Olivefest: Astroparticle Physics Looking Forward 2017

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Now showing 1 - 20 of 35
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    4 \pi in the sky
    (2017-05) Kaloper, Nemanja
    I will talk about EFT of monodromy inflation, strong coupling effects and their implications for future searches for primordial gravity waves.
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    Astrophysical Searches for Dark Matter: A Status Report
    (2017-05) Profumo, Stefano
    I will give an update on current status and future prospects in searching for the particle nature of dark matter with astronomical and cosmic ray observations. I will discuss a few more or less controversial signals, and how they can be tested and probed.
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    Observational Constraints on the Primordial Helium Abundance
    (2017-05) Skillman, Evan
    I will review recent progress on the observational determination of the primordial helium abundance (Yp). Presently, the best constraints on Yp come from observations of star forming regions in very metal-poor galaxies (although the impact of Yp on the CMB has been detected). Progress has come through the discovery of more very metal-poor galaxies and by extending spectral observations in to the near infrared with, for example, the Large Binocular Telescope.
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    From local chemical evolution to cosmic chemical evolution
    (2017-05) Vangioni, Elisabeth
    My scientific life with Keith began about twenty five years ago with the study of the chemical evolution of light elements :cosmological elements D, He3, He4 and Li7 and spallative elements, LiBeB. Recently, major CMB results coming from WMAP and Planck, and observations of the total luminosity density leading to significant progress in establishing the star formation rate (SFR) at high redshift, led us to study in detail primordial stars say, Pop III stars, and their different properties (mass and associated nucleosynthesis, related ionizing power..), all that in a cosmological context. Presently, I will present the global cosmic chemical evolution within the framework of hierarchical formation of structures, in a merger tree context, to have a look at the early universe: reionization of the Universe, gamma ray burst and correlation with high z SFR, metal dispersion in DLAs... Finally, the discovery of gravitational waves coming from binary black holes mergers opens a new astrophysical window and we can, thanks to our nucleosynthetic approach, give some constraints on the cosmic binary compact object merger rates and associated stochastic gravitational background
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    Preferred DM Scenarios in SUSY Theories
    (2017-05) Heinemeyer, Sven
    We analyze various SUSY Theories using all available experimental data. The analyses are performed within the MasterCode collaboration. The data includes Higgs measurements and exclusion bounds, SUSY bounds from LHC searches, electroweak precision data, flavor observables, direct searches for DM and Planck data. The theories analyzed comprise GUT based scenarios such as the CMSSM, NUHM, AMSB, ... as well as low-energy realizations, e.g. the pMSSM10 or pMSSM11. We obtain the experimetally preferred parameter regions and thus the preferred DM scenarios in the various theories. Predictions where to find SUSY DM are discussed.
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    Bringing Astrophysics and Cosmology to the Particle Data Book
    (2017-05) Barnett, Michael
    For 32 years, the outstanding work of Keith Olive has brought astrophysics and cosmology (A&C) to our community through his major contributions to the Particle Data Book. He has brought A&C to the Data Listings as well as to the eight Review articles. PDG is a large collaboration of 223 authors from 148 institutions in 24 countries. During the Olive era, citations grew enormously. For the last edition, downloads of the A&C reviews totaled 137,000.
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    Gravitation: constants, a wall and some waves
    (2017-05) Uzan, Jean-Philippe
    Over the past 10 years, I had the chance to hide behind the wall of fundamental constants with Keith, trying to surprise their idle variation. Not catch I may say but it allowed our French-American team to investigate various extensions of general relativity and to test the equivalence principle during big-bang nucleosynthesis and in population III stars. Recently, we dived in the gravity wave background, opening new directions of research on gravity and astrophysics.
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    A galaxy and it's dark matter profile: a story of enhanced annihilations
    (2017-05) Sandick, Pearl
    In this talk I’ll discuss a scenario in which a spike in the dark matter density profile in the subparsec region around the supermassive black hole at the center of the Milky Way galaxy gives rise to enhanced dark matter annihilations and, consequently, to enhanced gamma-ray emissions. Bounds on these emissions can be used to constrain dark matter models. In particular, I’ll discuss the importance of modeling the spike’s history for these endeavors. Gravitational interactions of the spike with baryons can lead to the depletion of the spike radius over time, and the limits one obtains on the properties of dark matter vary profoundly depending on the depletion. I will discuss these issues in the context of generic particle physics models that allow for velocity-dependent dark matter annihilation cross sections, and also to a class of simplified dark matter models with t-channel mediators. Finally, if the properties of dark matter are known, one can place constraints on the form of the dark matter spike. I’ll present the constraints on the form of the spike under the assumption that the gamma-ray emission from the extended Galactic Center region observed by Fermi is due to dark matter annihilations.
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    Dark Matter: a Historical Perspective
    (2017-05) Srednicki, Mark
    I will review the impact of the dark matter problem on particle physics, and summarize where we stand today.
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    On a reinterpretation of the Higgs field in supersymmetry and a proposal for new quarks
    (2017-05) Munoz, Carlos
    In this talk, in the framework of supersymmetry with right-handed neutrinos we will be able to reinterpret the Higgs superfields as a fourth family of leptons. From the theoretical viewpoint, this seems to be more satisfactory than the situation in usual supersymmetric models, where the Higgses are ‘disconnected’ from the rest of the matter and they have not a three-fold replication. Inspired by this interpretation of the Higgs superfields, we also propose the possible existence of a vector-like quark doublet representation in the low-energy supersymmetric spectrum. These new quark superfields have the implication of a potentially rich phenomenology at the LHC.
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    Keith Inflated
    (2017-05) Nanopoulos, Dimitri
    A Flipped Model for “Everything” below The Planck scale is presented.It is based on No-Scale Supergravity x Flipped SU(5),both components derivable,in principle,from string theory and providing: A SU(N,1) No-Scale Inflation ,avatarized as a Starobinsky -like model ,but with distinctive differences and automatically embedded in Flipped SU(5),specific Cosmological history of the Universe that leads to Supercosmology, strong reheating,controlled entropy release,baryon asymmetry ,on the nose,through RH heavy neutrinos,neutrino masses/ mixings,in accordance with present data and stable enough protons,but reachable ,in near future,lifetime,and a LHC attainable SUSY spectrum. Appropriately enough, Keith has played a pivotal role on all the above ,who sounds like the end (???) result of 35 years group work...
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    Keith’s dark side (and some others)
    (2017-05) Ellis, John
    After some historical and personal reminiscences, I will discuss what we can learn about the possible scale of supersymmetry from the density of dark matter, and the prospects for discovering supersymmetry at the LHC, in direct searches for dark matter scattering and in experiments at future colliders.
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    Alpha-attractors and B-mode targets
    (2017-05) Kallosh, Renata
    We discuss alpha-attractor cosmological models which can be derived by a consistent reduction from theories with maximal supersymmetry, like M-theory, superstring theory, or maximal supergravity, to minimal supersymmetry models. These models provide a set of targets for the future detectors of primordial gravitational waves, scanning the region of tensor to scalar ratio between 1/100 and 1/1000.
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    Banquet Presentation
    (2017-05) Ellis, John
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    Constraints on superstrings, inflation, and extra dimensions from the CMB and big bang nucleosynthesis
    (2017-05) Mathews, Grant
    The energy scale of superstrings was obtainable iduring the early moments of chaotic inflation out of the string theory landscape. This talk explores the possibility that a specific superstring excitation may have made itself known via its coupling to the field of inflation. This may have left an imprint of “dips” in the power spectrum of temperature fluctuations in the cosmic microwave background. The identification of this particle as a superstring is possible because there may be evidence for different oscillator states of the same superstring that appear on different scales on the sky. It will be shown that from this imprint one can deduce the mass, number of oscillations, and coupling constant for the superstring. Although the evidence is marginal, this may constitute the first observation of a superstring in Nature. At the same time, the existence of extra dimensions during inflation impacts the tensor to scalar ratio and the running spectral index. We summarize how the constraints on inflation shift when embedded in higher dimensions. Finally, higher dimensions also impact the cosmic expansion through the projection of curvature from the higher dimension in the “dark radiation” term. We summarize current constraints from BBN and the CMB on this brane-world dark radiation term.
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    Antimatter cosmic rays: recent results with the semi-analytic approach
    (2017-05) Salati, Pierre
    The nature of dark matter, an essential component of the Universe, is still unresolved. The best candidate is a weakly interacting particle yet to be discovered at accelerators. In most models, these exotic species annihilate and yield in particular antiprotons and positrons, hence the connection between the dark matter problem and antimatter cosmic rays. Distortions and anomalies in the antiproton and positron spectra are actively searched. A positron excess has actually been discovered and recently confirmed. But claiming that dark matter species have been discovered in the cosmic radiation requires to understand it and to properly model the various backgrounds in which the signal might be found. To achieve this goal, a key ingredient is the transport of charged particles within the magnetic halo of the Milky Way. In this talk, I will focus on a few (semi)-analytic methods used to solve the transport of cosmic rays and derive their fluxes at the Earth. I will then describe the so-called pinching method, which allows for a fast and reliable calculation of the positron spectrum even at low energies. Finally, with the help of this new tool, I will reinvestigate if dark matter can source the positron excess and I will set limits on MeV dark matter candidates
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    Large field inflation: Recent progress and observational predictions
    (2017-05) Linde, Andrei
    I will describe the new generation of inflationary models with plateau potentials and their observational predictions. I will also discuss the problem of initial conditions for inflation in such models.
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    the limits of cosmology
    (2017-05) Silk, Joseph
    One of our greatest challenges in cosmology is understanding the origin of the structure of the universe, and in particular the formation of the galaxies. I will describe how the fossil radiation from the beginning of the universe, the cosmic microwave background, has provided a window for probing the initial conditions from which structure evolved and seeded the formation of the galaxies. I will review the outstanding cosmological issues that remain to be resolved, and suggest an optimal choice of future strategy in order to make further progress on understanding our cosmic origins.
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    A Bitter Pill? The Primordial Lithium Problem
    (2017-05) Fields, Brian
    Big-bang nucleosynthesis (BBN) describes the production of the lightest elements during the first three minutes of cosmic time, and represents our earliest reliable probe of the universe. BBN has stood as both cornerstone of modern cosmology and particle astrophysics, and Keith Olive has made fundamental contributions to BBN over a span of four decades. I will review BBN and Keith's hand in it, emphasizing the transformative influence of cosmic microwave background experiments in precisely determining the cosmic baryon density. Standard BBN combines this with the Standard Model of particle physics to make tight predictions for the primordial light element abundances. Deuterium observations match these predictions spectacularly, helium observations are in good agreement, but lithium observations (in metal-poor halo stars) are significantly discrepant-–this is the ”lithium problem.” Over the past decade, the lithium discrepancy has become more severe, and very recently the solution space has shrunk dramatically, with all resolutions of the problem facing stringent constraints. Future observations will either confirm surprises in stellar astrophysics, or most intriguingly, could reveal new physics at play in the early universe.