2019/09/03 by Daniel Friedan, Friedan, Daniel
Physics and Astronomy · #Advanced Differential Geometry Research #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Differential Geometry (math.DG) #FOS: Mathematics #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)
paper · pdf · doi:10.48550/arxiv.1909.01374
openalex publication_date 2019/09/03 · openalex created_date 2019/09/12 · openalex updated_date 2026/07/28
The two-dimensional renormalization group acting as the Ricci flow Λ(∂)/(∂Λ) gμν = Rμν produces a specific 1+3 dimensional space-time metric which describes an expanding universe that starts with a big bang a ∼ t\scriptscriptstyle 1/√3 then decelerates until z=0.2 then accelerates until ending at tmax=1.6 tH with a big blowup a ∼ (tmax-t)\scriptscriptstyle -1/√3. The only free parameters are the overall time scale and the value of the present time t0. These are fixed by the Hubble constant H0=tH-1 and the present deceleration parameter q(t0). This crude calculation of cosmology omits all but the gravitational field. The only energy-momentum is purely gravitational dark matter and energy. This is a preliminary exploration towards a specific, comprehensive, testable calculation of cosmology from a fundamental theory in which physics is produced by a quantum version of the two-dimensional renormalization group.