Junior Strings is a seminar series where DPhil students present topics of common interest that do not necessarily overlap with their own research area. This is primarily aimed at PhD students and post-docs but everyone is welcome.
Note: we would recommend to join the meeting using the Zoom client for best user experience.
Dr. Sonia Kéfi is a Research Director at the the Evolution Sciences Institute (ISEM) in Montpellier, France (https://biodicee.edu.umontpellier.fr/who-we-are/sonia-kefi/).
She is also an external professor at the Santa Fe Institute and she was the recipient of the 2020 Erdos-Renyi Prize from the Network Science Society. Her research aims at understanding how ecosystems persist and change under pressure from changing climate and land use. In her works, she combines mathematical modeling and data analysis to investigate the role of ecological interactions in stabilizing and destabilizing ecosystems, as well as to develop indicators of resilience that could warn us of approaching ecosystem shifts.
Understanding the stability of ecological communities is a matter of increasing importance in the context of global environmental change. Yet it has proved to be a challenging task. Different metrics are used to assess the stability of ecological systems, and the choice of one metric over another may result in conflicting conclusions. While the need to consider this multitude of stability metrics has been clearly stated in the ecological literature for decades, little is known about how different stability metrics relate to each other. I’ll present results of dynamical simulations of ecological communities investigating the correlations between frequently used stability metrics, and I will discuss how these results may contribute to make progress in the quantification of stability in theory and in practice.
Zoom Link: https://zoom.us/j/93174968155?pwd=TUJ3WVl1UGNMV0FxQTJQMFY0cjJNdz09
Meeting ID: 931 7496 8155
Passcode: 502784
I will explain an ongoing program, joint with Kari Vilonen, that aims to study unitary representations of real reductive Lie groups using mixed Hodge modules on flag varieties. The program revolves around a conjecture of Schmid and Vilonen that natural filtrations coming from the geometry of flag varieties control the signatures of Hermitian forms on real group representations. This conjecture is expected to facilitate new progress on the decades-old problem of determining the set of unitary irreducible representations by placing it in a more conceptual context. Our results to date centre around the interaction of Hodge theory with the unitarity algorithm of Adams, van Leeuwen, Trapa, and Vogan, which calculates the signature of a canonical Hermitian form on an arbitrary representation by reducing to the case of tempered representations using deformations and wall crossing. Our results include a Hodge-theoretic proof of the ALTV wall crossing formula as a consequence of a more refined result and a verification of the Schmid-Vilonen conjecture for tempered representations.
The course will serve as an introduction to the theory of multivalued Dir-minimizing functions, which can be viewed as harmonic functions which attain multiple values at each point.
Aimed at Postgraduate students interested in geometric measure theory and its link with elliptic PDEs, a solid knowledge of functional analysis and Sobolev spaces, acquaintance with variational
methods in PDEs and some basic geometric measure theory are recommended.
Sessions led by Dr Immanuel Ben Porat will take place on
09 May 2023 15:30 - 17:30 C4
16 May 2023 15:30 - 17:30 C4
23 May 2023 15:30 - 17:30 C4
30 May 2023 15:30 - 17:30 C4
Should you be interested in taking part in the course, please send an email to @email.
The space of unordered tuples. The notion of differentiability and the theory of metric Sobolev in the context of multi-valued functions. Multivalued maximum principle and Holder regularity. Estimates on the Hausdorff dimension of the singular set of Dir-minimizing functions. If time permits: mass minimizing currents and their link with Dir-minimizers.
The course will serve as an introduction to the theory of multivalued Dir-minimizing functions, which can be viewed as harmonic functions which attain multiple values at each point.
Aimed at Postgraduate students interested in geometric measure theory and its link with elliptic PDEs, a solid knowledge of functional analysis and Sobolev spaces, acquaintance with variational
methods in PDEs and some basic geometric measure theory are recommended.
Sessions led by Dr Immanuel Ben Porat will take place on
09 May 2023 15:30 - 17:30 C4
16 May 2023 15:30 - 17:30 C4
23 May 2023 15:30 - 17:30 C4
30 May 2023 15:30 - 17:30 C4
Should you be interested in taking part in the course, please send an email to @email.
The space of unordered tuples. The notion of differentiability and the theory of metric Sobolev in the context of multi-valued functions. Multivalued maximum principle and Holder regularity. Estimates on the Hausdorff dimension of the singular set of Dir-minimizing functions. If time permits: mass minimizing currents and their link with Dir-minimizers.
The course will serve as an introduction to the theory of multivalued Dir-minimizing functions, which can be viewed as harmonic functions which attain multiple values at each point.
Aimed at Postgraduate students interested in geometric measure theory and its link with elliptic PDEs, a solid knowledge of functional analysis and Sobolev spaces, acquaintance with variational
methods in PDEs and some basic geometric measure theory are recommended.
Sessions led by Dr Immanuel Ben Porat will take place on
09 May 2023 15:30 - 17:30 C4
16 May 2023 15:30 - 17:30 C4
23 May 2023 15:30 - 17:30 C4
30 May 2023 15:30 - 17:30 C4
Should you be interested in taking part in the course, please send an email to @email.
The space of unordered tuples. The notion of differentiability and the theory of metric Sobolev in the context of multi-valued functions. Multivalued maximum principle and Holder regularity. Estimates on the Hausdorff dimension of the singular set of Dir-minimizing functions. If time permits: mass minimizing currents and their link with Dir-minimizers.
The course will serve as an introduction to the theory of multivalued Dir-minimizing functions, which can be viewed as harmonic functions which attain multiple values at each point.
Aimed at Postgraduate students interested in geometric measure theory and its link with elliptic PDEs, a solid knowledge of functional analysis and Sobolev spaces, acquaintance with variational
methods in PDEs, and some basic geometric measure theory are recommended.
Sessions led by Dr Immanuel Ben Porat will take place on
09 May 2023 15:30 - 17:30 C4
16 May 2023 15:30 - 17:30 C4
23 May 2023 15:30 - 17:30 C4
30 May 2023 15:30 - 17:30 C4
Should you be interested in taking part in the course, please send an email to @email.
The space of unordered tuples. The notion of differentiability and the theory of metric Sobolev in the context of multi-valued functions. Multivalued maximum principle and Holder regularity. Estimates on the Hausdorff dimension of the singular set of Dir-minimizing functions. If time permits: mass minimizing currents and their link with Dir-minimizers.
Junior Strings is a seminar series where DPhil students present topics of common interest that do not necessarily overlap with their own research area. This is primarily aimed at PhD students and post-docs but everyone is welcome.
Junior Strings is a seminar series where DPhil students present topics of common interest that do not necessarily overlap with their own research area. This is primarily aimed at PhD students and post-docs but everyone is welcome.
A collection of bite-size 10-15 minute talks from current DPhil students in the Algebra group. The talks will be accessible to masters students and above.
With plenty of opportunity to chat to current students about what doing a PhD in algebra and representation theory is like!