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Attempts to explain CMB Large-scale Anomalies Kin-Wang Ng (吳建宏) Academia Sinica, Taiwan NTU String Group, June 18, 2010 Thanks: Hsien-Chun Wu, I-Chin Wang, Da-Shin Lee, Wolung Lee, Hing-Tong Cho,Yeo-Yie Charng, Shang-Yung Wang 7o resolution WMAP3 CMB sky map WMAP1 WMAP3 Low quadrupole South-North Power Asymmetry Eriksen et al 04 Park 04 Eriksen et al 04 northern hemisphere southern hemisphere full sky North pole (80o,57o) Land & Magueijo 05 “Axis of Evil” l=2, quadrupole l=3, octopole Foreground problem?? Size of a casually connected region (horizon -- distance travelled by light in 400,000 yrs) is about 1o now At last scattering surface, 400,000 yrs after big-bang 7o angular scale Each 7o pixel contains many q l = 180 degrees/ q COBE DMR MAP 1o regions Measuring super-horizon temperature fluctuations So smooth (1 in 105)!! Why?? Primordial density fluctuations that seed large scale structures Inflation and Primordial Density Fluctuations r : tenor/scalar WMAP3 and chaotic inflation m ～ 1013 GeV Inflation and Primordial Density Fluctuations roughness of H inflation starts here periodic universe, more….. H A Challenge to Standard Slow-roll inflation!? Slow-roll kinematics Slow-roll conditions violated after horizon crossing (Leach et al) General slow-roll condition (Steward) |n-1|~|dn/dlnk| Multi-field (Vernizzi, Tent, Rigopoulos, Yokoyama et al) etc Quantum fluctuations Chaotic inflation – classical fluctuations driven by a white noise (Starobinsky) or by a colored noise (Liguori, Matarrese et al.) coming from high-k inflaton Driven by a colored noise from interacting quantum environment (Wu et al) Others Our Inflaton-Scalar Interacting Model Single-field inflation〈σ〉= 0 (Wu et al 07) Trace out sigma field to obtain : Feynman & Vernon 1963 Influence Functional Method semi-classical Dissipation imaginary part Colored, dependent on history Noise real part Start of inflation Dominant passive fluctuations and low CMB quadrupole assuming no active de Sitter quantum fluctuations Conclusion I • We propose a new dynamical source for density perturbation: Colored Quantum Noise - give a low CMB quadrupole • Can be applied to trapped inflation (Green et al. 09) • Working on running spectral index and nonGaussianity, both are natural with colored noise ns Dissipation? Relative large three-point functions A black hole in inflation Cho, Ng, Wang 09 Schwarzschild-de Sitter M - black hole mass H - Hubble parameter Static ------> Planar Inflaton fluctuations Expansion parameter where the source term Solutions Zero order First order Power spectrum de Sitter quantum fluctuations End of inflation → 0 Possible effects to CMB anisotropy early universe present universe e.g. black holes formed via thermal fluctuations Chen, Gruber, Ng, Scardigli 10 Carroll, Tseng, & Wise 08 preferred point, line, or plane Conclusion II • Hints from WMAP data on beyond standard slow-roll inflation !? • A fine tuning – physics just at 60 e-foldings • Maybe there is a window to see the first few e-foldings of inflation !? • From homogeneous to directional effects • Or we are all fooled by probability – it is indeed a Gaussian quantum process • Nongaussianity is an important check Speculations • Is it possible not to fine tune inflation duration to 60 efolds? • Then there must be something happening during slow-roll inflation • Formation rate must not be far below the expansion rate of inflation String Landscape • 10500 de Sitter vacua • Metastable, bubble nucleation via tunneling • Barriers of string scale, slow tunneling rate • The spacetime is a hierachy of de Sitter vacuum bubbles • Most part in eternal inflation • Some regions tunnel down to flat potential for slow-roll infaltion • We sit in a vacuum with a small cosmological constant today Efficient and rapid tunneling slow-roll inflation in a de Sitter vauum Λ1 Λ2 Will these bubbles collapse into black holes? Tye, Shiu,… Motion of the bubble wall surface tension bubble radius