- Materia-seminarios

Charla
by José Miguel Palomino Cobo 09 Jun '22

09 Jun '22

Buenos días! El link de hoy es: https://meet.google.com/vjf-ztpo-voi. Ahora nos vemos!

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Link
by Álvaro Tejero 08 Jun '22

08 Jun '22

Buenos días: Os dejo el enlace de la charla que tendrá lugar a continuación. https://meet.google.com/ccd-bpgh-drm ¡Ahora nos vemos! -- Álvaro Tejero PhD Student 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 Mail: atejero(a)onsager.ugr.es, atejerophys(a)gmail.com

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Fwd: [Materia] Charlas de esta semana (8 y 9 de junio a las 11.00)
by Daniel Manzano 07 Jun '22

07 Jun '22

--------------------------------------------------------------------------------- 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/> > Begin forwarded message: > > From: Carlos Perez Espigares <cpespigares(a)onsager.ugr.es> > Subject: [Materia] Charlas de esta semana (8 y 9 de junio a las 11.00) > Date: 7. June 2022 at 10:59:44 CEST > To: materia(a)onsager.ugr.es > Cc: pietro rotondo <pietrorotondo86(a)gmail.com>, "rcd.gutierrez(a)gmail.com" <rcd.gutierrez(a)gmail.com>, alessia.annibale(a)kcl.ac.uk > > Buenas, > > El mes de junio viene cargado de charlas y actividad científica en nuestro grupo aprovechando el final de las clases. Mañana miércoles 8 de junio Pietro Rotondo, de la Universita' degli Studi di Milano hablará sobre "Universal mean field upper bound for the generalisation gap of deep neural networks". Y el jueves 9 de junio Ricardo Gutiérrez, de la Universidad Carlos III de Madrid, nos dará una charla sobre "Dynamical phase transition to localized states in the two-dimensional random walk". No dudéis en difundir estos eventos a quien le pueda interesar. > > Saludos, > Carlos. > > -- > > Ponente: Dr. Pietro Rotondo. Universita' degli Studi di Milano. > > Título: Universal mean field upper bound for the generalisation gap of deep neural networks > > Resumen: Modern deep neural networks (DNNs) represent a formidable challenge for theorists: according to the commonly accepted probabilistic framework that describes their performance, these architectures should overfit due to the huge number of parameters to train, but in practice they do not. Here we employ results from replica mean field theory to compute the generalisation gap of machine learning models with quenched features, in the teacher-student scenario and for regression problems with quadratic loss function. Notably, this framework includes the case of DNNs where the last layer is optimised given a specific realisation of the remaining weights. We show how these results – combined with ideas from statistical learning theory – provide a stringent asymptotic upper bound on the generalisation gap of fully trained DNN as a function of the size of the dataset P. In particular, in the limit of large P and Nout (where Nout is the size of the last layer) and Nout ≪ P , the generalisation gap approaches zero faster than 2Nout/P, for any choice of both architecture and teacher function. Notably, this result greatly improves existing bounds from statistical learning theory. We test our predictions on a broad range of architectures, from toy fully-connected neural networks with few hidden layers to state-of-the-art deep convolutional neural networks. > > Lugar: Aula de Física Computacional. Facultad de Ciencias. > > Fecha y hora: Miércoles 8 de junio. 11:00. > _______________________________________________ > Materia mailing list > Materia(a)onsager.ugr.es > https://onsager.ugr.es/mailman/listinfo/materia

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Seminario
by Daniel Manzano 31 May '22

31 May '22

El grupo de Física de los Sistemas Complejos les invita al siguiente seminario presencial y online. Ponente: Prof. Pedro Garrido. Universidad de Granada. Título: A ghost perturbation scheme to solve ordinary differential equations. Resumen: We propose an algebraic method to systematically approach the solution of an ordinary dif- ferential equation (ODE) with any boundary conditions. We define an extended ODE (eODE) composed of a linear generic differential operator that depends on free parameters plus an ε formal perturbation formed by the original ODE minus the same linear term. After an eODE’s formal ε expansion, we can solve order by order a hierarchy of linear ODEs. We get a sequence of functions that converge exponentially fast to the solution/s when ε = 1 and after determining the free set of parameters by minimising a distance-to-the solution function. Therefore, we get a formal expan- sion of the solution that we call Ghost Expansion that can be used as a multiscaling decomposition of the ODE’s solution. The method permits the detection of several solutions to Boundary Value Problems just by looking at the number of minima of the distance function. We present the method by its application to several cases where we discuss its properties, benefits and shortcomings and some practical algorithmic improvements on it. Lugar: Aula de Física Computacional. Facultad de Ciencias. Fecha y hora: Miércoles 1 de junio. 11:00. Enlace: https://meet.google.com/xid-qwsk-iqf <https://meet.google.com/xid-qwsk-iqf> --------------------------------------------------------------------------------- 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: A ghost perturbation scheme to solve ordinary differential equations
by Daniel Manzano 29 May '22

29 May '22

El grupo de Física de los Sistemas Complejos les invita al siguiente seminario presencial y online. Ponente: Prof. Pedro Garrido. Universidad de Granada. Título: A ghost perturbation scheme to solve ordinary differential equations. Resumen: We propose an algebraic method to systematically approach the solution of an ordinary dif- ferential equation (ODE) with any boundary conditions. We define an extended ODE (eODE) composed of a linear generic differential operator that depends on free parameters plus an ε formal perturbation formed by the original ODE minus the same linear term. After an eODE’s formal ε expansion, we can solve order by order a hierarchy of linear ODEs. We get a sequence of functions that converge exponentially fast to the solution/s when ε = 1 and after determining the free set of parameters by minimising a distance-to-the solution function. Therefore, we get a formal expan- sion of the solution that we call Ghost Expansion that can be used as a multiscaling decomposition of the ODE’s solution. The method permits the detection of several solutions to Boundary Value Problems just by looking at the number of minima of the distance function. We present the method by its application to several cases where we discuss its properties, benefits and shortcomings and some practical algorithmic improvements on it. Lugar: Aula de Física Computacional. Facultad de Ciencias. Fecha y hora: Miércoles 1 de junio. 11:00. Enlace: https://meet.google.com/xid-qwsk-iqf <https://meet.google.com/xid-qwsk-iqf>

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Seminar: Cooperation from Multiplicative Processes.
by Daniel Manzano 19 Apr '22

19 Apr '22

El grupo de ´Física Estadística de los Sistemas Complejos les invita al siguiente seminario: Título: Cooperation from Multiplicative Processes Speaker: Lorenzo Fant, ICTP, Trieste. Lugar: Seminario de Física Computacional, Planta baja del Edificio de Física, Facultad de Ciencias. Fecha y hora: Jueves 21 de Abril, 10:00. 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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Contextuality and memory cost of simulation of Majorana fermions
by Daniel Manzano 04 Apr '22

04 Apr '22

El grupo de Termodinámica y Computación cuánticas de la Universidad de Granada les invita a asistir al siguiente seminario (presencial y online). Speaker: Susane Calegari. Center for Theoretical Physics PAS (Warsaw). Title: Contextuality and memory cost of simulation of Majorana fermions Abstract: Contextuality has been reported to be a resource for quantum computation, analogous to non-locality which is a known resource for quantum communication and cryptography. We show that the presence of contextuality places new lower bounds on the memory cost for classically simulating restricted classes of quantum computation. We apply this result to the simulation of a model of quantum computation based on the braiding of Majorana fermions, namely topological quantum computation (TQC) with Ising anyons, finding a saturable lower bound in log-linear in the number of physical modes for the memory cost. TQC model lies in the intersection between two computational models: the Clifford group and the fermionic linear optics (FLO), a framework analogous to bosonic linear optics. We extend our results and prove that the lower bound in the memory required in an approximate simulation of the FLO model is quadratic in the number of physical modes. Date and Time: Wednesday 6th April. 11:00. Place: Laboratorio de Física Computacional. Primera planta del Edificio de Física. Facultad de Ciencias. Universidad de Granada. Meet Link: https://meet.google.com/thw-yaqk-uqw <https://meet.google.com/thw-yaqk-uqw>

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Seminario: Questions on non-equilibrium statistical physics
by Daniel Manzano 10 Mar '22

10 Mar '22

El grupo de Física Estadística de los Sistemas Complejos así como el grupo de Termodinámica e Información Cuántica les invita al siguiente seminario: Ponente: Christian Maes (Institute for Theoretical Physics, KU Leuven). Título: Questions on non-equilibrium statistical physics Lugar: Laboratorio de Física Estadística. Planta baja del edificio de Física. Facultad de Ciencias. Universidad de Granada. Fecha y hora: Lunes 14, 11:00. Asistencia libre hasta completar aforo. 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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ICE-7 announcement (8th Conference on Quantum Information in Spain)
by Daniel Manzano 16 Feb '22

16 Feb '22

Dear Colleagues, The eighth edition of the conference series on Quantum Information in Spain (ICE-7) will take place in Granada from 23 to 27 May 2022. ICE provides gathering for discussion to researchers working in quantum information science and technologies, covering all aspects of the field: quantum communication and cryptography, quantum computation and simulation, quantum metrology and sensing, quantum information theory, quantum thermodynamics, photonics, trapped ions and enabling technologies. The web page with some information including the list of invited speakers is available at https://personal.us.es/adan/granada_2022_ice7/index.html <https://personal.us.es/adan/granada_2022_ice7/index.html> The submission for contributions is now opened and the deadline is March 15th. Registration and accommodation are also opened. The event is open to any researcher working in the field. Looking forward to meet many of you in Granada With best regards, The local organizing committee Juani Bermejo-Vega Adán Cabello Juan José García-Ripoll Rosario González-Férez Daniel Manzano Daniel Rodríguez

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Seminario: A macroecological law describes correlations as a function of phylogenetic similarity in microbial ecosystems.
by Daniel Manzano 01 Feb '22

01 Feb '22

Fecha y hora: Viernes 4 de Febrero de 2022. 12:00. Ponente: Matteo Sireci. Universidad de Granada. Título: A macroecological law describes correlations as a function of phylogenetic similarity in microbial ecosystems. Abstract: The question of how coexistence of species is generated and maintained is as old as ecology itself. Many ecological “forces” such as competition, cooperation, demographic fluctuation, environmental fluctuation and filtering, migration, predation etc. are expected to act together in ecosystems. Disentangling the effect and intensity of each of theses forces in natural communities is the focus of present research. Thanks to a recent revolution in the availability of high quality data, natural microbial ecosystems offer an invaluable possibility to tackle this question. Here, we explore if it is possible to discriminate a dominant force at a give resolution of genetic similarity. By using both relative-abundances and metagenomic data, we reveal the presence of a new macroecological law relating correlation and phylogenetic similarity. In particular, the average correlation of species abundance fluctuation decays with phylogenetic distance from positive to null values following a stretch exponential function consistently in all empirically analyzed biomes both across communities (hosts) and in temporal data for each community. By scrutinizing different ecological models, we show that competition cannot reproduce the observed pattern. Instead, the elucidated macroecological law is explained quantitatively by the “correlated stochastic logistic model” (CSLM) pointing to environmental filtering as the dominant ecological force at this resolution level. We conclude by arguing that in order to understand interactions in microbial ecosystems one needs to abandon the concept of species and study the system from different scales, much as done in physics exploiting renormalization-group ideas. Lugar: Aula de Física Computacional. Planta baja del edificio de Física. Facultad de Ciencias. Enlace: https://meet.google.com/vub-uoiw-piz <https://meet.google.com/vub-uoiw-piz> --------------------------------------------------------------------------------- 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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