# Difference between revisions of "Fall 2021 and Spring 2022 Analysis Seminars"

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=== Xianghong Chen (UW Milwaukee) === | === Xianghong Chen (UW Milwaukee) === | ||

− | ''Restricting the Fourier transform to some oscillating curves | + | ''Restricting the Fourier transform to some oscillating curves'' |

I will talk about Fourier restriction to some compact smooth curves. The problem is relatively well understood for curves with nonvanishing torsion due to work of Drury from the 80's, but is less so for curves that contain 'flat' points (i.e. vanishing torsion). Sharp results are known for some monomial-like or finite type curves by work of Bak-Oberlin-Seeger, Dendrinos-Mueller, and Stovall, where a geometric inequality (among others) plays an important role. Such an inequality fails to hold if the torsion demonstrates strong sign-changing behavior, in which case endpoint restriction bounds may fail. In this talk I will present how one could obtain sharp non-endpoint results for certain space curves of this kind. Our approach uses a covering lemma for smooth functions that strengthens a variation bound of Sjolin, who used it to obtain a similar result for plane curves. This is joint work with Dashan Fan and Lifeng Wang. | I will talk about Fourier restriction to some compact smooth curves. The problem is relatively well understood for curves with nonvanishing torsion due to work of Drury from the 80's, but is less so for curves that contain 'flat' points (i.e. vanishing torsion). Sharp results are known for some monomial-like or finite type curves by work of Bak-Oberlin-Seeger, Dendrinos-Mueller, and Stovall, where a geometric inequality (among others) plays an important role. Such an inequality fails to hold if the torsion demonstrates strong sign-changing behavior, in which case endpoint restriction bounds may fail. In this talk I will present how one could obtain sharp non-endpoint results for certain space curves of this kind. Our approach uses a covering lemma for smooth functions that strengthens a variation bound of Sjolin, who used it to obtain a similar result for plane curves. This is joint work with Dashan Fan and Lifeng Wang. |

## Revision as of 15:23, 16 January 2017

**Analysis Seminar**
Current Semester

The seminar will meet Tuesdays, 4:00 p.m. in VV B139, unless otherwise indicated.

If you wish to invite a speaker please contact Andreas at seeger(at)math

### Previous Analysis seminars

# Analysis Seminar Schedule Spring 2017

date | speaker | title | host(s) | |
---|---|---|---|---|

January 17, Math Department Colloquium | Fabio Pusateri (Princeton) | The Water Waves Problem | Angenent | |

January 24 | Tamás Darvas (Maryland) | TBA | Viaclovsky | |

Monday, January 30, 3:30, VV901 (PDE Seminar) | Serguei Denissov (UW) | Title | ||

March 7, Mathematics Department Distinguished Lecture | Roger Temam (Indiana) | TBA | Smith | |

Wednesday, March 8, Joint Applied Math/PDE/Analysis Seminar | Roger Temam (Indiana) | TBA | Smith | |

March 14 | Xianghong Chen (UW Milwaukee) | Restricting the Fourier transform to some oscillating curves | Seeger | |

March 21 | SPRING BREAK | |||

March 28 | Brian Cook (Fields Institute) | TBA | Seeger |

# Abstracts

### Fabio Pusateri (Princeton)

*The Water Waves problem*

We will begin by introducing the free boundary Euler equations which are a system of nonlinear PDEs modeling the motion of fluids, such as waves on the surface of the ocean. We will discuss several works done on this system in recent years, and how they fit into the broader context of the study of nonlinear evolution problems. We will then focus on the question of global regularity for water waves, present some of our main results - obtained in collaboration with Ionescu and Deng-Ionescu-Pausader - and sketch some of the main ideas.

### Xianghong Chen (UW Milwaukee)

*Restricting the Fourier transform to some oscillating curves*

I will talk about Fourier restriction to some compact smooth curves. The problem is relatively well understood for curves with nonvanishing torsion due to work of Drury from the 80's, but is less so for curves that contain 'flat' points (i.e. vanishing torsion). Sharp results are known for some monomial-like or finite type curves by work of Bak-Oberlin-Seeger, Dendrinos-Mueller, and Stovall, where a geometric inequality (among others) plays an important role. Such an inequality fails to hold if the torsion demonstrates strong sign-changing behavior, in which case endpoint restriction bounds may fail. In this talk I will present how one could obtain sharp non-endpoint results for certain space curves of this kind. Our approach uses a covering lemma for smooth functions that strengthens a variation bound of Sjolin, who used it to obtain a similar result for plane curves. This is joint work with Dashan Fan and Lifeng Wang.