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Messages from the Big Bang George Chapline and Jim Barbieri CGC Miami 2017. The MACHO mass spectrum provides a look at the physics underlying the big bang!. Introduction.
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Messages from the Big Bang George Chapline and Jim Barbieri CGC Miami 2017 The MACHO mass spectrum provides a look at the physics underlying the big bang!
Introduction It has been argued that in a quantum theory of gravity infinite de Sitter space is unstable at the de Sitter horizon, resulting in an expanding gas of massive compacts objects aka “dark energy stars”. It was suggested some time ago (GC 2005 “Texas” Conference) that in fact dark matter consists entirely of primordial dark energy stars. In this talk I will describe how the physics of dark energy stars allows one to make use of present day MACHO mass spectrum to infer the magitude of the vacuum energy at the time of the big bang,
Negative vacuum enegy theory of the big bang J. Barbieri and GC 2015
Trapped surfaces in a flat universe with a negative cosmological constant
In a quantum theory of gravity gravitational collapse results in a “dark energy star”: J Barbieri and GC IJMP 2014 (a) (b) (c) (d)
In the “Hadean Era”the universe contains onlymassive dark energy stars
Formation of massive compact objects during the Hadean Era • The initial epoch of our expanding universe is a violent era where the primordial MACHOs evolve as a result of collisions and gravitational collapse. • The matter equation of state is very soft during this era because of the enormous specific heat of compact objects, leading to gravitational collapse on every scale [ GC PRD 12, 2949 (1975)] • In an Einstein de Sitter universe with a Harrison-Zeldovich spectrum of density fluctuations all compact objects will be swept up into massive compact objects created at the horizon scale.
Dark energy stars are very different from BHs R Laughlin & GC 2000
At low frequencies the surfaces of compact objects are transparent (as in classical GR) but at a critical frequency the surfaces become opaque
Compact objects and the entropy of the universe GC 2010 Some time ago it was independently realized by one of us (GC) and Paul Frampton that an understanding the entropy of the universe will require that the matter in the early universe consist almost entirely of massive compact objects. The opacity of the surface of dark energy stars for elementary particles with energies above a critical value explains how the entropy generated in the Hadean era gets converted into radiation.
Origin of the Cosmic Microwave Background GC 2010 When the temperature of the compact objects created by coalescence of the primordial compact objects created at the onset of the Hadean era reaches a critical value ~ (Mo/M)1/2Gev, the entropy tied up in the internal excitations of the Hadean compact objects will be released, creating the radiation precursor for the present day CMB. • The observed # CMB photons per gram dark matter suggests that the CMB originated at z ~ 1011.
The compact seeds for present day dark matter have a unique mass • In principle a quantum theory of gravity could be used to calculate the residual masses of the dark energy stars remaining after the massive compact objects formed at the end of the Hadean era by gravitational collapse radiated away most of their mass • A more direct approach is to simply make use of the present day densities of dark matter (~ 1keV/cc) and the CMB (.026eV/cc). The result is
Evolution of the MACHO mass spectrum during the radiation era • During the radiation era the mass spectrum of the dark matter compact objects evolves as a result of collisions; allowing the mass spectrum to be calculated using a Boltzmann-like eq: where bcap is the critical impact parameter that allows the colliding compact objects to coalesce via gravitational radiation (Bae et al 2017)
In order to reproduce the fraction of galactic seeds one must use the gravitational capture rather than geometric cross-secture!
Astrophysical Constraints on MACHO masses • Micolensing • Alcock et al. 2001 • Tisserand et al. 2007 • CMB • Ali-Haïmoud & Kamionkowski 2016 • Wide Binary • Yoo et al. 2004
Summary The entropy of the CMB, present day density of dark matter, and necessity for primordial compact seeds for galaxies all point to a pre-big bang negative vacuum energy ~ - (TeV)4. • Evidently the big bang is associated with supersymmetry breaking The “smoking gun” will be the mass spectrum of the MACHOs which constitute the dark matter in our galaxy
Microlensing by a compact object can be distiguished from stellar variability by the fact that it is achromatic Variable stars have variable colors Microlensing signal is the same for all colors
Gravitational micolensing provides a direct test of the prediction that dark matter consists of compact objects with masses ~ solar mass
Microlensing is seen as a transient brightening of a background star
In principle the parallax signal would allow one to search for microlensing events using a FFT algorithm. Unfortunately this doesn’t work in practice because of the Lomb-Scargle effect This signal requires MACHO masses > 5 solar masses