Kin-Wang Ng

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Inflation after WMAP

Kin-Wang Ng ()

Academia Sinica, Taiwan

2nd International Workshop onDark Matter, Dark Energy, and

Matter-Antimatter Asymmetry

Hsinchu, Nov 5 6 , 2010

Collaborators: Yeo-Yie Charng, Hing-Tong Cho, Da-Shin Lee, Wolung Lee,

I-Chin Wang, Chun-Hsien Wu


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Outline

Cosmic background backgroud anisotropyand WMAP observation

Primordial density perturbationscale-invariant, running spectral index, Gaussianity

Large-scale CMB anomalies

Implications to inflation


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7-yearWMAP 2010


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PR(k)= (/)2


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Runningspectralindex


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Inflation and Primordial Density Fluctuations


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H


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|dn/dlnk|


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Curvature potential

Slow-roll inflation

WMAP3 Data onNon-Gaussianity

2=/

Radiation transfer function


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Large-scale CMB anomalies


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WMAP1 WMAP3

Low quadrupole


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South-North Power Asymmetry

Eriksen et al 04

Eriksen et al 04Park 04

North pole (80o,57o)northern hemispheresouthern hemispherefull sky


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WMAP3CMB sky map


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Axis of EvilLand & Magueijo 05

l=2, quadrupole

l=3, octopole


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A Challenge to Standard Slow-roll inflation!?

Slow-roll kinematics Quantum fluctuations

Slow-roll conditionsviolated after horizoncrossing (Leach et al)

General slow-rollcondition (Steward)

|n-1|~|dn/dlnk|Multi-field (Vernizzi, Tent,Rigopoulos, Yokoyama et al)

etc

Chaotic inflation

classical fluctuations drivenby a white noise (Starobinsky)or by a colored noise(Liguori, Matarrese et al.)

coming from high-k inflatonDriven by a colored noisefrom interacting quantumenvironment (Wu et al)Trapped inflation (Green et al)


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Our Inflaton-Scalar Interacting Model

Single-field inflation= 0

(Wu et al 07)


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Trace out sigma field to obtain :

Colored,dependenton history

Dissipation Noise

imaginary part real part

Feynman & Vernon 1963Influence Functional Method

semi-classical


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Start of inflation


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Dominant passive fluctuations and low CMB quadrupole

assuming no active de Sitter quantum fluctuations


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Running spectral index and Non-gaussianity

We propose a new dynamical source for densityperturbation: Colored Quantum Noise

- give alow 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

Relative largethree-point functions

ns

Dissipation?


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Following is an effort to go

from homogenous todirectional effects


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A black hole in inflation Cho, Ng, Wang 09

Schwarzschild-de SitterM - black hole massH - Hubble parameter

Static ------> Planar


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Inflatonfluctuations

Expansionparameter

where the source term


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Solutions

Zero order

First order


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Power spectrum

de Sitterquantum fluctuations

End of inflation 0


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Possible effects to CMB anisotropy

Carroll, Tseng, & Wise 08 preferred point, line, or plane

present universeearly universe

e.g. black holesformed viathermalfluctuations

Scardigli et al.


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Speculations

Is it possible not to fine tune inflationduration to 60 efolds?

Then there must be something taking

place during slow-roll inflation

Formation rate must not be far below theexpansion rate of inflation

e.g. Collapse of density peaks of quantumfluctuations during inflation or


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String Landscape

10500

de Sitter vacua Metastable, bubble nucleation viatunneling

Barriers of string scale, slowtunneling rate

The spacetime is a hierachy of deSitter vacuum bubbles

Most part in eternal inflation

Some regions tunnel down to flatpotential for slow-roll infaltion We sit in a vacuum with a small

cosmological constant today


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Efficient and rapid tunneling

slow-roll inflation in a de Sitter vauum 2

Will these bubbles 1collapse

into black holes?

Tye, Shiu,

12

M ti f th b bbl ll


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Motion of the bubble wall

surfacetension

bubble radius


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Work is in progress towards

an explanation oflarge-scale CMB anomalies

with

black holes, domain filaments,

and bubble walls


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Conclusion 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 !? Many models give a suppressed CMB low

multipoles and/or directional effects

Perhaps we are all fooled by probability it isindeed a Gaussian quantum process

Nongaussianity is an important check

Kin-Wang Ng

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