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Anonymous (not verified) An Initial State with shear and vorticity for non-central heavy ion collisions V.K. Magas FQA, University of Barcelona vladimir@fqa.ub.edu Recent experimental and theoretical developments indicate that a strong initial angular momentum, which is present in non-central collisions, has to be taken into account for a detailed simulation of the reactions. As a consequence of this large initial angular momentum we observe not only a overall system rotation, but also a strong fluid shear in the initial state, which leads to large flow vorticity and subsequent particle polarization: a significant Λ polarization was detected and analyzed in detail in the RHIC BES program [1].

More than 15 years ago an effective string rope model was proposed [2] to construct nucleus-nucleus collision initial state for realistic 3+1D relativistic fluid dynamical models. This model reflected correctly not only the energy-momentum, but also angular momentum, conservations, initial shear flow and local vorticity [3]. On the other hand, recent developments in parton kinetic and field dominance models provide a rather different initial state configuration, more compact for non-central collisions, see for example [4], what makes us revisit the our initial state model in that direction [5].


[1] L. Adamczyk et al. (The STAR Collaboration), Nature 548 (2017) 62.
[2] V.K. Magas, L.P. Csernai, D.D. Strottman, Phys. Rev. C64 (2001) 014901; Nucl. Phys. A712 (2002) 167.
[3] L.P. Csernai, V.K. Magas, D.J. Wang, Phys. Rev. C87 (2013) 034906.
[4] L.G. Pang, H. Petersen, G.Y. Qin, V. Roy and X.N. Wang, Nucl. Phys. A956 (2016) 272.
[5] V.K. Magas, J. Gordillo, D.D. Strottman, Y.L. Xie and L.P. Csernai, Phys. Rev. C97 (2018) no.6, 064903.
Anonymous (not verified) cosmology with massive neutrinos David Valcin ICCUB d.valcin@icc.ub.edu Massive neutrinos are a realy good probe of the beyond standard model physics. Cosmology is a valuable asset to measure or constrain their absolute mass. Before you take advantage of the information provided by this new physics, we need to rethink the current state of analysis to include massive neutrinos.
Anonymous (not verified) Gaia as the Storyteller of the star formation history of the Milky Way disc Roger Mor Dept. Física Quàntica i Astrofísica, Institut de Ciències del Cosmos, Universitat de Barcelona (IEEC-UB), Martí Franquès 1, E080 rmor@fqa.ub.edu We developed a new theoretical framework, the Besançon Galaxy Model Fast Approximate Simulations (BGM FASt), that combined with approximate Bayesian computation techniques allows us to address fundamental questions of the Galactic structure and evolution performing multi-parameter inference. Here we use Gaia DR2 magnitudes, colours and parallaxes for stars with G<12 to explore a 15-dimensional space that includes simultaneously the stellar initial mass function (IMF) and a non-parametric star formation history (SFH) for the Milky Way disc. We find in Gaia DR2 data an imprint of a star formation burst in the Galactic thin disc region 2-3 Gyr ago and a present SFR of 1Msun/yr. Our results show a decreasing trend of the star formation rate (SFR) from 10 Gyr to about 6 Gyr ago that is consistent with the behaviour of the cosmological star formation quenching. This decreasing trend is followed by a SFR enhancement detected during a period from 5 Gyr to 1 Gyr ago. We estimate, from our best fit model, that about the 50% of the stellar mass of the Galactic thin disc was formed during this period. The timescale and the amount of stellar mass generated during the SFR enhancement event leads us to hypothesise that its origin is not intrinsic to the disc and that an external perturbation would be needed for its explanation.
Anonymous (not verified) Gaia data triggers the need for complex warp kinematic models Merce Romero-Gomez ICCUB-IEEC mromero@fqa.ub.edu In this talk we show the results from analyzing the kinematics of two different populations extracted from the Gaia Data Release 2, namely a young bright sample mainly formed by OB stars and another from the Red Giant Branch stars. We use two different, but complementary methods based on the Gaia observables, positions and proper motions, to extract the space and kinematic characteristics of the Galactic warp. We also relate our results with the ones from other related works on the Galactic warp found in the literature that use Gaia Data Release 2 data.
Anonymous (not verified) Gravitational waves and fundamental physics Roberto Emparan ICREA+ICCUB emparan@ub.edu I will present an overview of what we can learn about fundamental physics from upcoming observations of gravitational waves
Anonymous (not verified) Hunting massive relic galaxies Anna Ferré-Mateu ICCUB aferremateu@icc.ub.edu It is assumed that massive galaxies grow in a two-phase formation mode, where a superdense compact massive core is formed very rapidly and violently up to z~2 (red nugget) and then it grows in size by adding material at its outskirts via merging events, becoming the large elliptical galaxies we see nowadays. However, because mergers are stochastic events, some of these red nuggets managed to skip the second phase of formation. Dubbed as massive relic galaxies, they have remained like frozen in time since z~2 and thus constitute a direct window into the properties of the early epochs of the Universe. However, their predicted number are scarce (0.01% of today's population) and only a handful of them have been confirmed to date.
In this talk I will summarise the quest to find these elusive relic galaxies and will explore the intriguing properties they show.
Anonymous (not verified) Modeling dark matter halo substructure with the CUSP formalism. Ignacio Botella Lasaga UB nachobotella@ub.edu The ConflUent System of Peak trajectories (CUSP) is a rigorous analytic formalism allowing one to accurately recover the typical structural and kinematic properties of DM halos in hierarchical cosmologies. This is done by monitoring the ellipsoidal collapse and virialization (through shell-crossing) of their seeds, i.e. peaks in the initial Gaussian random field of density perturbations. In this talk I will show that CUSP also allows one to model halo substructure. Specifically, taking into account the statistics of peaks nested within other peaks, one can derive the properties of subhalos accreted onto halos and, by monitoring their tidal stripping by the halo potential well, one can reproduce the abundance and spatial distribution of stripped subhalos. In this way we recover the observed trends of halo substructure found in simulations and reveal the origin of the three conditions shown by Han et al. (2016) to explain such trends.
Anonymous (not verified) New involvement of ICCUB in international collaborations D. Gascon, J. Portell ICCUB dgascon@fqa.ub.edu The ICCUB has recently joined international collaborations as Virgo, IAXO and HERD. We will introduce the projects and we will describe the technological contributions of the ICCUB.
Anonymous (not verified) On robust aspects of the out-of-equilibrium dynamics Luca Tagliacozzo ICCUB luca.tagliacozzo@fqa.ub.edu In this talk I will discuss about the possible existence of robust phenomena out-of-equilibrium and the design of approximate methods able to unveil them in the context of 1D quantum-many-body systems.

Anonymous (not verified) Photons, neutrinos and cosmic rays from AGNs Matteo Cerruti ICCUB matteo.cerruti@icc.ub.edu The origin of ultra-high-energy cosmic-rays remains one of the most important open questions in astrophysics. Active galactic nuclei (AGNs), the observational effect of accretion of matter onto super-massive black-holes, have long been considered a prime candidate for cosmic-ray acceleration. A powerful tool to investigate the sources of cosmic rays is multi-messenger astronomy: if cosmic rays are accelerated in AGNs' jets, they interact with low-energy photons producing mesons which then decay to photons, leptons and neutrinos. The joint detection of photons and neutrinos from an AGN will thus represent the fingerprint of cosmic ray acceleration in the source. On 09/22/2017, IceCube and the gamma-ray instruments Fermi-LAT and MAGIC, observed the first evidence (at the 3 sigma level) of co-production of photons and neutrinos from the AGN TXS 0506+056. For the first time, theoretical models of hadronic emission from AGNs can thus be tested on both messengers. In this talk, I will briefly introduce the detection of IceCube-170922A / TXS0506+056, and the hadronic emission models. Then I will present a review of the studies on the modeling and interpretation of this unique event, showing the capability of multi-messenger campaigns to elucidate acceleration and emission mechanisms in AGNs jets.
Anonymous (not verified) Symmetry energy : From finite nuclei to neutron stars Chiranjib Mondal ICCUB chiranjib.mondal@icc.ub.edu Symmetry energy and specially its density dependence has been a major focus of research in modern day nuclear physics.
In this talk, I will try to give a simplistic overview how it plays a significant role in determining different
quantities of finite nuclei and neutron stars.
Anonymous (not verified) Testing Dark Energy using spectroscopic galaxy surveys: BAO and RSD Hector Gil Marin ICCUB hectorgil@icc.ub.edu In this talk I will review the state-of-the-art techniques for measuring the expansion of the Universe using massive spectroscopic galaxy surveys datasets, focusing on the Baryon Acoustic Oscillation (BAO) and Redshift Space Distortion (RSD) techniques. I will also present the most relevant results from BOSS and eBOSS surveys, and the forecasts for upcoming surveys Euclid and DESI.
Anonymous (not verified) The effects of the stellar wind on the jets of high-mass microquasars Edgar Molina Universitat de Barcelona / ICCUB emolina@fqa.ub.edu High-mass microquasars (HMMQ) are X-ray binaries that host a massive star and a compact object (CO) from which jets are produced. In these systems, the stellar wind from the companion star can significantly influence the jet propagation, both because the jet has to propagate through a dense medium filled with wind material, and because the wind impact on the jet may deviate it away from the star. I will present a review on different numerical and analytical approaches performed so far in order to model the jet-wind interaction in HMMQ. I will specially focus in a semi-analytical model that we have recently developed to study the large scale effects of this interaction combined with the orbital motion, both from a hydrodynamical and a radiative point of view. To conclude, I will also mention some aspects of an ongoing work that will explore the jet-wind interaction at the binary system scale.