WHAT POWERED THE BIG BANG?

1. WHAT POWERED THE BIG BANG? WHAT HAPPENSAT THE EDGEOF A BLACK HOLE? Bin Wang 王斌 Department of Physics Fudan University WHAT ISDARK ENERGY? National Aeronautics andSpace Administration

2. 2005--Einstein Year

3. Interesting: . . . accretion disks, Big Bang, black holes, cosmic magnetic fields, cosmic rays, dark energy, dark matter, extreme environments, gamma-ray bursts, jets, large-scale structure, microwave background, neutron stars, nucleosynthesis, relativity, supernovae, . . . 10-25 cm (UHE Cosmic Rays) to 1015 cm (Gravitational waves) Great Decade: CMB fluctuations (COBE, BOOMERanG, MAXIMA, MAP, . . .) Gamma-Ray Bursts (CGRO, HETE-2, Swift, Glast, . . .) Ubiquity of black holes (Chandra, ASCA, HST, . . .) Top priority: Answer the most profound questions raised, but not answered, by Einstein.

4. Einstein’s Predictions Three startling predictions of Einstein’s relativity: • The expansion of the Universe (from a big bang) • Black holes • Dark energy acting against the pull of gravity Observations confirm these predictions . . . . . . the last only four years ago Hubble discovered the expanding Universe in 1929 Black holes found in our Galaxy and at the center of quasars over the past three decades Evidence for an accelerating Universe was observed in 1998

5. Completing Einstein’s Legacy Einstein’s legacy is incomplete, his theory fails to explain the underlying physics of the very phenomena his work predicted • BIG BANG • What powered the Big Bang? • BLACK HOLES • What happens at the edge of a Black Hole? • DARK ENERGY • What is the mysterious Dark Energy pulling the Universe apart? Beyond Einstein will employ a series of missions linked by powerful new technologies and common science goals to answer these questions … … and launch the revolution of the 21st century!

6. What Powered the Big Bang? What Powered the Big Bang? Gravitational Waves Can Escape from Earliest Moments of the Big Bang Inflation (Big Bang plus 10-34 Seconds) Big Bang plus 300,000 Years light Now gravitational waves Big Bang plus 15 Billion Years

7. What Powered the Big Bang? Gravitational waves leave a distinctive imprint on polarization pattern of CMB Gravitational waves from inflation and phase transitions may be detected directly Vacuum energy powered inflation-some form of it may be the “dark energy”

8. What we are currently trying to achieve in cosmology? • To obtain a physical description of the universe, including its global dynamics and matter content; • To measure the cosmological parameters describing the universe, and to develop a fundamental understanding of as many of those parameters as possible; • To understand the origin and evolution of cosmic structures; • To understand the physical processes which took place during the extreme heat and density of the early universe.

9. Observational Results from WMAP Detection of large angle (50 l 150) TE anti-correlation Primordial Perturbations 两个重要结果： 1, 跑动谱指数(running) nS=0.930.03 d nS/dlnk=

10. 2, 小l压低

11. What we hope to learn from CMB? • An initial goal will be to test whether the simplest models of inflation continue to fit the data, meaning models with a single scalar field rolling slowly in a potential V which is then to be constrained by observations. • If this class of models does remain viable, we can move on to reconstruction of the inflaton potential from the data.

12. What we hope to learn from CMB?Brane world • Are there modifications to the evolution of the homogeneous Universe? Yes, RSII model • Are inflationary perturbations different? Yes • Do perturbations evolve differently after they are laid down on large scales? Not clear yet

13. What Happens at the Edge of a Black Hole? Black holes are ubiquitous in the Universe Chandra Deep Image Close to a black hole event horizon, extreme distortions of space & time predicted by Einstein can be observed

14. What Is a Black Hole?

15. Black Holes’ Hairs

16. Spaghettification

17. A Black Hole Candidate

19. Black Hole Imager 0.1 micro arc sec resolution 4-8 m arc sec Image a Black Hole! Hubble, Chandra, and other observatories are showing black holes are common place in the Universe Black holes provide a unique laboratory to test Einstein’s theory of gravity HST Image M87 0.1 arc sec resolution A future black hole imager with a resolution one million times Hubble will observe the effects Einstein predicted X-ray emission from close to the event horizon provides a powerful probe

20. What Happens at the Edge of a Black Hole? X-Ray Spectroscopy • Japan-US ASCA satellite discovered iron lines near the event horizon of a black hole • Line exhibits a strong redshift and provides a unique probe of the inner regions of black holes Gravitational Radiation • Black hole binaries produce gravitational waves in all phases of their evolution • Test of GR in all three phases

21. Do black holes have a characteristic “sound”? • Yes. During a certain time interval the evolution of initial perturbation is dominated by damped single-frequency oscillation. Relate to black hole parameters, not on initial perturbation.

22. What is the Dark Energy? Einstein introduced the Cosmological Constant to explain what was then thought to be a static Universe, “my biggest mistake . . . ” A surprising recent discovery has been the discovery that the expansion of the Universe is accelerating. Implies the existence of dark energy that makes up 70% of the Universe Dark Energy maybe related to Einstein’s Cosmological Constant; its nature is a mystery. Solving this mystery may revolutionize physics . . .

23. What is the Dark Energy? 1.宇宙常数w= -1 2.常数w> -1{宇宙弦（w=-1/3) 畴壁 （w=-2/3) 特殊k-essence 3.动力学模型{Qintessence O(N) Qintessence Chaplygin gas K-essence Braneworld Wet Dark Fluid Chameleon 4. phantom

24. Dark Energy-----CMB Low l Suppress We will use coordinates for the metric of our universe The tendency of preferring closed universe appeared in a suite of CMB experiments The improved precision from WMAP provides further confidence showing that a closed universe with positively curved space is marginally preferred A. Linde(JCAP03);Luminet(Nature03);Efstathiou(MNRAS03) The spatial geometry of the universe was probed by supernova measurement of the cubic correction to the luminosity distance Caldwell astro-ph/0403003; B.Wang & Gong (PLB in press)

25. The Harmonic Function The harmonic function satisfies the generic Helmholtz equation For the flat space, the above Eq. can be solved by Thus the purely spatial dependence of each mode of oscillation in spherical coordinates is represented in the form For the nonzero curvature space, the only change in the metric is in the radial dependence, thus in the curved space

26. The Harmonic Function With our metric, the radial harmonic equation in the curved space is given by is single valued, satisfying the periodic For the requirement that boundary condition CMB power spectrum.

27. HOLOGRAPHIC UNDERSTANDING OF LOW-l CMB FEATURE The relation between the short distance cut-off and the infrared cut-off Translating the IR cutoff L into a cutoff at physical wavelengths we have the smallest wave number at present The comoving distance to the last scattering follows from the definition of comoving time f (z) relates to the equation of state of dark energy w(z)

28. CMB/Dark Energy cosmic duality Thus the relative position of the cutoff is the CMB spectrum depends on the equation of state of dark energy. Given the experimental limits,

29. CMB/Dark Energy cosmic duality CONSTRAINTS ON THE DARK ENERGY FROM THE LOW-l CMB DATA • Static DE • Dynamic DE

30. CMB/Dark Energy cosmic duality • Dynamic DE

31. What is the Dark Energy? We do not know what 95% of the universe is made of!

32. X-Ray Sources: Hydra A Galaxy Cluster

34. Beyond Einstein Program MAP LIGO Hubble Science and Technology Precursors Chandra GLAST

35. Gravitational Wave Astronomy Black holes, neutron stars, and white dwarfs orbiting each other emit gravitational waves Gravitational radiation from black hole mergers can be used to test General Relativity The real voyage of discovery consists not in seeing new landscapes, but in having new eyes. - Marcel Proust

36. Laser Interferometer Space Antenna (LISA) Joint ESA-NASA project • LISA uses a laser based Michelson interferometer to monitor the separation between proof masses in separate spacecraft • Three spacecraft separated by 5 million km • Each spacecraft includes two freely falling test masses with drag free operation • Distance changes measured with precision of 4 ppm RMS over 100 seconds Flight demonstration of disturbance reduction system ST-7 on ESA SMART-2 mission in 2006 micro-newton thrusters LISA, the first space-based gravitational wave antenna, was given strong endorsement by US National Academy of Sciences McKee-Taylor and Turner Committee Reports

37. Constellation-X Use X-ray spectroscopy to observe • Black holes: • Probe close to the event horizon • Evolution with redshift • Dark side of the Universe: • Clusters of galaxies and large-scale structure • Production and recycling of the elements: • Supernovae and interstellar medium • 25-100 times sensitivity gain for high resolution spectroscopy in the 0.25 to 10 keV band • Four satellites at L2 operating as one with advanced X-ray spectrometers Enable high resolution spectroscopy of faint X-ray sources Constellation-X given strong endorsement by US National Academy of Sciences McKee-Taylor and Turner Committee Reports

38. Other Endorsements Royal Swedish Academy of Sciences 2002 Nobel Prize in Physics Riccardo Giacconi “for pioneering contributions to astrophysics, which have led to the discovery of cosmic X-ray sources” Hulse & Taylor (1993); Fowler & Chandrasekhar (1983); Penzias & Wilson (1978); Hewish (1974); Hess (1936); Einstein (1921)

39. Einstein Probes Three focused missions, each designed to address a single high priority science question • Priority and science topic • Dark Energy Probe • Inflation Probe • Black Hole Finder Probe • Competed Principal Investigator missions • Implementation approach determined by peer review • Launched every 3-4 years • $350-500M class missions

40. Astronomy & Astrophysics in the New Millennium • Major Initiatives: • NGST • Constellation-X Observatory • Terrestrial Planet Finder • Single Aperture Far Infrared Observatory • Moderate Initiatives • Gamma-ray Large Area Space Telescope • Laser Interferometer Space Antenna • Solar Dynamics Observatory • Energetic X-Ray Imaging Survey Telescope • Advanced Radio Interferometry Between Space & Earth

41. Connecting Quarks with the Cosmos 2002 (Turner) Not a priority list. • Measure the polarization of the CMB • Determine the properties of dark energy • Use space to probe basic laws of physics (Con-X, LISA) • (Highest energy cosmic rays) • (High-energy-density physics) • (Interagency Initiative) • (Neutrino masses)

42. Beyond Einstein Timeline

43. Education and Public Outreach Big Bang and black holes capture the imaginationand can be usedto teach physical scienceat all levels Beyond Einstein will address the international education priority by inspiring future generations of scientists and engineers, as only WE can . . .

44. The 21st Century How did the Universe begin? Does time have beginning & an end? Does space have edges? The questions are as old as human curiosity. But the answers have always seemed beyond the reach of science. . . until now!