June 2021 - Materia-seminarios

Seminar: Overfitting mitigation in correlation matrices and applications to the study of brain connectivity.
by Daniel Manzano 25 Jun '21

25 Jun '21

El grupo de Física Estadística de los sistemas Complejos les invita al siguiente seminario (online y presencial): Speaker: Dr. Miguel Ibáñez, ISTC-CNR (Italy). Title: Overfitting mitigation in correlation matrices and applications to the study of brain connectivity Abstract: We compare various known and original strategies of overfitting mitigation in correlation matrices, in the context of brain functional connectivity. In particular, we infer a database of human brain activity from functional Magnetic Resonance Imaging (fMRI), beyond Maximum Likelihood inference and using the multivariate Gaussian as likelihood. We show that the relative algorithm performances are consistent across subjects, and across samples of a synthetic database of similar characteristics. We observe as well that the resulting cleaned correlation matrices, that are proposed as a refined model of functional connectivity, depend crucially on the cleaning algorithm. We discuss possible applications of these findings to network neuroscience. Date ant time: Monday, June 28th, 12:00. Place: Aula de ordenadores del Área de Física de la Materia (hasta completar aforo). Online: https://meet.google.com/ijd-agcd-rye <https://meet.google.com/ijd-agcd-rye> Atentamente, --------------------------------------------------------------------------------- Daniel Manzano Electromagnetism and Condensed Matter Department Institute “Carlos I” for Theoretical and Computational Physics University of Granada Facultad de Ciencias, Av. Fuentenueva s/n Granada 18071, Spain Phone: +34 958241000 Ext: 20569 http://ic1.ugr.es/manzano/ <http://ic1.ugr.es/manzano/>

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Recordatorio de seminario: Macroscopically nonlocal quantum correlations.
by Daniel Manzano 10 Jun '21

10 Jun '21

El Grupo de Física Estadística de los sistemas Complejos les invita al siguiente seminario, que se realizará de manera presencial y online. Speaker: Miguel Gallego Ballester. University of Vienna. Title: Macroscopically nonlocal quantum correlations. Abstract: It is usually believed that coarse-graining of quantum correlations leads to classical correlations in the macroscopic limit. Such a principle, known as macroscopic locality, has been proved for correlations arising from independent and identically distributed (IID) entangled pairs. In this work we consider the generic (non-IID) scenario. We find that the Hilbert space structure of quantum theory can be preserved in the macroscopic limit. This leads directly to a Bell violation for coarse-grained collective measurements, thus breaking the principle of macroscopic locality. Reference: https://arxiv.org/abs/2104.03988#:~:text=It%20is%20usually%20believed%20tha… <https://arxiv.org/abs/2104.03988#:~:text=It%20is%20usually%20believed%20tha…> Date and time: Friday, June 11th. 10:00. Place: Aula de ordenadores del Área de Física de la Materia and in Google Meet: https://meet.google.com/bqi-vemu-gro <https://meet.google.com/bqi-vemu-gro> --------------------------------------------------------------------------------- Daniel Manzano Electromagnetism and Condensed Matter Department Institute “Carlos I” for Theoretical and Computational Physics University of Granada Facultad de Ciencias, Av. Fuentenueva s/n Granada 18071, Spain Phone: +34 958241000 Ext: 20569 http://ic1.ugr.es/manzano/ <http://ic1.ugr.es/manzano/>

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Seminario (presencial y online): Macroscopically nonlocal quantum correlations.
by Daniel Manzano 07 Jun '21

07 Jun '21

El Grupo de Física Estadística de los sistemas Complejos les invita al siguiente seminario, que se realizará de manera presencial y online. Speaker: Miguel Gallego Ballester. University of Vienna. Title: Macroscopically nonlocal quantum correlations. Abstract: It is usually believed that coarse-graining of quantum correlations leads to classical correlations in the macroscopic limit. Such a principle, known as macroscopic locality, has been proved for correlations arising from independent and identically distributed (IID) entangled pairs. In this work we consider the generic (non-IID) scenario. We find that the Hilbert space structure of quantum theory can be preserved in the macroscopic limit. This leads directly to a Bell violation for coarse-grained collective measurements, thus breaking the principle of macroscopic locality. Reference: https://arxiv.org/abs/2104.03988#:~:text=It%20is%20usually%20believed%20tha… <https://arxiv.org/abs/2104.03988#:~:text=It%20is%20usually%20believed%20tha…> Fecha y hora: Viernes 11 de Junio a las 10:00. Lugar: Aula de ordenadores del Área de Física de la Materia (hasta completar aforo) y vía Google Meet: https://meet.google.com/bqi-vemu-gro <https://meet.google.com/bqi-vemu-gro> --------------------------------------------------------------------------------- Daniel Manzano Electromagnetism and Condensed Matter Department Institute “Carlos I” for Theoretical and Computational Physics University of Granada Facultad de Ciencias, Av. Fuentenueva s/n Granada 18071, Spain Phone: +34 958241000 Ext: 20569 http://ic1.ugr.es/manzano/ <http://ic1.ugr.es/manzano/>

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