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Exotic Physics in the Dark Ages

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					                       Summary

   Future high-redshift 21cm observations will be uniquely
    suitable for constraining exotic physics in the Dark Ages




19 February 2010        Cosmological Reionization   Katie Mack   2/35
                        Summary

   Future high-redshift 21cm observations will be uniquely
    suitable for constraining exotic physics in the Dark Ages

   My work: the evaporation of primordial black holes can
    produce interesting signatures in the all-sky 21cm
    brightness temperature and the power spectrum
    [arXiv:0805.1531]




19 February 2010        Cosmological Reionization   Katie Mack   3/35
                        Summary

   Future high-redshift 21cm observations will be uniquely
    suitable for constraining exotic physics in the Dark Ages

   My work: the evaporation of primordial black holes can
    produce interesting signatures in the all-sky 21cm
    brightness temperature and the power spectrum
    [arXiv:0805.1531]


   Other approaches and focused searches in 21cm can
    improve our understanding of cosmology and
    fundamental physics


19 February 2010        Cosmological Reionization   Katie Mack   4/35
19 February 2010   Cosmological Reionization   Katie Mack   5/35
19 February 2010   Cosmological Reionization   Katie Mack   6/35
      Spin temperature and signal
                                    Spin temp




                                                  Pritchard & Loeb 2008
What happens to this picture
 when energy is injected
  during the Dark Ages?




19 February 2010   Cosmological Reionization    Katie Mack                7/35
    Exotic physics in the Dark Ages
   Astrophysically, the Dark Ages
    are simple: gas is cooling
    adiabatically and undergoing
    gravitational collapse

                                                      Dark Ages




19 February 2010    Cosmological Reionization   Katie Mack   8/35
    Exotic physics in the Dark Ages
   Astrophysically, the Dark
    Ages are simple: gas is
    cooling adiabatically and
    undergoing gravitational
    collapse
                                                       Dark Ages
   If any process injects energy
    into the IGM before z~30, it
    interrupts the cooling and
    alters the 21cm brightness
    temperature

19 February 2010     Cosmological Reionization   Katie Mack   9/35
               Primordial black holes

     

     




19 February 2010     Cosmological Reionization   Katie Mack   10/35
               Primordial black holes

     

     


     



     




19 February 2010     Cosmological Reionization   Katie Mack   11/35
                   Hawking radiation
 Spectrum is roughly
   (but not exactly)
   blackbody spectral
   distribution

• Temperature ~ M-1
• Power ~ M-2
• Lifetime ~ M3




19 February 2010        Cosmological Reionization   Katie Mack   12/35
                   Hawking radiation
 Spectrum is roughly




                                     Power
   (but not exactly)
   blackbody spectral
   distribution

• Temperature ~ M-1
• Power ~ M-2
• Lifetime ~ M3                      Mass



                                             300                     0
                                                    z

19 February 2010        Cosmological Reionization   Katie Mack   13/35
PBH evaporation and IGM ionization
   Currently strongest constraints on PBH
    evaporation come from the gamma-ray
    background
   Alteration of ionization/temperature
    history during Dark Ages may be seen in
    the 21cm signal




19 February 2010   Cosmological Reionization   Katie Mack   14/35
PBH evaporation and IGM ionization
   Currently strongest constraints on PBH
    evaporation come from the gamma-ray
    background
   Alteration of ionization/temperature
    history during Dark Ages may be seen in
    the 21cm signal




19 February 2010   Cosmological Reionization   Katie Mack   15/35
        Results – ionization history




                                               high-mass PBHs




19 February 2010   Cosmological Reionization            Katie Mack   16/35
        Results – ionization history




                                               low-mass PBHs




19 February 2010   Cosmological Reionization           Katie Mack   17/35
   Results – brightness temperature




19 February 2010   Cosmological Reionization   Katie Mack   18/35
Results – 21cm power spectrum



                                M = 5 x 1010 kg




19 February 2010   Cosmological Reionization      Katie Mack   19/35
        10-2


        10-4
                     gamma-ray constraint


        10-6


        10-8


       10-10
                      potential 21cm
                        constraint
       10-12 10
           10      1011       1012               1013      1014
                          PBH mass (kg)
19 February 2010     Cosmological Reionization          Katie Mack   20/35
                   Implications

   21cm observations can detect energy
    injection from PBHs in the Dark Ages
   Limits from 21cm can improve upon
    existing limits




19 February 2010    Cosmological Reionization   Katie Mack   21/35
                   Implications

   21cm observations can detect energy
    injection from PBHs in the Dark Ages
   Limits from 21cm can improve upon
    existing limits

   What about other kinds of exotic physics?



19 February 2010    Cosmological Reionization   Katie Mack   22/35
               Cosmology with 21cm
A few proposed uses of 21cm observations:




19 February 2010    Cosmological Reionization   Katie Mack   23/35
               Cosmology with 21cm
A few proposed uses of 21cm observations:



     Exotic energy injection:




19 February 2010        Cosmological Reionization   Katie Mack   24/35
                Cosmology with 21cm
A few proposed uses of 21cm observations:
      Dark matter decay and annihilation                           (Furlanetto et al. 2006, Valdes
       et al. 2007, Finkbeiner et al. 2008, Myers & Nusser 2008, Natarajan & Schwarz 2009)




19 February 2010                     Cosmological Reionization                 Katie Mack       25/35
               Cosmology with 21cm
A few proposed uses of 21cm observations:



                                                                   • Longer reach
  21cm                                                             than galaxy
  structure                                                        surveys
  mapping:                                                         • More
                                                                   information
                                                                   than CMB



                                                Mao et al. 2008


19 February 2010    Cosmological Reionization                     Katie Mack   26/35
                 Cosmology with 21cm
A few proposed uses of 21cm observations:
      Dark matter decay and annihilation                                  (Furlanetto et al. 2006, Valdes et al.
       2007, Finkbeiner et al. 2008, Myers & Nusser 2008, Natarajan & Schwarz 2009)

      Cosmological parameter estimation                                     (McQuinn et al. 2006, Bowman et al.
       2007, Mao et al. 2008)

      Primordial non-gaussianity (Cooray et al. 2008)
      Varying fundamental “constants” (Katri & Wandelt 2007 & 2009)
      Primordial gravitational waves (Bharadwaj & Sarkar 2009)
      Inflationary parameters (Barger et al. 2009)
      Neutrino masses (Pritchard & Pierpaoli 2008)
      Cosmic superstrings (Khatri & Wandelt 2008)
      Primordial isocurvature perturbations (Gordon & Pritchard 2009)

19 February 2010                          Cosmological Reionization                      Katie Mack          27/35
                     Observations
   21cm brightness temperature
        Exotic physics affects the 21cm all-sky brightness
         temperature signal
   21cm power spectrum
        21cm power spectrum depends on matter power
         spectrum as well as gas physics – can be used to
         distinguish structure formation models
   Redshift space distortions
        If the 3D 21cm power spectrum can be measured
         accurately enough, the underlying matter power
         spectrum can be extracted, which can be tested
         against cosmological models

19 February 2010          Cosmological Reionization   Katie Mack   28/35
  decaying dark matter                   21cm power spectrum
                                                                                      cosmological parameters
                                                                                            α, h, ns, Ωb




                                           Furlanetto et al. 2006
                “exciting” dark matter




                                                                                          Bowman et al.
                                                                                             2007
                                         Finkbeiner et al. 2008

19 February 2010                                          Cosmological Reionization       Katie Mack    29/35
                                           Brightness temperature
decaying dark matter




                                                                                                    decaying and
                                                                                                   annihilating DM
                                        Furlanetto et al. 2006
                                                                                                  Valdes et al 2007
              “exciting” dark matter




                                       Finkbeiner et al. 2008


                          19 February 2010                      Cosmological Reionization   Katie Mack    30/35
        Redshift space information
                                                                    isotropic




                                                                       μ2




                                                              μ4: sourced
                                                               by velocity
                                                              correlations




                                               Pritchard & Loeb 2008


19 February 2010   Cosmological Reionization           Katie Mack        31/35
        Angular power spectrum and
               higher orders                                           primordial isocurvature
                                                                           perturbations

                   annihilating DM




                                                                   Gordon & Pritchard 2009

                                                                 primordial non-gaussianity



     Natarajan & Schwarz 2009


                                         Cooray et al. 2008


19 February 2010                     Cosmological Reionization           Katie Mack     32/35
         Probing really small scales
                                                         distant future
                                                          instrument




                                                         Small scale
                                                         measurements
                                                         plus large
                                                         volume equals
                                                         lots of Fourier
                                                         modes


              Tegmark & Zaldarriaga 2009
19 February 2010             Cosmological Reionization        Katie Mack   33/35
         Probing really small scales
                                                           cosmic superstrings

    varying fundamental “constants”
               Planck




        Khatri & Wandelt 2009



                                                           Khatri & Wandelt 2008
19 February 2010               Cosmological Reionization            Katie Mack   34/35
                     Outlook
   Future 21cm
    experiments can                    Cosmological
                                       parameter
                                                               Improvement in
                                                               constraint with
    constrain cosmology                                        second-
    and exotic physics                                         generation array

   Foregrounds and                    Dark energy density               1.7

    instrumental
    challenges make it                 Matter density                    2.5

    difficult, but worth               Baryon density                    1.5
    trying
                                       Neutrino mass                     3.0


                                       Spectral index ns                 1.4

                                       Running in spectral
    Barger et al.                      index α
                                                                         2.7
       2009
                                                   Furlanetto et al. 2009;
                                                    McQuinn et al. 2006
19 February 2010    Cosmological Reionization             Katie Mack           35/35
19 February 2010   Cosmological Reionization   Katie Mack   36/35

				
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posted:9/5/2012
language:English
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