• Mar 25 2013

    WITS Node Seminar: Dr David Marsh (Perimeter Institute)


    The National Institute for Theoretical Physics, and the Centre for Theoretical Physics, School of Physics, would like to invite to its coming talk in the theory seminar series, entitled:

    "Axiverse cosmology and the energy scale of inflation"

    to be presented by Dr. David Marsh (Perimeter Institute)

    Abstract: Ultra-light axions (m_a<10^{ -18} eV), motivated by the so -called "String Axiverse", can be a powerful probe of the energy scale of inflation. In contrast to heavier axions the isocurvature modes in the ultra-light axions can coexist with observable gravitational waves. Here it is shown that large scale structure constraints severely limit the parameter space for axion mass, density fraction and isocurvature amplitude. It is also shown that radically different CMB observables for the ultra-light axion isocurvature mode additionally reduce this space. The results of a new, accurate and efficient method to calculate this isocurvature power spectrum are presented, and can be used to constrain ultra-light axions and inflation.

    Date: Monday, 25th March 2013
    Venue: Frank Nabarro Lecture Theatre P216
    Time: 13.20 - 14.10

    For more information please contact:

    Alan S. Cornell

    School of Physics
    University of the Witwatersrand
    Private Bag 3
    Wits 2050
    South Africa

    Tel.:+27-11-717-6819

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