The Very Early Universe 25 Years On Rocky Kolb, University of Chicago

1. WIMPZILLAS Dark Matter From Inflation The Very Early Universe 25 Years On Rocky Kolb, University of Chicago

2. Dark Matter • MOND (Modified Newtonian Dynamics) Takes a Bullet • Planets • Size challenged stars Ruled out by MACHO expts. brownred white • Black holes • Primordial relic particle

3. Cold Thermal Relic* actual equilibrium freeze out Relative abundance T/MX WX  sA-1 (independent of mass) MX 200TeV * An object of particular veneration.

4. Cold Thermal Relic* * An object of particular veneration.

5. Cold Thermal Relic* • Direct detection (sS) • More than a dozen experiments • Indirect detection (sA) • Annihilation in sun, Earth, galaxy. . . neutrinos, positrons, antiprotons, g rays, . . . • Accelerator production (sP) • Tevatron, LHC, ILC * An object of particular veneration.

6. Cold Thermal Relic* Favorite cold thermal relic: the neutralino • Study “constrained” MSSM models • Typical SUSY models consistent w/ collider data have too • small annihilation cross section  too large W • Need chicanery to increase annihilation cross section • s-channel resonance through light H and Z poles • co-annihilation with or • large tanb (s-channel annihilation via broad A resonance) • high values of m0–LSP Higgsino-like & • annihilates into W & Z pairs (focus point) • … • or, unconstrained * An object of particular veneration.

7. Cold Thermal Relic* Favorite cold thermal relic: the neutralino “a simple, elegant, compelling explanation for a complex physical phenomenon” “For every complex natural phenomenon there is a simple, elegant, compelling, wrong explanation.” - Tommy Gold * An object of particular veneration.

8. Particle relic from the bang Interaction strength range Mass range axions axion clusters Noninteracting: wimpzillas Strongly interacting: B balls • neutrinos (hot dark matter) • sterile neutrinos, gravitinos (warm dark matter) • LSP (neutralino, axino, …) (cold dark matter) • LKP (lightest Kaluza-Klein particle) • axions, axion clusters • solitons (Q-balls; B-balls; Odd-balls, ….) • supermassive wimpzillas

9. WIMPZILLAS example of a non-thermal relic SIZE DOES MATTER visit wimpzillas.com

10. Supermassive particles • Production Mechanisms: • Gravitational Chung, Kolb, Riotto; Kuzmin & Tkachev • ReheatingChung, Kolb, Riotto • PreheatingChung • Bubble collisions Chung, Kolb, Riotto • Transplanckian effectsKolb, Starobinski, Tkachev

11. Proper vibrations of the expanding universe .. Erwin Schrodinger Physica6, 899(1939) Introduction: “… proper vibrations [positive and negative frequency modes] cannot be rigorously separated in the expanding universe. … this is a phenomenon of outstanding importance [density perturbations from inflation, WIMPZILLAS]. With particles it would mean production or annihilation of matter, merely by expansion,… Alarmed by these prospects, I have examined the matter in more detail.” Conclusion: “… There will be a mutual adulteration of positive and negative frequency terms in the course of time, giving rise to … the ‘alarming phenomenon’…”

12. Proper vibrations of the expanding universe .. Erwin Schrodinger Physica6, 899(1939) Creation of a single pair of particles per Hubble volume per Hubble time with “Hubble energy” Alarming?

13. Expanding Universe Particle Creation Discovery: Schrödinger (1939) The Proper vibrations of the expanding universe “the alarming phenomenon” 1939—1982: It’s a bug! Arnowit, Birrell, Bunch, Davies, Deser, Ford, Fulling, Grib, Hu, Kofman, Lukash, Mostepanenko, Page, Parker, Starobinski, Unruh, Vilenkin, Wald, Zel’dovich,… First application:density perturbations, gravitational waves from inflation (Guth & Pi; Starobinski; Bardeen, Steinhardt, & Turner; Hawking; Rubakov; Fabbi & Pollack; Allen) 1983—present: It’s a feature! • This application: dark matter • (Chung, Kolb, & Riotto; Kuzmin & Tkachev) • require (super)massive particle “X” • stable (or at least long lived) • initial inflationary era followed byradiation/matter

14. Preliminaries • Scalar mode wave functions in large k ( k  H ) region • WKB approximation ( Mk  H ) • Number density related to Bogoliubov coefficient bk

15. Particle production Field theory: the result is almost alwaysinfinite! finite result if finite fails at inflation fails at matter/ radiation finite if start in inflation, end in matter/radiation

16. Particle creation in nonadiabatic region H / HMf preheating, reheating, …? chaotic inflation conformal coupling nonadiabatic region: particle creation

17. Particle production atend of inflation conformal coupling h= conformal time h = 1 end of inflation

18. Spectrum red flat blue Kuzmin & Tkachev

19. Particle production Chung, Kolb & Riotto; Kuzmin & Tkachev chaotic inflation

20. Model exploration • Gravitational Production: • FermionsKuzmin & Tkachev • Non-conformal couplings Kuzmin & Tkachev • Small-field models Crotty, Chung, Kolb, Riotto • Hybrid models Crotty, Chung, Kolb, Riotto

21. Model exploration Chung, Crotty, Kolb, Riotto natural hybrid WX h2 (TRH /109GeV)-1 WX h2 (TRH /109GeV)-1 He= 61012GeV MX / He MX / He

22. Supermassive particles • Inflaton mass (in principle measurable from gravitational • wave background, guess 1012GeV) may signal a new mass • scale in nature. • Other particles may exist with mass comparable to the • inflaton mass. • Conserved quantum numbers may render the particle stable. • They almost certainly will be produced in inflation.

23. Wimpzilla characteristics • abundance depends only on mass • If DM, supermassive: 109 - 1019GeV (~1012GeV ?) • abundance independent of interactions • only gravitational interactions? • electrically charged? • strong interactions? • weak interactions? • require “large” reheat temperature (limit to • TRH in gravity-mediated SUSY breaking) • prefers “large” H during inflation  “large” • gravitational-wave background.

24. WIMPZILLA footprints: Annihilate: Galactic Center, Sun Direct Detection:Underground Searches Decay: Ultra High Energy Cosmic Rays Isocurvature modes: CMB, Large-scale structure

25. Annihilation in Sun WIMPZILLAS solarns Detect ns in IceCube Sun in solar neutrinos Ice Cube sings about it • WIMPZILLAS accrete and accumulate in center of sun • They annihilate producing high-energy neutrinos • Neutrinos detected on Earth • Required cross section ruled out by direct detection limits Albuquerque, Crotty, Hui, Kolb

26. Direct detection Direct detection not promising for small cross sections or very large masses Albuquerque & Baudis

27. Ultra-High Energy Cosmic Rays • UHECRs observed with • energies in excess of 1020eV! • Possible origin is decay of • WIMPZILLAS • Expect: • correlation with galactic center • “large” photon component • Seems not to be the case • correlation with nearby AGNs (black holes) • likely proton primaries

28. Isocurvature modes • For thermal relics, origin of DM is thermal—naturally small • isocurvature perturbations • For nonthermal relics (like WIMPZILLAS, axions) isothermal • perturbations likely to arise • For WIMPZILLAS, correlations between curvature and • isocurvature perturbations—same origin (quantum fluctuations) • Limits on isocurvature contributions not very strong, but still • limit parameter space Chung, Kolb, Senatore, Riotto

29. Isocurvature modes Too Much DM Overproduce Isocurvature Too Little DM Chung, Kolb, Senatore, Riotto

30. Transplanckian Wimpzillas • In Transplanckia, particles emerge as momentum crosses “new- • physics” hypersurface at R-1 = LMPl. • They emerge with momentum kL – so can produce • WIMPZILLAS if M L. • Can produce WIMPZILLS as dark matter with very low H (say • 108GeV), even if bk2 (H/L)2 • This can relax limits from isocurvature contributions Kolb, Starobinski, Tkachev

31. Conclusions • Origin of inflationary perturbations from creation of particles in • the expanding universe • Beautiful ideas often have other applications • Nature uses only the longest threads to weave her patterns… • –– Feynman • Perhaps origin of dark matter also from creation of particles in • the expanding universe (it’s a long thread!) • Dark matter may have only gravitational interactions • (an inconvenient possibility)

32. Dark Matter WIMP or WIMPZILLA