Path to CDM It Took a Village Rashomon

Path to CDM: It Took a Village Rashomon told by Michael Turner (samurai? ) DM 2018 Kingston, ON 16 July 2018

Some lessons learned • It takes a village!! • Never underestimate the power of a wrong experiment (or paper) to inspire and ultimately do good, transformational science • • Fermilab hi-y anomaly (heavy neutrino) Lee/Weinberg Lubimov et al (electron neutrino mass) HDM Alpha/Bethe/Gamma hot big bang Guth 1981 current inflationary paradigm • The fog of confusion at the frontiers of discovery • Few get it right the first time, but the first step is the most important – start the conversation • Biggest mistake: not taking your ideas seriously enough! (e. g. , and CMB; Lee/Weinberg, Ellis et al on particle relics as DM)

Beginnings (pre 1980 ish) • Dark matter in galaxies and clusters: Oort, Lundmark, Zwicky, van de Hulst, Rubin/Ford, Freeman, Ostriker/Peebles, Faber/Gallagher 1979 • Scale-invariant spectrum: Harrison 1970 • Relic neutrinos: Zel’dovich/Gershtein 1966; Cowsik/Mc. Clelland 1972 & Marx/Szalay 1976. • Freeze out (heavy neutrino): Hut & Lee/Weinberg 1977. Gunn/Lee/Lerche/Schramm/Steigman 1978. NB: with a sentence or footnote (at best) about dark matter • BHs as CDM: White/Rees 1978. • m = 14 to 46 e. V (90% cl): Lubimov et al 1978 • Redshift surveys: Cf. A 1 1982 (Davis/Huchra/Latham/Tonry). Cf. A 2 1989 (Geller/Huchra) • D/H B < 0. 1 so M > 0. 1 particle DM!!: Reeves/Audouze/Fowler/Schramm 1973 to Yang et al 1984 • Inflation (Nuffield Workshop 1982) – took a village too! • Phase-transition: Guth 1981 • Slow roll: Linde & Albrecht/Steinhardt 1982 • / : 1982/3 (Bardeen/Steinhardt/Turner; Guth/Pi; Hawking; Starobinskii)

APS Historical Site May 17, 2013, APS President Michael Turner presented a plaque to the Department of Terrestrial Magnetism (DTM) of the Carnegie Institution for Science: “In recognition of the pioneering research of Vera C. Rubin and W. Kent Ford, Jr. of the Carnegie Institution’s Department of Terrestrial Magnetism, whose measurement of galactic rotation curves provided evidence for the existence of dark matter. ”

Cambridge June 1982 (Nuffield Workshop)

“Cooling: ” HDM WDM (1980 – 1984) • Neutrino-dominated Universe: Steigman/Schramm 1980 (First prize, Gravity Research Foundation Essay) • Cosmological impact of neutrino mass: Szalay et al 1980. (Texas Symposium) • Gravitino DM: Pagels/Primack 1982. • actually, WDM: Bond/Szalay/Turner 1982. • HDM N-body simulations: White/Frenk/Davis 1983 • HDM is dead: Inner. Space/Outer. Space 1984 and elsewhere

1980 s: Go Go junk bond days of early Universe cosmology Gary = church lady? Explore fearlessly the consequences of bold ideas in particle physics about unification to early Universe cosmology Inner Space/Outer Space, May 1984

Birth of Cold Dark Matter (1983 to 85) • Axions as DM 1983 (Abbott/Sikivie; Dine/Fishler/Presskill/Wilczek/Wise) • Axions as CDM 1983 (Turner/Wilczek/Zee) • Neutralino DM 1983/4 (Ellis et al; Goldberg) (only a short sentence about DM) • WDM CDM 1982/84 (Peebles). Modern PS + White/Rees SF • ITP 1984 IS/OS 1984 (Bardeen, White, Davis, Occhionero…). Details of CDM worked out, another village effort • Astrophysical CDM 1984 (Blumenthal/Faber/Primack/Rees) • CDM N-body simulations 1985. Davis/Efstathiou/Frenk/White • Statistics of Peaks/biasing 1986. (Bardeen/Bond/Kaiser/Szalay)

“The troubles” & the path to CDM (1985 – 1998) • • • Too-little power on large scales 1984: evidence for Mh ~ 0. 3? -problem 1984: Turner/Steigman/Krauss 1984; Peebles 1984 Biasing 1984 (solve -problem? ). Kaiser Lake Balaton 1987 (IAU 130). Peebles: CDM is dead! Predicts too much evolution – every evidence that Universe was in place at z = 10. COBE 1992. COBE normalization too much power on small scales now!! Flavors of CDM 1995 (Dodelson/Gates/Turner): CDM, LHCDM, t. CDM, HCDM, o. CDM used to salvage CDM and solve too much power problem Cluster inventory M 0. 3 White et al 1995. CDM 1995 (Krauss/Turner; Ostriker/Steinhardt). Best fit Universe! Flavors of CDM shoot out 1996. Princeton Critical Dialogues in Cosmology w. CDM 1997 (Turner/White). Dark energy with EOS w Great Debate 3 (Peebles/Turner): Is cosmology solved? (October 1998) • originally Peebles/Schramm on = 1? , question had to be re-stated!

Critical Dialogues in Cosmology (June 1996)

Carl Sagan: extraordinary claims require extraordinary evidence! In 1998, the accelerating Universe did not meet the Sagan criterion – but it was the piece of the puzzle that was missing and so was rapidly accecpted.

Great Debate 3: Originally, Peebles/Schramm on Omega (April 1998)

Some other pieces & more troubles(? ) • Direct detection: 1985 to present (10 -40 cm 2 to 10 -47 cm 2 and going down), no WIMP signal (yet) or at CERN LHC • Accelerating Universe 1998: Riess et al; Perlmutter et al • Flat Universe: Boomerang 2000, with earlier strong hints! • H 0 = 71 2 6 km/s/Mpc (Freedman, Kennicutt, Mould et al, 2001) • 2005 – on: SDSS and 2 d. F Large-scale Structure. • CMB Power Spectrum 2001 – on (Boomerang, DASI, WMAP, Planck, ACT, SPT…) • NFW profile: Navarro/Frenk/White 1996 -- strong theories make strong predictions and are easy to falsify! e. g. , steady state • Cusp/core problem • Too many satellites • Too big to fail

Diversions/misdirections (? ) • Cosmic Strings: Kibble, Vilenkin, Turok, Shellard, Albrecht, … 1981 to 2000 (RIP CMB) • Magnetic monopoles: Cabrera 1982 • MOND: Milgrom 1983 • 17 -ke. V neutrino: Simpson 1989 • MACHOs: Alcock et al 1989 to 1998 (RIP) • WDM (again): Dodelson/Widrow 1994 • Annual modulation: DAMA/Libra 1995 – present(!) • WIMPZILLA: Kolb/Chung/Riotto 1998

Challenges: theory and experiment H. L. Mencken (on WIMPs or CDM or both): for every complex problem there is a simple, clear, elegant, and wrong solution “Moore’s Law” in dark matter detection Xenon 1 T 2018 Will astrophysics/cosmology tell us anything about the DM particle beyond hot vs. cold?

The Complicated Universe • Atoms : Democritus to 1964 • + photons: 1964 • + neutrinos (e, μ): 1967 • + exotic dark matter: 1981 • + CDM: 1983/4 • + massive neutrinos: 1998 • + dark energy: 1998 • + τ neutrino: 2000 • Done? Not likely! • Why is ΩCDM/ΩB ≈ 5? I. I. Rabi Who ordered that? How much room: • UR: ~0. 2 CMB • NR: ~0. 1 crit • Other leftovers: ? ?