Attempts to explain CMB Largescale Anomalies KinWang Ng

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

7 o resolution

WMAP 3 CMB sky map

WMAP 1 WMAP 3 Low quadrupole

South-North Power Asymmetry Eriksen et al 04 Park 04 Eriksen et al 04 northern hemisphere southern hemisphere full sky North pole (80 o, 57 o)

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 1 o now At last scattering surface, 400, 000 yrs after big-bang l 7 o angular scale l Each 7 o pixel contains many q l = 180 degrees/ q COBE DMR MAP 1 o regions l Measuring super-horizon temperature fluctuations l So smooth (1 in 105)!! Why? ? l Primordial density fluctuations that seed large scale structures

Inflation and Primordial Density Fluctuations

r : tenor/scalar WMAP 3 and chaotic inflation m ～ 1013 Ge. V

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) l. General slow-roll condition (Steward) |n-1|~|dn/dlnk| l. Multi-field (Vernizzi, Tent, l Rigopoulos, Yokoyama et al) letc 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 l. Driven by a colored noise from interacting quantum environment (Wu et al) l l. 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 non. Gaussianity, 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

Inf lat ion 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 Λ 1 Λ 2 Will these bubbles collapse into black holes? Tye, Shiu, …

Motion of the bubble wall surface tension bubble radius