News & Events

Department Events

Events

• Oct

  15

  Appl Math: Trevor GrandPre on "Model-free Inference from Time-series Data"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:15 AM M416, Technological Institute

  EVENT DETAILS

  Title: Model-free Inference from Time-series Data

  Speaker: Trevor GrandPre, Princeton University

  Abstract: Drawing inferences from experimental data often involves imposing models, which can lead to inaccurate conclusions. Theory sometimes points to quantities that are significant independent of the underlying mechanisms, but making accurate model-free estimates of these quantities can be hard because finite data generates systematic errors. I present two cases where we develop new methods to address and correct these errors: (1) extracting long-term population growth from single-cell lineage data and (2) estimating the evidence for the arrow of time in patterns of neural activity. For population growth, key observables are the number of divisions and generation times along a lineage for a fixed time. Simple growth rate estimators suffer from finite-time bias at short times; this bias scales inversely with time and can be corrected. At longer times, rare events introduce a linearization bias, causing an abrupt phase transition explained by a simple model of disordered systems. Our approach yields accurate estimates provided the lineage counts and lengths stay below the critical point, allowing inference of how mutations and physiological variations impact fitness. In the case of neural activity, the relevant observables are the moments of activity and the waiting times between these moments. Estimating the irreversibility—quantified by the Kullback-Leibler divergence between the distribution of forward and backward trajectories—faces similar biases. Finding the systematic dependence of these biases on sample size allows for accurate estimates, including detecting systems that obey detailed balance, and opens a path to exploring how the brain represents the arrow of time. Generally, this new understanding of how model-free estimators rely on a complex order of limits of the amount of data and the length of each sample may allow quantitative understanding of other relevant processes such as gene regulation, cell-cycle dynamics, and signal transduction.

  Zoom: https://northwestern.zoom.us/j/92938364014

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Tuesday, October 15, 2024 at 11:15 AM - 12:15 PM

  LOCATION M416, Technological Institute    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Oct

  4

  Appl Math: Rebecca Willett on "Mathematics in Scientific Machine Learning"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:00 AM Ruan Conference Room - lower level, Chambers Hall

  EVENT DETAILS

  Title: Mathematics in Scientific Machine Learning

  Speaker: Rebecca Willett, University of Chicago

  Abstract: Artificial intelligence (AI) and machine learning (ML) are poised to
  revolutionize the pace and nature of scientific discovery. The widespread adoption
  of AI in the sciences has the potential to integrate scientific inquiry with modes of
  hypothesis generation, data analysis, experimental design, and simulation,
  transforming our capacity to address scientific problems that currently seem
  insurmountable. The mathematical foundations of AI and ML are crucial for highquality,
  reproducible, AI-enabled scientific research. However, blindly applying AI
  and ML poses significant risks, such as the rapid acceleration of the "reproducibility
  crisis" in science. In this talk, I will discuss fundamental machine learning
  challenges and opportunities that are particularly relevant to scientific discovery,
  such as emulators, generative models, and inverse problems. These problems
  underscore the importance of incorporating mathematical and physical models as
  well as numerical algorithms into ML frameworks, highlighting exciting directions for
  future work.

  Special Note: Unusual Location and day: As a joint colloquium with the Department of Statistics and Data Science this talk is on Friday at 11 in Chambers Hall.

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Friday, October 4, 2024 at 11:00 AM - 12:00 PM

  LOCATION Ruan Conference Room - lower level, Chambers Hall    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Oct

  8

  Appl Math: Krishna Shrinivas on "The Many Phases of a Cell"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:15 AM M416, Technological Institute

  EVENT DETAILS

  Title: The Many Phases of a Cell

  Speaker: Krishna Shrinivas, Northwestern University

  Abstract: Cells routinely orchestrate reactions, interactions, and transport amongst billions of biomolecules in a crowded environment to perform the diverse tasks that underpin life. Rather than occurring in a well-mixed milieu, biomolecules self-organize into dozens of membrane-lacking compartments called condensates that enable key biological functions and are aberrant in disease. I will introduce how phase transitions are emerging as a paradigm underlying condensate assembly and function in cells. During the talk, I will describe our efforts that bridge statistical physics, applied mathematics, and computation to predict emergent multiphase behavior in highly multicomponent soft materials and how such materials can be designed to perform information processing or computational tasks.

  Zoom: https://northwestern.zoom.us/j/98009465839

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Tuesday, October 8, 2024 at 11:15 AM - 12:15 PM

  LOCATION M416, Technological Institute    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Oct

  21

  Appl Math: Kate Stebe on "Swimming in Nematic Liquid Crystals"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:15 AM M416, Technological Institute

  EVENT DETAILS

  Title: Swimming in Nematic Liquid Crystals

  Speaker: Kate Stebe, University of Pennsylvania

  Abstract: Purcell's scallop theorem, which requires non-reciprocal motions for translation in isotropic fluids, needs adjustment for swimmers in nematic liquid crystals (NLC). Unlike isotropic fluids, where complex, non-reciprocal motions are essential, symmetric motions can induce translation in NLC due to its anisotropic nature. In NLC, symmetric flows create broken symmetries and elastic stresses that drive motion, expanding the range of effective swim strokes. This study outlines the conditions for swimming at low Reynolds numbers in NLC and explores how colloidal swimmers can access far-from-equilibrium defect dynamics that enhance swimming efficiency. The research, in collaboration with Miha Ravnik's group, reveals new possibilities for effective swimming in NLC environments.

  Special Note: Stephen H. Davis Lecture

  Zoom: https://northwestern.zoom.us/j/97615086394

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Monday, October 21, 2024 at 11:15 AM - 12:15 PM

  LOCATION M416, Technological Institute    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Oct

  29

  Appl Math: Pedram Hassanzadeh on "Title TBA"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:15 AM M416, Technological Institute

  EVENT DETAILS

  Title: TBA

  Speaker: Pedram Hassanzadeh, The University of Chicago

  Abstract: TBA

  Zoom: TBA

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Tuesday, October 29, 2024 at 11:15 AM - 12:15 PM

  LOCATION M416, Technological Institute    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Nov

  5

  Appl Math: Miranda Holmes-Cerfon on "Title TBA"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:15 AM M416, Technological Institute

  EVENT DETAILS

  Title: TBA

  Speaker: Miranda Holmes-Cerfon, The University of British Columbia

  Abstract: TBA

  Zoom: TBA

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Tuesday, November 5, 2024 at 11:15 AM - 12:15 PM

  LOCATION M416, Technological Institute    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Nov

  12

  Appl Math: Mariela Petkova on "Title TBA"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:15 AM M416, Technological Institute

  EVENT DETAILS

  Title: TBA

  Speaker: Mariela Petkova

  Abstract: TBA

  Zoom: TBA

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Tuesday, November 12, 2024 at 11:15 AM - 12:15 PM

  LOCATION M416, Technological Institute    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Nov

  19

  Appl Math: Ertugrul Ozbudak on "Title TBA"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:15 AM M416, Technological Institute

  EVENT DETAILS

  Title: TBA

  Speaker: Ertugrul Ozbudak, Northwestern University

  Abstract: TBA

  Zoom: TBA

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Tuesday, November 19, 2024 at 11:15 AM - 12:15 PM

  LOCATION M416, Technological Institute    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Dec

  3

  Appl Math: Evelyn Tang on "Title TBA"

  McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  11:15 AM M416, Technological Institute

  EVENT DETAILS

  Title: TBA

  Speaker: Evelyn Tang, Rice University

  Abstract: TBA

  Zoom: TBA

  -----

  To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

  add esam-seminar Youremail Firstname Lastname

  more less

  TIME Tuesday, December 3, 2024 at 11:15 AM - 12:15 PM

  LOCATION M416, Technological Institute    map it

  ADD TO CALENDAR

  CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

  CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

• Dec

  7

  Fall classes end

  University Academic Calendar

  All Day

  EVENT DETAILS

  Fall classes end

  more less

  TIME Saturday, December 7, 2024

  ADD TO CALENDAR

  CONTACT Office of the Registrar    nu-registrar@northwestern.edu EMAIL

  CALENDAR University Academic Calendar