THE PHYSICS GRADUATE PROGRAM invites everyone to the seminar:

Stochastic oscillations, power law avalanches and dragon kings in quasi-critical systems

Prof. Dr. Osame Kinouchi
Departamento de Física – FFCLRP – USP

Abstract:

In the last decade, several models with network adaptive mechanisms (link deletion-creation, dynamic synapses, dynamic gains) have been proposed as examples of self-organized criticality (SOC) to explain neuronal avalanches. However, all these systems present stochastic oscillations hovering around the critical region that are incompatible with standard SOC and has been called self-organized quasi-criticality (SOqC). Here we make a linear stability analysis of the mean field fixed points of a SOqC model of discrete time stochastic spiking neurons. Firing rate adaptation, produced by dynamic neuronal gains, tunes the system toward the critical region. We find that the fixed points correspond to barely stable spirals that turn out indifferent at criticality where a Neimark-Sacker bifurcation occurs. This near indifference means that finite-size fluctuations can excite stochastic oscillations and avalanches, producing a mechanism for the emergence of dragon king events. The coexistence of these different types of neuronal activity is an experimental prediction that differs from standard SOC models.

Date: September 18, 2018 – (friday) – Place: Sala 212 – Auditório do Departamento de Física – Time: 10:15 a.m.

The Physics Graduate Program invites everyone to:

Qualifying Examination for Doctoral Thesis

Igor Dornelles Schoeller Siciliani

Aplicações de Mecânica Estatística em Econofísica, Mineração de Textos e Neurociência

Defense Committee:

Prof. Dr. Marcelo Henrique Romano Tragtenberg – (president) – UFSC/FSC
Prof. Dr. Osame Kinouchi Filho – (external member) – USP
Prof. Dr. Lucas Nicolao – (local member) – UFSC/FSC
Prof. Dr. Eraldo Sérgio Barobosa da Silva – (local member) – UFSC/CMN

Date: September 13, 2018 – thursday – Time: 2 p.m. – Place: Auditório Airton Silva – (piso térreo do Departamento de Matemática)

The Physics Graduate Program invites everyone to:

Defence of M.Sc. dissertation

Thomas Zerrenner Flórido

ANALYSIS OF EMISSION LINES IN GALAXIES: THE DIFFUSED IONIZED GAS IN MaNGA

Defense Commitee

Profª. Drª. Natalia Vale Asari – (president) – UFSC/FSC
Prof. Dr. Rogemar André Riffel – (external member) – UFSM
Prof. Dr. Abilio Mateus Junior – (local member) – UFSC/FSC

Date: September 12, 2018 – wednesday – Time: 2:00 p.m. – Place: Sala 202 – Departamento de Matemática