*Si comunica che il Seminario del prof. Giorgio Stefani si terrà in aula Fermi, anziché in aula Volterra come precedentemente comunicato.*

*Avviso Seminari di Matematica*

Mercoledì 17 novembre 2021

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ore 14:30

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  (Aula Fermi)

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Scuola Normale Superiore

Pisa

*Giorgio Stefani* (University of Basel)

terrà un seminario dal titolo:

*" An elementary proof of existence and uniqueness for the Euler flow in localized Yudovich spaces"*

*abstract:*

• We revisit Yudovich’s well-posedness result for the 2-dimensional Euler

equations for an inviscid incompressible fluid. Existence of global-in-time weak solutions holds in suitable uniformly-localized versions of the Lebesgue space and of the Yudovich space, respectively, for the vorticity, with explicit modulus of continuity for the associated velocity. Uniqueness of weak solutions, in contrast to Yudovich’s energy method, follows from a Lagrangian comparison. Our entire argument relies on elementary real-variable techniques, with no use of either Sobolev spaces, Calderón-Zygmund theory or Littlewood-Paley decomposition, and actually applies not only to the Biot-Savart law, but also to more general operators whose kernels obey some natural structural assumptions. This is a joint work in collaboration with Gianluca Crippa. *

il seminario si terrà in modalità mista. Tutti gli interessati a partecipare in presenza devono contattare per email il dr. Gioacchino Antonelli (gioacchino.antonelli@sns.it). link per collegarsi all'evento: https://teams.microsoft.com/l/meetup-join/19%3aU6a57NlVFWbcy9kcfM4uzZIySQNcU...

Classe di Scienze Valeria Giuliani Scuola Normale Superiore Servizio Attività Didattiche tel. 050 509260 Piazza dei Cavalieri, 7 56126 Pisa E-mail: valeria.giuliani@sns.it E-mail: classi@sns.it