Applied/ACMS: Difference between revisions

From UW-Math Wiki
Jump to navigation Jump to search
VisualWikitext
 
(172 intermediate revisions by 11 users not shown)
Line 6: Line 6:
*'''Where:''' 901 Van Vleck Hall
*'''Where:''' 901 Van Vleck Hall
*'''Organizers:'''  [https://math.wisc.edu/staff/fabien-maurice/ Maurice Fabien], [https://people.math.wisc.edu/~rycroft/ Chris Rycroft], and [https://www.math.wisc.edu/~spagnolie/ Saverio Spagnolie],  
*'''Organizers:'''  [https://math.wisc.edu/staff/fabien-maurice/ Maurice Fabien], [https://people.math.wisc.edu/~rycroft/ Chris Rycroft], and [https://www.math.wisc.edu/~spagnolie/ Saverio Spagnolie],  
*'''To join the ACMS mailing list:''' Send mail to [mailto:acms+join@g-groups.wisc.edu acms+join@g-groups.wisc.edu].
*'''To join the ACMS mailing list:''' Send mail to [mailto:acms+join@g-groups.wisc.edu acms+subscribe@g-groups.wisc.edu].


<br>   
<br>   


== Fall 2023  ==
== '''Spring 2025''' ==
 
{| cellpadding="8"
{| cellpadding="8"
!align="left" | date
! align="left" |Date
!align="left" | speaker
! align="left" |Speaker
!align="left" | title
! align="left" |Title
!align="left" | host(s)
! align="left" |Host(s)
|-
|-
| Sep 8
|Jan 31
|[https://webspace.clarkson.edu/~ebollt/ Erik Bollt] (Clarkson University)
|[https://people.math.wisc.edu/~tgchandler/ Thomas Chandler] (UW)
|A New View on Integrability: On Matching Dynamical Systems through Koopman Operator Eigenfunctions
|[[#Chandler|TBA]]
| Chen
|
|-
|-
| Sep 15
|Feb 7
|[https://math.yale.edu/people/john-schotland John Schotland] (Yale University)
|[https://www.colorado.edu/aps/adrian-fraser Adrian Fraser] (Colorado)
|
|[[#Fraser|''Destabilization of transverse waves by periodic shear flows'']]
| Li
|Spagnolie
|-
|-
|Sep 22
|Feb 14
|[https://sites.google.com/view/balazsboros Balazs Boros] (U Vienna)
|TBA
|
|
|Craciun
|-
| Sep 29
|[https://data-assimilation-causality-oceanography.atmos.colostate.edu/ Peter Jan van Leeuwen] (Colorado State University)
|
|
| Chen
|-
| '''Wed Oct 4'''
|[https://www.damtp.cam.ac.uk/person/est42/ Edriss Titi] (Cambridge/Texas A&M)
|''[[Applied/ACMS/absF23#Edriss Titi (Cambridge/Texas A&M)|Distringuished Lecture Series]]''
| Smith, Stechmann
|-
|-
| Oct 6
|Feb 21
| No Friday seminar
|TBA
| Distinguished lecture this week on Wednesday
|
|
|-
| Oct 13
| [https://geosci.uchicago.edu/people/da-yang/ Da Yang] (University of Chicago)
|
|
|Smith
|-
|-
| Oct 20
|Feb 28
|[https://www.stat.uchicago.edu/~ykhoo/ Yuehaw Khoo] (University of Chicago)
|[https://nmboffi.github.io/ Nick Boffi] (CMU)
|
|[[#Boffi|TBA]]
|Li
|Li
|-
|-
| Oct 27
|Mar 7
|[https://shukaidu.github.io/ Shukai Du] (UW)
|TBA
|
|
|Stechmann
|-
| Nov 3
|[https://www.math.arizona.edu/~lmig/ Lise-Marie Imbert-Gérard] (University of Arizona)
|
|
|Rycroft
|-
|-
| Nov 10
|Mar 14
| [https://as.tufts.edu/physics/people/faculty/timothy-atherton Timothy Atherton] (Tufts)
|[https://lu.seas.harvard.edu/ Yue Lu] (Harvard) '''[Colloquium]'''
|
|[[#Lu|TBA]]
|Chandler, Spagnolie
|Li
|-
|-
| Nov 17
|Mar 21
|[https://klotsagroup.wixsite.com/home Daphne Klotsa]
|[https://people.llnl.gov/vogman1 Genia Vogman] (LLNL)
|
|[[#Vogman|TBA]]
|Rycroft
|Li
|-
|-
| Nov 24
|Mar 28
| Thanksgiving break
|''Spring Break''
|
|
|
|
|-
|-
| Dec 1
|Apr 4
|TBA
|
|
|
|
|-
|Apr 11
|[https://meche.mit.edu/people/faculty/pierrel@mit.edu Pierre Lermusiaux] (MIT)
|[[#Lermusiaux|TBA]]
|Chen
|-
|Apr 18
|[https://www.math.uci.edu/~jxin/ Jack Xin] (UC Irvine) '''[Colloquium]'''
|[[#Xin|TBA]]
|
|
|-
|-
| Dec 8
|Apr 25
|
|[https://www-users.cse.umn.edu/~bcockbur/ Bernardo Cockburn] (Minnesota)
|
|[[#Cockburn|''Transforming stabilization into spaces'']]
|
| Stechmann, Fabien
|-
|-
|Pending
|May 2
|Invite sent to Talea Mayo
|[https://sylviaherbert.com/ Sylvia Herbert] (UCSD)
|
|[[#Herbert|TBA]]
|Fabien
|Chen
|}
|}


== Future semesters ==
==Abstracts==


*[[Applied/ACMS/Spring2024|Spring 2024]]
<div id="Fraser">
====Adrian Fraser (Colorado)====
Title: Destabilization of transverse waves by periodic shear flows
 
Periodic shear flows have the peculiar property that they are unstable to large-scale, transverse perturbations, and that this instability proceeds via a negative-eddy-viscosity mechanism (Dubrulle & Frisch, 1991). In this talk, I will show an example where this property causes transverse waves to become linearly unstable: a sinusoidal shear flow in the presence of a uniform, streamwise magnetic field in the framework of incompressible MHD. This flow is unstable to a KH-like instability for sufficiently weak magnetic fields, and uniform magnetic fields permit transverse waves known as Alfvén waves. Under the right conditions, these Alfvén waves become unstable, presenting a separate branch of instability that persists for arbitrarily strong magnetic fields which otherwise suppress the KH-like instability. After characterizing these waves with the help of a simple asymptotic expansion, I will show that they drive soliton-like waves in nonlinear simulations. With time permitting, I will discuss other fluid systems where similar dynamics are or may be found, including stratified flows and plasma drift waves.
 
====Bernardo Cockburn (Minnesota)====
Title: Transforming stabilization into spaces


In the framework of finite element methods for ordinary differential equations, we consider the continuous Galerkin method (introduced in 72) and the discontinuous Galerkin method (introduced in 73/74). We uncover the fact that both methods discretize the time derivative in exactly the same form, and discuss a few of its consequences. We end by briefly describing our ongoing work on the extension of this result to some Galerkin methods for partial differential equations.


----
<div id="Bal"><div id="Portone"><div id="Damle"><div id="Sprague"><div id="Holmes-Cerfon"><div id="Sun"><div id="Maxian"><div id="Lavi">


== Archived semesters ==
== Archived semesters ==


*[[Applied/ACMS/Fall2024|Fall 2024]]
*[[Applied/ACMS/Spring2024|Spring 2024]]
*[[Applied/ACMS/Fall2023|Fall 2023]]
*[[Applied/ACMS/Spring2023|Spring 2023]]
*[[Applied/ACMS/Spring2023|Spring 2023]]
*[[Applied/ACMS/Fall2022|Fall 2022]]
*[[Applied/ACMS/Fall2022|Fall 2022]]

Latest revision as of 21:41, 22 January 2025


Applied and Computational Mathematics Seminar


Spring 2025

Date Speaker Title Host(s)
Jan 31 Thomas Chandler (UW) TBA
Feb 7 Adrian Fraser (Colorado) Destabilization of transverse waves by periodic shear flows Spagnolie
Feb 14 TBA
Feb 21 TBA
Feb 28 Nick Boffi (CMU) TBA Li
Mar 7 TBA
Mar 14 Yue Lu (Harvard) [Colloquium] TBA Li
Mar 21 Genia Vogman (LLNL) TBA Li
Mar 28 Spring Break
Apr 4 TBA
Apr 11 Pierre Lermusiaux (MIT) TBA Chen
Apr 18 Jack Xin (UC Irvine) [Colloquium] TBA
Apr 25 Bernardo Cockburn (Minnesota) Transforming stabilization into spaces Stechmann, Fabien
May 2 Sylvia Herbert (UCSD) TBA Chen

Abstracts

Adrian Fraser (Colorado)

Title: Destabilization of transverse waves by periodic shear flows

Periodic shear flows have the peculiar property that they are unstable to large-scale, transverse perturbations, and that this instability proceeds via a negative-eddy-viscosity mechanism (Dubrulle & Frisch, 1991). In this talk, I will show an example where this property causes transverse waves to become linearly unstable: a sinusoidal shear flow in the presence of a uniform, streamwise magnetic field in the framework of incompressible MHD. This flow is unstable to a KH-like instability for sufficiently weak magnetic fields, and uniform magnetic fields permit transverse waves known as Alfvén waves. Under the right conditions, these Alfvén waves become unstable, presenting a separate branch of instability that persists for arbitrarily strong magnetic fields which otherwise suppress the KH-like instability. After characterizing these waves with the help of a simple asymptotic expansion, I will show that they drive soliton-like waves in nonlinear simulations. With time permitting, I will discuss other fluid systems where similar dynamics are or may be found, including stratified flows and plasma drift waves.

Bernardo Cockburn (Minnesota)

Title: Transforming stabilization into spaces

In the framework of finite element methods for ordinary differential equations, we consider the continuous Galerkin method (introduced in 72) and the discontinuous Galerkin method (introduced in 73/74). We uncover the fact that both methods discretize the time derivative in exactly the same form, and discuss a few of its consequences. We end by briefly describing our ongoing work on the extension of this result to some Galerkin methods for partial differential equations.

Retrieved from "https://wiki.math.wisc.edu/index.php?title=Applied/ACMS&oldid=27893"