sasso Science Institute (Italy))
DTSTART:20201217T133000Z
DTEND:20201217T143000Z
DTSTAMP:20260415T194929Z
UID:DAIDAY2020/1
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/DAIDAY2020/1
 /">Approximating Lyapunov exponents of switching systems</a>\nby Nicola Gu
 glielmi (Gran Sasso Science Institute (Italy)) as part of Third DinAmicI D
 ay\n\n\nAbstract\nIn this talk I will discuss a new approach for construct
 ing polytope Lyapunov \nfunctions for continuous-time linear switching sys
 tems. The proposed method \nallows to decide the uniform stability of a sw
 itching system and to compute \nthe associated Lyapunov exponent with an a
 rbitrary precision. \nThe method relies on the discretization of the syste
 m and provides - for any \ngiven discretization stepsize - a lower and an 
 upper bound for the Lyapunov \nexponent.\nThen I will briefly discuss asym
 ptotic stability of continuous-time systems with mode-dependent guarantee
 d dwell time. These systems are reformulated as special cases of a genera
 l class of mixed (discrete-continuous) linear switching systems on graphs
 \, in which some modes correspond to discrete actions and some others cor
 respond to continuous-time evolutions.I will give a few examples to illust
 rate the methodology.\n\nMainly inspired by joint works with Vladimir Yu. 
 Protasov (U. L’Aquila and\nMoscow State U.) and Marino Zennaro (U. Tries
 te).\n
LOCATION:https://researchseminars.org/talk/DAIDAY2020/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anna Florio (Sorbonne Université (France))
DTSTART:20201217T143000Z
DTEND:20201217T153000Z
DTSTAMP:20260415T194929Z
UID:DAIDAY2020/2
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/DAIDAY2020/2
 /">Spectral rigidity of contact 3D Axiom A flows</a>\nby Anna Florio (Sorb
 onne Université (France)) as part of Third DinAmicI Day\n\n\nAbstract\nW
 e show a rigidity result for two 3-dimensional contact Axiom A flows. More
  precisely\, if the restriction of the flows to some basic set is orbit eq
 uivalent and iso-length-spectral\, then the dynamics on the basic sets are
  conjugated through a homeomorphism of class $C^{1\,\\beta}$\, in Whitney 
 sense\, for some $\\beta\\in(0\,1)$\, which also preserves the contact str
 uctures. The ideas are reminiscent of the work of Otal. As a consequence\,
  interesting spectral rigidity results can be deduced for $C^k$ open dispe
 rsing billiards. This is a joint work with Martin Leguil.\n
LOCATION:https://researchseminars.org/talk/DAIDAY2020/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sara Di Ruzza (Università degli studi di Padova (Italy))
DTSTART:20201218T133000Z
DTEND:20201218T143000Z
DTSTAMP:20260415T194929Z
UID:DAIDAY2020/3
DESCRIPTION:by Sara Di Ruzza (Università degli studi di Padova (Italy)) 
 as part of Third DinAmicI Day\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/DAIDAY2020/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emanuele Haus (Università Roma Tre (Italy))
DTSTART:20201218T143000Z
DTEND:20201218T153000Z
DTSTAMP:20260415T194929Z
UID:DAIDAY2020/4
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/DAIDAY2020/4
 /">Normal form and existence time for the Kirchhoff equation</a>\nby Emanu
 ele Haus (Università Roma Tre (Italy)) as part of Third DinAmicI Day\n\n
 \nAbstract\nIn this talk I will present some recent results on the Kirchho
 ff equation with periodic boundary conditions\, in collaboration with Piet
 ro Baldi.\nComputing the first step of quasilinear normal form\, we erase 
 from the equation all the cubic terms giving nonzero contribution to the e
 nergy estimates\; thus we deduce that\, for small initial data of size $\\
 varepsilon$ in Sobolev class\, the time of existence of the solution is at
  least of order $\\varepsilon^{-4}$ (which improves the lower bound $\\var
 epsilon^{-2}$ coming from the linear theory).\nIn the second step of norma
 l form\, there remain some resonant terms (which cannot be erased) that gi
 ve a non-trivial contribution to the energy estimates\; this could be inte
 rpreted as a sign of non-integrability of the equation. Nonetheless\, we s
 how that small initial data satisfying a suitable nonresonance condition p
 roduce solutions that exist over a time of order at least $\\varepsilon^{-
 6}$.\n
LOCATION:https://researchseminars.org/talk/DAIDAY2020/4/
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