Diogo Arsénio, Nicolas Lerner

Research output: Contribution to journalArticlepeer-review


We introduce a new approach to velocity-averaging lemmas in kinetic theory. This approach — based upon the classical energy method — provides a powerful duality principle in kinetic transport equations which allows for a natural extension of classical averaging lemmas to previously unknown cases where the density and the source term belong to dual spaces. More generally, this kinetic duality principle produces regularity results where one can trade a loss of regularity or integrability somewhere in the kinetic transport equation for a suitable opposite gain elsewhere. Also, it looks simpler and more robust to rely on proving inequalities instead of constructing exact parametrices. The results in this article are introduced from a functional analytic point of view. They are motivated by the abstract regularity theory of kinetic transport equations. However, recall that velocity-averaging lemmas have profound implications in kinetic theory and its related physical models. In particular, the precise formulation of such results has the potential to lead to important applications to the regularity of renor-malizations of Boltzmann-type equations, as well as kinetic formulations of gas dynamics, for instance.

Original languageEnglish (US)
Pages (from-to)319-362
Number of pages44
JournalPure and Applied Analysis
Issue number2
StatePublished - 2021


  • averaging lemmas
  • dispersion
  • duality principle
  • energy method
  • hypoellipticity
  • kinetic transport equation
  • maximal regularity

ASJC Scopus subject areas

  • Analysis
  • Mathematical Physics


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