July 2022 - semfis - Mailing lists@ IFISC

Talk on Tuesday, Jul 19, 2022 at 12:00
by semfis＠ifisc.uib-csic.es 15 Jul '22

15 Jul '22

Talk on Tuesday Jul 19, 2022 at 12:00 Place: IFISC Seminar Room Title: Modelling parasite-produced marine diseases of immobile hosts Speaker: Alex Giménez Romero, IFISC Abstract: Parasite-produced marine infectious diseases pose a substantial threat to marine ecosystems and the conservation of their biodiversity. The state of the art of epidemiological studies in marine ecosystems lags behind that of their terrestrial counterparts, and only recently some none-spatial compartmental models have been proposed to describe this kind of epidemics. Furthermore, in realistic situations, epidemic transmission is conditioned by the spatial distribution of hosts, the parasites mobility patterns and the inherent stochasticity of the epidemic process. Here we developed a compartmental model for parasite-induced marine diseases of immobile hosts. First, we study in depth the non spatial version of the model based on a system of ODE&rsquo;s, finding some conserved quantities of the model and some exact and approximate reductions. Then, we study the spatially-explicit version based on an individual-based model to investigate the impact of spatial disease transmission compared to the non-spatial counterpart. Presential in seminar room, with parallel Zoom stream at&nbsp;https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/modelling-parasite-produced-marine-diseases-of-imm/

1 0

IFISC Seminar on Wednesday, Jul 20, 2022 at 14:30
by semfis＠ifisc.uib-csic.es 15 Jul '22

15 Jul '22

IFISC Seminar on Wednesday Jul 20, 2022 at 14:30 Place: IFISC Seminar Room Title: Type-I excitable media: a theoretical framework for space extended excitable systems Speaker: Pablo Moreno Spiegelberg, IFISC Abstract: Excitability is a property of certain nonlinear dynamical systems concerning their response to external perturbations. Excitable systems can be classified into two classes, Type-I and II, with different dynamical properties and caused by different bifurcations. Excitable media, locally excitable spatial extended systems, show different regimes in which local perturbation exceeding a threshold can propagate across the medium. There are many studies considering Type-II excitable media, but much less is known about pulse propagation in the Type-I case. Recently, several vegetation systems compatible with Type-I excitability have shown traveling pulses, renewing interest in their study. In this seminar we will show the differences between both types of excitable media and characterize the properties of Type-I excitable pulses. Presential in seminar room, with parallel Zoom stream at&nbsp;https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/type-i-excitable-media-a-theoretical-framework-for/

1 0

Reminder: IFISC Seminar, TODAY - Wednesday, Jul 13, 2022 at 14:30
by semfis＠ifisc.uib-csic.es 13 Jul '22

13 Jul '22

IFISC Seminar on Wednesday Jul 13, 2022 at 14:30 Place: IFISC Seminar Room Title: Competition and cooperation in contagion processes on complex networks Speaker: Byungjoon Min, Chungbuk National University Abstract: How to predict and control contagion processes on networked systems is an important problem of much interest. Recently, we introduced competition and cooperation in various ways to the classical contagion model and analyzed them. Here we present key results of our attempts. First, we found that double phase transitions and hysteresis can occur when simple and complex contagions compete with each other in networks. Second, we analyzed cooperative epidemics at the individual node level through the message-passing method when two pathogens cooperatively spread. We also discuss the cooperative spreading on multi-layered networks, showing discontinuous transitions and hysteresis. &nbsp; Presential seminar in the seminar room, with parallel Zoom stream at&nbsp;https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/competition-and-cooperation-in-contagion-processes/

1 0

Reminder: Talk, TODAY - Tuesday, Jul 12, 2022 at 12:00
by semfis＠ifisc.uib-csic.es 12 Jul '22

12 Jul '22

Talk on Tuesday Jul 12, 2022 at 12:00 Place: Zoom Seminar Title: Quantum associative memory with a single driven-dissipative non-linear oscillator Speaker: Adrià Labay Mora, IFISC Abstract: Topic: MdM Quantum Meeting Place: IFISC Seminar Room / Zoom Join Zoom Meeting https://uibuniversitat.zoom.us/j/95008734687 Abstract: Algorithms for associative memory typically rely on a network of many connected units. The prototypical example is the Hopfield model, whose generalizations to the quantum realm are mainly based on open quantum Ising models. We propose a realization of associative memory with a single driven-dissipative quantum oscillator exploiting its infinite degrees of freedom in phase space. The model can improve the storage capacity of discrete neuron-based systems in a large regime and we prove successful state discrimination between n coherent states, which represent the stored patterns of the system. These can be tuned continuously by modifying the driving strength, constituting a modified learning rule. We show that the associative-memory capacity is inherently related to the existence of a spectral gap in the Liouvillian superoperator, which results in a large timescale separation in the dynamics corresponding to a metastable phase. Url event:https://ifisc.uib-csic.es/en/events/seminars/quantum-associative-memory-with-a-single-driven-di/

1 0

Talk on Tuesday, Jul 12, 2022 at 12:00
by semfis＠ifisc.uib-csic.es 10 Jul '22

10 Jul '22

Talk on Tuesday Jul 12, 2022 at 12:00 Place: Zoom Seminar Title: Quantum associative memory with a single driven-dissipative non-linear oscillator Speaker: Adrià Labay Mora, IFISC Abstract: Topic: MdM Quantum Meeting Place: IFISC Seminar Room / Zoom Join Zoom Meeting https://uibuniversitat.zoom.us/j/95008734687 Abstract: Algorithms for associative memory typically rely on a network of many connected units. The prototypical example is the Hopfield model, whose generalizations to the quantum realm are mainly based on open quantum Ising models. We propose a realization of associative memory with a single driven-dissipative quantum oscillator exploiting its infinite degrees of freedom in phase space. The model can improve the storage capacity of discrete neuron-based systems in a large regime and we prove successful state discrimination between n coherent states, which represent the stored patterns of the system. These can be tuned continuously by modifying the driving strength, constituting a modified learning rule. We show that the associative-memory capacity is inherently related to the existence of a spectral gap in the Liouvillian superoperator, which results in a large timescale separation in the dynamics corresponding to a metastable phase. Url event:https://ifisc.uib-csic.es/en/events/seminars/quantum-associative-memory-with-a-single-driven-di/

1 0

IFISC Seminar on Wednesday, Jul 13, 2022 at 14:30
by semfis＠ifisc.uib-csic.es 08 Jul '22

08 Jul '22

IFISC Seminar on Wednesday Jul 13, 2022 at 14:30 Place: IFISC Seminar Room Title: Competition and cooperation in contagion processes on complex networks Speaker: Byungjoon Min, Chungbuk National University Abstract: How to predict and control contagion processes on networked systems is an important problem of much interest. Recently, we introduced competition and cooperation in various ways to the classical contagion model and analyzed them. Here we present key results of our attempts. First, we found that double phase transitions and hysteresis can occur when simple and complex contagions compete with each other in networks. Second, we analyzed cooperative epidemics at the individual node level through the message-passing method when two pathogens cooperatively spread. We also discuss the cooperative spreading on multi-layered networks, showing discontinuous transitions and hysteresis. &nbsp; Presential seminar in the seminar room, with parallel Zoom stream at&nbsp;https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/competition-and-cooperation-in-contagion-processes/

1 0

Reminder: Talk, TODAY - Thursday, Jul 07, 2022 at 12:00
by semfis＠ifisc.uib-csic.es 07 Jul '22

07 Jul '22

Talk on Thursday Jul 07, 2022 at 12:00 Place: Zoom Seminar Title: Periodically Refreshed Baths: a numerical technique and a thermodynamic cycle Speaker: Archak Purkayastha, Trinity College Dublin Abstract: Topic: MdM Quantum Meeting Time: Jul 7, 2022 12:00 AM Mallorca Join Zoom Meeting <a href="https://uibuniversitat.zoom.us/j/92630576806" target="_blank">https://uibuniversitat.zoom.us/j/92630576806</a> &nbsp; Abstract: In this talk, I will introduce the Periodically Refreshed Baths (PReB) scheme. Simulating non-Markovian dynamics of interacting quantum many-body systems strongly coupled to multiple baths at different temperatures and chemical potentials is a challenging and experimentally relevant problem. The PReB scheme allows for efficient tensor network based numerical simulation of such situations much beyond what is possible in most other techniques. Going further, one can extend the PReB scheme beyond just a numerical technique, to a dynamical process that can be potentially realized in experiments. We then explore the thermodynamics of the steady state of the PReB process. This leads to novel Periodically Refreshed Quantum Thermal Machines, which can interpolate between autonomous quantum thermal machines and those based on collisional or repeated interactions with single-site environments. These quantum thermal machines work on a single-stroke thermodynamic cycle where the workin g material is always out-of-equilibrium. They can have many counter-intuitive properties, which I will demonstrate via a simple example. Refs: Phys. Rev. B 104, 045417 (2021), &nbsp;arXiv:2202.05264 (2022). Url event:https://ifisc.uib-csic.es/en/events/seminars/periodically-refreshed-baths-a-numerical-technique/

1 0

Talk on Thursday, Jul 07, 2022 at 12:00
by semfis＠ifisc.uib-csic.es 04 Jul '22

04 Jul '22

Talk on Thursday Jul 07, 2022 at 12:00 Place: Zoom Seminar Title: Periodically Refreshed Baths: a numerical technique and a thermodynamic cycle Speaker: Archak Purkayastha, Trinity College Dublin Abstract: Topic: MdM Quantum Meeting Time: Jul 7, 2022 12:00 AM Mallorca Join Zoom Meeting <a href="https://uibuniversitat.zoom.us/j/92630576806" target="_blank">https://uibuniversitat.zoom.us/j/92630576806</a> &nbsp; Abstract: In this talk, I will introduce the Periodically Refreshed Baths (PReB) scheme. Simulating non-Markovian dynamics of interacting quantum many-body systems strongly coupled to multiple baths at different temperatures and chemical potentials is a challenging and experimentally relevant problem. The PReB scheme allows for efficient tensor network based numerical simulation of such situations much beyond what is possible in most other techniques. Going further, one can extend the PReB scheme beyond just a numerical technique, to a dynamical process that can be potentially realized in experiments. We then explore the thermodynamics of the steady state of the PReB process. This leads to novel Periodically Refreshed Quantum Thermal Machines, which can interpolate between autonomous quantum thermal machines and those based on collisional or repeated interactions with single-site environments. These quantum thermal machines work on a single-stroke thermodynamic cycle where the workin &nbsp;g material is always out-of-equilibrium. They can have many counter-intuitive properties, which I will demonstrate via a simple example. Refs: Phys. Rev. B <a href="callto:104, 045417 (2021" onclick="window.top.Com_Zimbra_Phone.unsetOnbeforeunload()">104, 045417 (2021</a>), &nbsp;arXiv:<a href="callto:2202.05264 (2022" onclick="window.top.Com_Zimbra_Phone.unsetOnbeforeunload()">2202.05264 (2022</a>). Url event:https://ifisc.uib-csic.es/en/events/seminars/periodically-refreshed-baths-a-numerical-technique/

1 0