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IDM 2018

22–27 Jul 2018
MacMillian
US/Eastern timezone

Mary Ann Rotondo

Session

4.4 Axions

4.4
26 Jul 2018, 14:00
117 (MacMillian)

117

MacMillian

Brown University Providence, Rhode Island, USA

Conveners

4.4 Axions

  • David Pinner

Presentation materials

There are no materials yet.

  1. 47. The Stochastic Axion Scenario
    adam scherlis (Stanford University)
    26/07/2018, 14:00
    Theory
    Talk

    For the minimal QCD axion model it is generally believed that overproduction of dark matter constrains the axion mass to be above a certain threshold, or at least that the initial misalignment angle must be tuned if the mass is below that threshold. We demonstrate that this is incorrect. During inflation, if the Hubble scale is low, the axion tends toward an equilibrium. This means the minimal...

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  2. 103. Cosmological adiabatic conversion between QCD axion and ALP
    Fuminobu Takahashi (Tohoku University)
    26/07/2018, 14:20
    Theory
    Talk

    We study the adiabatic conversion between the QCD axion and axion-like particle (ALP) at level crossing
    which occurs when their masses become close to each other in the early universe. This is similar to the
    Mikheyev-Smirnov-Wolfenstein effect in neutrino oscillations. I explain a scenario where the ALP produced
    by the adiabatic conversion of the QCD axion explains the observed dark matter...

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  3. 108. Non-relativistic effective field theory of scalar field and longevity of condensates
    Dr Masaki Yamada (Tufts University)
    26/07/2018, 14:40
    Theory
    Talk

    Ultra light bosonic dark matter like axion may form long-lived condensate. The longevity of the condensate can be understood by the approximate number conservation in the non-relativistic regime. The profile of condensate is obtained via the bounce method, just like Q-balls, as long as the number violating interaction is weak enough. I will discuss the decay processes of the condensate by the...

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  4. 118. Dark Matter-Baryon Scattering in Global 21cm Signal
    Chih-Liang Wu (MIT)
    26/07/2018, 15:00
    Indirect Detection
    Talk

    We compare several cosmological constraints on the cross section for elastic scattering between DM and baryons over a wide range of epochs in cosmological history. The result shows that given high-redshift constraints on DM-baryon scattering, long-range interactions for light DM would be sufficient to explain the deep 21cm absorption trough recently claimed by the EDGES experiment. For...

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  5. 99. Early dark energy and the Hubble tension
    Tanvi Karwal (Johns Hopkins University)
    26/07/2018, 15:20
    Theory
    Talk

    Although the $\Lambda$CDM model is in excellent agreement with the observed CMB, its prediction for the current rate of expansion of the universe is in tension with observations of the local universe at $ > 3 \sigma$. Furthermore, theoretically motivating a cosmological constant has proved difficult. In this talk, I will discuss a solution to the Hubble tension in the form of early dark...

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  6. 109. Duration of classicality of the axion dark matter condensate
    Dr Ariel Arza (University of Florida)
    26/07/2018, 15:40
    Theory
    Talk

    Axion dark matter is commonly considered as a classical self-interacting scalar field condensate. This talk takes the axion as a quantum scalar field and shows how long the classical description is valid considering gravitational and contact self-interactions. When the axion field is homogeneus and interacts with itself by attractive forces, parametric resonance causes quanta to jump in pairs...

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