IFISC Seminar on Wednesday Mar 23, 2022 at 14:30
Place: IFISC Seminar Room
Title: Using random matrix theory to determine the stability of the generalised Lotka-Volterra equations
Speaker: Joseph Baron, IFISC
Abstract:
<p>The generalised Lotka-Volterra equations (GLVEs) are a widely-used modelling tool in theoretical ecology, and a prominent example of a disordered system. The GLVEs model the time evolution of species abundances in a large ecosystem. The interactions coefficients are drawn from a joint probability distribution and fixed throughout the dynamics. When we integrate the GLVEs forwards in time from some initial condition, some of the original pool of species will go extinct and some will survive. The stability of the resulting surviving community of species has been successfully deduced using Dynamic Mean-Field Theory (DMFT) previously.&nbsp;<br />
<br />
In this talk, we use DMFT to examine the statistics of the interactions between the species in the surviving community, which differ from those of the original pool of species. Using random matrix theory, we then show how the specifics of these interaction statistics affect the stability. In particular, we show that the full non-Gaussian nature of these statistics has to be taken into account in order to correctly predict stability. This is in contrast to the universality principle of random matrix theory, which suggests that the eigenvalues of a random matrix can be deduced from only the first and second moments and correlations of its elements. We discuss the implications of our findings both for random matrix theory and for theoretical ecology.<br />
<br />
https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09</p>
Url event:https://ifisc.uib-csic.es/en/events/seminars/using-random-matrix-theory-to-determine-the-stabil/
IFISC Seminar on Wednesday Mar 23, 2022 at 14:30
Place: Zoom Seminar
Title: Using random matrix theory to determine the stability of the generalised Lotka-Volterra equations
Speaker: Joseph Baron, IFISC
Abstract:
<p>The generalised Lotka-Volterra equations (GLVEs) are a widely-used modelling tool in theoretical ecology, and a prominent example of a disordered system. The GLVEs model the time evolution of species abundances in a large ecosystem. The interactions coefficients are drawn from a joint probability distribution and fixed throughout the dynamics. When we integrate the GLVEs forwards in time from some initial condition, some of the original pool of species will go extinct and some will survive. The stability of the resulting surviving community of species has been successfully deduced using Dynamic Mean-Field Theory (DMFT) previously.&nbsp;<br />
<br />
In this talk, we use DMFT to examine the statistics of the interactions between the species in the surviving community, which differ from those of the original pool of species. Using random matrix theory, we then show how the specifics of these interaction statistics affect the stability. In particular, we show that the full non-Gaussian nature of these statistics has to be taken into account in order to correctly predict stability. This is in contrast to the universality principle of random matrix theory, which suggests that the eigenvalues of a random matrix can be deduced from only the first and second moments and correlations of its elements. We discuss the implications of our findings both for random matrix theory and for theoretical ecology.<br />
<br />
https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09</p>
Url event:https://ifisc.uib-csic.es/en/events/seminars/using-random-matrix-theory-to-determine-the-stabil/
Dear All.
Just to avoid confusion: An IFISC seminar had originally been announced for next Wednesday, 16th March. However, at the request of the speaker, we had to postpone the talk (new date to be decided). The request came too late for us to fill the slot, so unless a volunteer comes forward in the next few days, there will be no seminar this week.
Please accept our apologies.
Tobias & Sandro
Tobias Galla
Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC)
tobias.galla(a)ifisc.uib-csic.es
@tobiasgalla
Webinar organizado por Institute of Physics (IOP) e IFISC con varios
participantes y mesa redonda.
Complex Systems Approaches to Information Processing
https://physicsworld.com/a/complex-systems-approaches-to-information-proces…
Martes 8 de Marzo 15h (CET)
Se necesita registrarse previamente
https://register.gotowebinar.com/register/8529868692589874188
--
*****************************************************************
Maxi San Miguel
IFISC (CSIC-UIB)
Instituto de Física Interdisciplinar y Sistemas Complejos
Campus Universitat Illes Balears
E-07122 Palma de Mallorca, Spain
http://ifisc.uib-csic.es/maxi
Tel. +34-971-173229; Fax: +34-971-173248
email: maxi(a)ifisc.uib-csic.es
*****************************************************************
IFISC Seminar on Tuesday Mar 08, 2022 at 15:00
Place: Zoom Seminar
Title: IOP webinar on special issue `Complex Systems Approaches to Information Processing' in JPhys Complexity
Speaker: M. San Miguel, C. Mirasso, I. Fischer, K. Wiesner, Hiba Sheheitli, Marc Timme, Daniel Gauthier, Roberta Zambrini, Speakers will be from a number of institutions locally and internationally
Abstract:
<p>Webinar co-organized by IOP and IFISC during this week</p>
<p><a href="https://physicsworld.com/a/complex-systems-approaches-to-informa…
<p>Please note that you need to register for this event beforehand:</p>
<p><a href="https://register.gotowebinar.com/register/8529868692589874188&qu…
Url event:https://ifisc.uib-csic.es/en/events/seminars/iop-webinar-on-special-issue-complex-systems-appro/
IFISC Seminar on Tuesday Mar 08, 2022 at 15:00
Place: Zoom Seminar
Title: IOP webinar on special issue `Complex Systems Approaches to Information Processing' in JPhys Complexity
Speaker: M. San Miguel, C. Mirasso, I. Fischer, K. Wiesner, Hiba Sheheitli, Marc Timme, Daniel Gauthier, Roberta Zambrini, Speakers will be from a number of institutions locally and internationally
Abstract:
<p>Webinar co-organized by IOP and IFISC during this week</p>
<p><a href="https://physicsworld.com/a/complex-systems-approaches-to-informa…
<p>Please note that you need to register for this event beforehand:</p>
<p><a href="https://register.gotowebinar.com/register/8529868692589874188&qu…
Url event:https://ifisc.uib-csic.es/en/events/seminars/iop-webinar-on-special-issue-complex-systems-appro/
IFISC Seminar on Wednesday Mar 02, 2022 at 14:30
Place: Zoom Seminar
Title: Benchmarking experimental quantum computation: rigorous noise analysis in the simulation of dissipative collective effects
Speaker: Marco Cattaneo, IFISC and University of Helsinki
Abstract:
<p>&nbsp;In the era of near-term quantum computers, understanding the features of noise in quantum devices is essential to benchmark and improve the accuracy of quantum simulation algorithms. Here, we present an in-depth comparison between the results of a rigorous noise analysis of a near-term quantum computer and the outcomes of the &nbsp;first fully quantum experimental simulation of dissipative collective effects, the relevance of which ranges from the study of entanglement in biological systems to the engineering of dissipative phase transitions and quantum synchronization. We show that the conclusions drawn from the noise analysis crucially improve our understanding of the dynamics we are actually implementing on the quantum computer, and that the widely employed randomized benchmarking procedure may not always be reliable to detect faulty gates in the algorithm.</p>
<p>Zoom:&nbsp;<a href="https://us02web.zoom.us/j/83829318876?pwd=Z2pqbUtIMEV3NUQvU0hpakp0NGtsUT09">https://us02web.zoom.us/j/83829318876?pwd=Z2pqbUtIMEV3NUQvU0hpakp0NGtsUT09</a></p>
Url event:https://ifisc.uib-csic.es/en/events/seminars/benchmarking-experimental-quantum-computation-rigo/