1 / 42

New Views of the Universe

New Views of the Universe. David Schramm’s Legacy. Rocky Kolb (don’t call me Mike Turner) Particle Astrophysics Center, Fermilab & University Chicago. Dave’s Ph. D. advisors at Caltech. Willy Fowler Kellogg Radiation Laboratory. Jerry Wasserburg The Lunartic Asylum. Some of Willy’s Boys.

gada
Download Presentation

New Views of the Universe

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. New Views of the Universe David Schramm’s Legacy Rocky Kolb (don’t call me Mike Turner) Particle Astrophysics Center, Fermilab & University Chicago

  2. Dave’s Ph. D. advisors at Caltech Willy Fowler Kellogg Radiation Laboratory Jerry Wasserburg The Lunartic Asylum

  3. Some of Willy’s Boys Dave Arnett, Jean Audoze, John Bahcall, Dick Bond, Geoff Burbidge, Margaret Burbidge, Don Clayton, George Fuller, Rocky Kolb, Grant Matthews, Dave Schramm, Gary Steigman, Jim Truran, Bob Wagoner, Craig Wheeler, Stan Woosley, …

  4. Precision cosmology MAP WMAP • Consult entrails of chickens, • prophecies of Nostradamus, • & the Kabbalah Priors • Greater accuracy if combine with other data • CMB • 2dFGRS • SDSS • Ly-a • SN Ia

  5. LCDM • Inflation-produced perturbations • Baryo/leptogenesis

  6. Mission accomplished … … or premature jubilation?

  7. Desperate Physicists V(f) • L • SUSY Inflation • Dark Energy • Dark Matter How Far Will They Go? How Far Will They Go?

  8. Dark-matter

  9. MatterWM ~ 0.3 dynamics lensing x-ray gas cmb power spectrum simulations

  10. BaryonsWB ~ 0.04 Ly-a agrees with WMAP QSO 1937-1009 Burles et al. Tytler

  11. Cold thermal relics actual freeze out Relative abundance equilibrium T/MX X/a-1 Not quite so clean: • s-wave or p-wave? • annihilation or scattering cross section? • co-annihilation? • sub-leading dependence on mass, g*, etc. • targets are nuclei (spin-dependence)

  12. Cold thermal relics WX sA-1

  13. Seeking SUSY * Assumed here to be • Hierarchy problem: • fundamental scale is Planck mass* • observe particles with mass much less than Planck mass • gauge bosons protected by gauge symmetry • fermions protected by chiral symmetry • scalars (e.g., Higgs) defenseless! • introduce supersymmetry to protect scalars • Supersymmetric Standard Model: • 105 parameters • Constrained Minimal Supersymmetric Standard Model: • 3 parameters: • Lightest supersymmetric particle (LSP) stable: • neutralino?

  14. Cold thermal relics (neutralino) • 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

  15. Cold thermal relics Cryogenic Dark Matter Search • SUSY shaded areas • Probing significant regions • of MSSM model space • Light-mass region largely • ruled out • Another factor of 100 • may be needed DAMA NaI/1-4 3s region PRELIMINARY ZEPLIN I EDELWEISS Combined Soudan limits

  16. Muons from the sun

  17. The nature of dark matter is a complex natural phenomenon. The neutralino is a simple, elegant, compelling explanation. “For every complex natural phenomenon there is a simple, elegant, compelling, wrong explanation.” - Tommy Gold

  18. Many variations of error • sterile neutrinos, gravitinos (warm dark matter) • LSP (neutralino, axino, …) (cold dark matter) Interaction strength range Mass range axions axion clusters Noninteracting: wimpzillas Strongly interacting: B balls • neutrinos (hot dark matter) • LKP (lightest Kaluza-Klein particle) • axions, axion clusters • solitons (Q-balls; B-balls; Odd-balls, Screw-balls….) • supermassive wimpzillas

  19. Inflation ? Who is the inflaton

  20. Imprint of inflation Seeds of Structure + Gravitational Waves Inflation Big Bang plus 10-35? seconds Big Bang plus 380,000 Years Big Bang plus 14 Billion Years

  21. Comparison to observation: • a (nearly exact) power-law • spectrum of gaussian • super-Hubble-radius • scalar perturbations (seeds of structure) & • tensor perturbations (gravitational waves) • related by a consistency relation • in their growing mode • in a spatially flat universe.

  22. Harrison-Zel’dovich Spectrum ? n=1?, n’=0?, r=0? • Combine CMB, LSS, Ly-a? • Tensor modes? • Consistency relation?

  23. Issues • Who is the inflaton? • models of inflation, reconstruction? • Transplanckian physics? • probe of short-distance physics? • Defrosting? • preheating, reheating, ….? • Extra dimensions, brane, bulk, etc.? • new dynamics? • Other particle production? • WIMPZILLAS, gravitnos, ….? • Are perturbations from the inflaton fluctuations? • curvaton, modulon, …

  24. The nature of inflation is a complex natural phenomenon. Single-field, slow-roll inflation is a simple, elegant, compelling explanation. “For every complex natural phenomenon there is a simple, elegant, compelling, but wrong explanation.” - Tommy Gold

  25. The gravity of dark energy Main Entry: grav·i·ty Function: nounEtymology: Middle French or Latin; Middle French gravité, from Latin gravitat-, gravitas, from gravis1 a : dignity or sobriety of bearing b : IMPORTANCE,SIGNIFICANCE;especially: SERIOUSNESSc : a serious situation or problem2 : WEIGHT3 a (1) : the gravitational attraction of the mass of the earth, the moon, or a planet for bodies at or near its surface (2) : a fundamental physical force that is responsible for interactions which occur because of

  26. The case for L: 1) Hubble diagram dL(z) • 2) subtraction • WTOTAL = 1 • WM = 0.3 • 1 - 0.3 = 0.7 WVACUUM 3) age of the universe 4) structure formation 5)  Einstein-de Sitter flat, matter-dominated model (maximum theoretical bliss) WMATTER

  27. Cosmo-illogical constant? GUT EWK BBN REC Illogical magnitude (what’s it related to?): Illogical timing (why now?):

  28. 10-33 eV scalar fields!!! • modification of gravity • extra dimensions • branes and bulk • Lorentz violating vector fields • Friedmann equation incomplete (then there are the crazy ideas)

  29. Practical tools for dark energy scalar fields anthropic principle (the landscape)

  30. Entertaining conjecture (creeping murmur) Now entertain conjecture of a timeWhen creeping murmur and the poring darkFills the wide vessel of the universe. — King Henry Vth

  31. Modifying the left-hand side • Braneworld modifies Friedmann equation • Phenomenological approach • Gravitational force law modified at large distance • Tired gravitons • Gravity repulsive at distance R Gpc • n=1 KK graviton mode very light, m  (Gpc)-1 • Einstein & Hilbert got it wrong • Backreaction of inhomogeneities Binetruy, Deffayet, Langlois Freese & Lewis Deffayet, Dvali & Gabadadze Five-dimensional at cosmic distances Gregory, Rubakov & Sibiryakov; Dvali, Gabadadze & Porrati Gravitons metastable - leak into bulk Csaki, Erlich, Hollowood & Terning Kogan, Mouslopoulos, Papazoglou, Ross & Santiago Carroll, Duvvuri, Turner, Trodden Räsänen;Kolb, Matarrese, Notari & Riotto; Notari; Kolb, Matarrese & Riotto

  32. Acceleration from inhomogeneities • Most conservative approach — nothing new • no new fields (like 10-33 eV mass scalars) • no extra long-range forces • no modification of general relativity • no modification of Newtonian gravity at large distances • no Lorentz violation • no extra dimensions, bulks, branes, etc. • no faith-based (anthropic) reasoning • Magnitude?: calculable from observables related to  / • Why now?: acceleration triggered by era of non-linear structure

  33. Acceleration from inhomogeneities Homogeneous model Inhomogeneous model We (Kolb, Matarrese, Riotto + others) think not!

  34. Acceleration from inhomogeneities Cosmology  scalar field theory analogue cosmology scalar-field theory zero-mode ahi (vev of a scalar field) non-zero modes inhomogeneities thermal/finite-density bkgd. modify a(t) modify h(t)i e.g., acceleration e.g., phase transitions physical effect • View scale factor as zero-momentum mode of gravitational field • In homogeneous/isotropic model it is the only degree of freedom • Inhomogeneities: non-zero modes of gravitational field • Non-zero modes interact with and modify zero-momentum mode

  35. Different approaches Standard approach Our approach • Model an inhomogeneous • Universe as a homogeneous • Universe model with r=hi • Zero mode [a(t) /V1/3] is the • zeromode of a homogeneous • model with r= hi • Inhomogeneities only have a • local effect on observables • Cannot account for observed • acceleration • Expansion rate of an • inhomogeneous Universe  • expansion rate of homogeneous • Universe with r=hi • Inhomogeneities modify • zero-mode [effective scale • factor is aD  VD1/3 ] • Effective scale factor has a • (global) effect on observables • Potentially can account for • acceleration without • dark energy or modified GR

  36. Acceleration without dark energy!!!!! DON’T KILL ROCKY

  37. Many issues: This meeting: • non-perturbative nature • shell crossing • comparison to observed LSS • gauge/frame choices • physical meaning of coarse graining • Hirata • Fry • Afshordi Program: • can inhomogeneities change effective zero mode? • how does (does it?) affect observables? • can one design an inhomogeneous universe that accelerates? • could it lead to an apparent dark energy? • can it be reached via evolution from usual initial conditions? • does it at all resemble our universe? • large perturbative terms resum to something harmless?

  38. How Do We Sort It Out? Precision measurements of w, wa, 

  39. Medicean stars + Galileo Galilei Cosimo II Georgium sidus + William Herschel George III

  40. Dark energy parameter, w George “Dubya” Bush w + George II

  41. New Views of the Universe David Schramm’s Legacy Rocky Kolb Particle Astrophysics Center, Fermilab & University of Chicago

More Related