Applied/ACMS: Difference between revisions

From UW-Math Wiki
Jump to navigation Jump to search
VisualWikitext
 
(354 intermediate revisions by 17 users not shown)
Line 5: Line 5:
*'''When:''' Fridays at 2:25pm (except as otherwise indicated)
*'''When:''' Fridays at 2:25pm (except as otherwise indicated)
*'''Where:''' 901 Van Vleck Hall
*'''Where:''' 901 Van Vleck Hall
*'''Organizers:''' [http://www.math.wisc.edu/~qinli/ Qin Li], [http://www.math.wisc.edu/~spagnolie/ Saverio Spagnolie] and [http://www.math.wisc.edu/~jeanluc Jean-Luc Thiffeault]
*'''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 2021  ==
== '''Spring 2025''' ==
 
{| cellpadding="8"
{| cellpadding="8"
!align="left" | date
! align="left" |Date
!align="left" | virtual/in-person
! align="left" |Speaker
!align="left" | speaker
! align="left" |Title
!align="left" | title
! align="left" |Host(s)
!align="left" | host(s)
|-
|-
| Sept 10
|Jan 31
|
|[https://people.math.wisc.edu/~tgchandler/ Thomas Chandler] (UW)
|[https://www.math.tamu.edu/~jhu/ Jiuhua Hu] (Texas A&M / UW)
|[[#Chandler|''Fluid–structure interactions in active complex fluids'']]
|''[[Applied/ACMS/absF21#Jiuhua Hu (Texas A&M / UW)|TBA]]''
|Spagnolie
|Chen and Stechmann
|-
|Feb 7
|[https://www.colorado.edu/aps/adrian-fraser Adrian Fraser] (Colorado)
|[[#Fraser|''Destabilization of transverse waves by periodic shear flows'']]
|Spagnolie
|-
|Feb 14
|[https://jrluedtke.github.io/ Jim Luedtke] (UW)
|[[#Luedtke|TBA]]
|Spagnolie
|-
|Feb 21
|[https://zhdankin.physics.wisc.edu/ Vladimir Zhdankin] (UW)
|[[#Zhdankin|TBA]]
|Spagnolie
|-
|-
| Sept 17
|Feb 28
|
|[https://nmboffi.github.io/ Nick Boffi] (CMU)
|[https://math.berkeley.edu/~difang/ Di Fang] (Berkeley)
|[[#Boffi|TBA]]
|''[[Applied/ACMS/absF21#Di Fang (Berkeley)|TBA]]''
|Li
|Li
|-
|-
| Sept 24
|Mar 7
|
|[https://sites.lsa.umich.edu/shankar-lab/ Suraj Shankar] (Michigan)
|[https://www.pnnl.gov/people/lai-yung-ruby-leung/ Ruby Leung] (PNNL)
|[[#Shankar|TBA]]
|''[[Applied/ACMS/absF21#Ruby Leung  (PNNL)|TBA]]''
|Spagnolie
|Chen and Stechmann
|-
|-
| Oct 1
|Mar 14
| Virtual
|[https://lu.seas.harvard.edu/ Yue Lu] (Harvard) '''[Colloquium]'''
|[https://gauss.math.yale.edu/~ya248/ Yariv Aizenbud] (Yale)
|[[#Lu|TBA]]
|''[[Applied/ACMS/absF21#Yariv Aizenbud (Yale)|TBA]]''
|Li
|Saverio, Shamgar
|-
|-
| Oct 8
|Mar 21
|
|[https://people.llnl.gov/vogman1 Genia Vogman] (LLNL)
|[https://mathematics.stanford.edu/people/yuhua-zhu Yuhua Zhu] (Stanford)
|[[#Vogman|TBA]]
|''[[Applied/ACMS/absF21#Yuhua Zhu (Stanford)|TBA]]''
|Li
|Zepeda-Núñez
|-
|-
| Oct 15
|Mar 28
|''Spring Break''
|
|
|[https://sites.google.com/andrew.cmu.edu/franzisw Franziska Webber] (CMU)
|''[[Applied/ACMS/absF21#Franziska Webber (CMU)|TBA]]''
|Li
|-
| Oct 22
| Virtual
||[https://www.rjh.io Russell Hewett] (Virginia Tech)
|''[[Applied/ACMS/absF21#Russell Hewett (Virginia Tech)|TBA]]''
|Zepeda-Núñez
|
|
|-
|-
| Oct 29
|Apr 4
|TBA
|
|
|TBA
|''[[Applied/ACMS/absF21#|TBA]]''
|
|
|-
|-
| Nov 5
|Apr 11
|Virtual
|[https://meche.mit.edu/people/faculty/pierrel@mit.edu Pierre Lermusiaux] (MIT)
|[https://people.maths.ox.ac.uk/vella/ Dominic Vella] (Oxford)
|[[#Lermusiaux|TBA]]
|''[[Applied/ACMS/absF21#Dominic Vella (Oxford)|TBA]]''
|Saverio
|-
| Nov 12
|Virtual
|[https://www.mfarazmand.com/ Mohammad Farazmand] (NCSU)
|''[[Applied/ACMS/absF21#Mohammad Farazmand (NCSU)|TBA]]''
|Chen
|Chen
|
|-
|-
| Nov 19
|Apr 18
|
|[https://www.math.uci.edu/~jxin/ Jack Xin] (UC Irvine) '''[Colloquium]'''
|TBA
|[[#Xin|TBA]]
|''[[Applied/ACMS/absF21#|TBA]]''
|
|-
| Nov 26
|
|Thanksgiving
|
|
|
|-
|-
| Dec 3
|Apr 25
|Virtual
|[https://www-users.cse.umn.edu/~bcockbur/ Bernardo Cockburn] (Minnesota)
|[https://scholar.google.com/citations?user=LlBckhUAAAAJ&hl=en Aseel Farhat] (Florida State University)
|[[#Cockburn|''Transforming stabilization into spaces'']]
|''[[Applied/ACMS/absF21#Aseel Farhat (Florida State University)|TBA]]''
| Stechmann, Fabien
|Smith
|-
|-
| Dec 10
|May 2
|
|[https://sylviaherbert.com/ Sylvia Herbert] (UCSD)
|TBA
|[[#Herbert|TBA]]
|''[[Applied/ACMS/absF21#|TBA]]''
|Chen
|}
|}


== Future semesters ==
==Abstracts==
 
<div id="Chandler">
====Thomas G. J. Chandler (UW)====
Title: Fluid-structure interactions in active complex fluids


*[[Applied/ACMS/Spring2022|Spring 2022]]
Fluid anisotropy is central to many biological systems, from rod-like bacteria that self-assemble into dense swarms that function as fluids, to the cell cytoskeleton where the active alignment of stiff biofilaments is crucial to cell division. Nematic liquid crystals provide a powerful model for studying these complex environments. However, large immersed bodies elastically frustrate these fluids, leading to intricate interactions. This frustration can be alleviated through body deformations, at the cost of introducing internal stresses. Additionally, active stresses, arising from particle motility or molecular activity, disrupt nematic order by driving flows. In this presentation, I will demonstrate how complex variables enable analytical solutions to a broad range of problems, offering key insights into the roles of body geometry, anchoring conditions, interaction dynamics, activity-induced flows, and body deformations in many biological settings.
 
<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.


<div id="Cockburn">
====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.


== 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/Fall2022|Fall 2022]]
*[[Applied/ACMS/Spring2022|Spring 2022]]
*[[Applied/ACMS/Fall2021|Fall 2021]]
*[[Applied/ACMS/Spring2021|Spring 2021]]
*[[Applied/ACMS/Spring2021|Spring 2021]]
*[[Applied/ACMS/Fall2020|Fall 2020]]
*[[Applied/ACMS/Fall2020|Fall 2020]]

Latest revision as of 17:56, 1 February 2025


Applied and Computational Mathematics Seminar


Spring 2025

Date Speaker Title Host(s)
Jan 31 Thomas Chandler (UW) Fluid–structure interactions in active complex fluids Spagnolie
Feb 7 Adrian Fraser (Colorado) Destabilization of transverse waves by periodic shear flows Spagnolie
Feb 14 Jim Luedtke (UW) TBA Spagnolie
Feb 21 Vladimir Zhdankin (UW) TBA Spagnolie
Feb 28 Nick Boffi (CMU) TBA Li
Mar 7 Suraj Shankar (Michigan) TBA Spagnolie
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

Thomas G. J. Chandler (UW)

Title: Fluid-structure interactions in active complex fluids

Fluid anisotropy is central to many biological systems, from rod-like bacteria that self-assemble into dense swarms that function as fluids, to the cell cytoskeleton where the active alignment of stiff biofilaments is crucial to cell division. Nematic liquid crystals provide a powerful model for studying these complex environments. However, large immersed bodies elastically frustrate these fluids, leading to intricate interactions. This frustration can be alleviated through body deformations, at the cost of introducing internal stresses. Additionally, active stresses, arising from particle motility or molecular activity, disrupt nematic order by driving flows. In this presentation, I will demonstrate how complex variables enable analytical solutions to a broad range of problems, offering key insights into the roles of body geometry, anchoring conditions, interaction dynamics, activity-induced flows, and body deformations in many biological settings.

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.

Archived semesters


Return to the Applied Mathematics Group Page

Retrieved from "https://wiki.math.wisc.edu/index.php?title=Applied/ACMS&oldid=28032"