Neutrino and Neutrino and Cosmology Cosmology Dept. of Physics - - PowerPoint PPT Presentation

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Neutrino and Neutrino and Cosmology Cosmology Dept. of Physics - - PowerPoint PPT Presentation

Feb 02, 2024 271 likes •684 views

Neutrino and Neutrino and Cosmology Cosmology Dept. of Physics and Astrophysics Dept. of Physics and Astrophysics Nagoya University Nagoya University Naoshi SUGIYAMA Naoshi SUGIYAMA Brief brief review of thermal Brief brief review of

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SLIDE 1

Neutrino and Neutrino and Cosmology Cosmology

  • Dept. of Physics and Astrophysics
  • Dept. of Physics and Astrophysics

Nagoya University Nagoya University Naoshi SUGIYAMA Naoshi SUGIYAMA

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SLIDE 2

Brief brief review of thermal Brief brief review of thermal history of the Universe history of the Universe

  • Useful Conversion

Useful Conversion

  • Temperature 1eV ~ 10

Temperature 1eV ~ 104

4K

K Present epoch 2.725K~10 Present epoch 2.725K~10-

  • 4

4eV

eV Recombination 3000K~0.1eV Recombination 3000K~0.1eV

  • Redshift 1+z=T/2.725K

Redshift 1+z=T/2.725K

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SLIDE 3
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SLIDE 4

1TeV 1GeV 1MeV 1KeV 1MeV 1eV 1meV QCD Phase Transitions Big Bang Nucleosynthesis Neutrino Decoupling e+-e- pair annihilation Recombination Present Electro-weak Matter-Radiation Equality Epoch

Thermal History of the Universe Thermal History of the Universe

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SLIDE 5
  • After Inflation, the Universe is dominated by

After Inflation, the Universe is dominated by Radiation (Massless Components) Radiation (Massless Components)

  • At T=1MeV, neutrinos are decupled from thermal

At T=1MeV, neutrinos are decupled from thermal bath bath

  • At T=500keV, positrons and electrons are pair

At T=500keV, positrons and electrons are pair-

  • annihilated.

annihilated.

  • Photons are produced, and photon temperature

Photons are produced, and photon temperature increases: Tphoton > Tneutrinos increases: Tphoton > Tneutrinos

  • At 1MeV~100keV, Primordial Nucleosynthesis

At 1MeV~100keV, Primordial Nucleosynthesis

  • At 1eV(z=24000

At 1eV(z=24000Ω ΩM

Mh

h2

2), radiation and matter

), radiation and matter densities become equal: equality epoch. Since densities become equal: equality epoch. Since then, the Universe is dominated by Matter. then, the Universe is dominated by Matter.

  • Recombination takes place at 0.1eV (z=1089)

Recombination takes place at 0.1eV (z=1089)

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SLIDE 6
  • 1. What is the role of Neutrios on
  • 1. What is the role of Neutrios on

Observational Cosmology? Observational Cosmology?

  • Neutrinos were mostly massless through history

Neutrinos were mostly massless through history

  • Until T ~m

Until T ~mν

ν, massless

, massless

  • e.g., 0.1eV

e.g., 0.1eV roughly corresponds to 1000K , roughly corresponds to 1000K , which is after (yet close) to the recombination which is after (yet close) to the recombination epoch, 3000K. epoch, 3000K. Neutrinos are Radiation Component Neutrinos are Radiation Component

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SLIDE 7
  • On top of photons, neutrinos consist of radiation

On top of photons, neutrinos consist of radiation component component

  • Modify (if change the number of family)

Modify (if change the number of family)

  • Exp

Expansion Rate of the Universe=Hubble

ansion Rate of the Universe=Hubble Parameter Parameter

  • Primordial Nucleosynthesis

Primordial Nucleosynthesis

  • Matter Radiation Equality Epoch

Matter Radiation Equality Epoch

  • Temperature Anisotropies of Cosmic Microwave

Temperature Anisotropies of Cosmic Microwave Background (CMB) Background (CMB)

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SLIDE 8

Evolution of the Universe Evolution of the Universe

Friedmann Equation Friedmann Equation: : Einstein Equation with homogeneity & isotropy Einstein Equation with homogeneity & isotropy Energy Energy-

  • Momentum Conservation

Momentum Conservation

2 2 2 ) 1 ( 3 2 2 2

3 / , / , / Const. Hubble : , 8 / 3 radiation) 1/3 matter, for ( / : 3 3 8 H H K H G H w p w a a K G H a a

K c c w Matter Radiation

Λ ≡ Ω − = Ω ≡ Ω = = ≡ ∝ + = Λ + − = ≡          

Λ + −

  • ρ

ρ π ρ ρ ρ ρ ρ ρ ρ π

ν γ

ρ ρ ρ + ≡

Radiation

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SLIDE 9

log (density)

  • log T

Present epoch Radiation Matter Matter-radiation equality: Matter Dominant Radiation Dominant

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SLIDE 10

log (density)

  • log T

Present epoch Radiation Matter Matter-radiation equality: Matter Dominant Radiation Dominant Increase Neutrino densities (family) Increase Neutrino densities (family)

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SLIDE 11

Constraints from Big Bang Constraints from Big Bang Nucleosysnthesis Nucleosysnthesis

Expansion Rate (Hubble Parameter) depends on Effective Neutrino Number, Neff Change the predicted abundances of light elements Change the predicted abundances of light elements

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SLIDE 12

Larger Neff → Higher Expansion → Neutrons were decoupled from Chemical Equilibrium Early

  • e

p n e p n + ↔ + + + ↔ ν ν

Larger number of Neutrons were left Larger amount of Helium were left

Time n abundance

Large Neff

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SLIDE 13
  • Observational Abundances of

Observational Abundances of 4

4He, D,

He, D, 3

3He,

He, 7

7Li

Li

  • Determination of

Determination of Ω ΩB

Bh

h2

2 = 0.023

= 0.023± ±0.001 from Cosmic 0.001 from Cosmic Microwave Background Anisotropies Microwave Background Anisotropies Compare Theoretical Prediction with Compare Theoretical Prediction with

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SLIDE 14

N Neff

eff=3

=3 N Neff

eff=2

=2 N Neff

eff=4

=4 CMB

Tytler et al. Phys.Scripta (2000)

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SLIDE 15

Life is not so Simple: Life is not so Simple: Some Caveats Some Caveats

  • Observations were not consistent with each other

Observations were not consistent with each other

  • Treatments of Systematics are Complicated (Effect of

Treatments of Systematics are Complicated (Effect of stellar absorptions etc.) stellar absorptions etc.) Cheating? Cheating?

  • Neutron Life Time:

Neutron Life Time: Used to be Used to be 885.7 885.7 ± ± 0.8 0.8, but new measurement: , but new measurement: 878.5 878.5± ±0.7(stat) 0.7(stat) ± ±0.3(sys) 0.3(sys) ( (Serebrov, et al., (2005)) Serebrov, et al., (2005)) Shorter Life time Shorter Life time -

  • > Neutron Decoupling from

> Neutron Decoupling from Chemical equaillibrium becomes later Chemical equaillibrium becomes later -

  • > Less

> Less Neutrons are left Neutrons are left -

  • > Less Hellium Abundance

> Less Hellium Abundance

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SLIDE 16

Life is not so Simple: Life is not so Simple: Some Caveats Some Caveats

  • Observations were not consistent with each other

Observations were not consistent with each other

  • Treatments of Systematics are Complicated (Effect of

Treatments of Systematics are Complicated (Effect of stellar absorptions etc.) stellar absorptions etc.) Cheating? Cheating?

  • Neutron Life Time:

Neutron Life Time: Used to be 885.7 Used to be 885.7 ± ± 0.8, but new measurement: 0.8, but new measurement: 878.5 878.5± ±0.7(stat) 0.7(stat) ± ±0.3(sys) ( 0.3(sys) (Serebrov, et al., (2005)) Serebrov, et al., (2005)) Shorter Life time Shorter Life time -

  • > Neutron Decoupling from

> Neutron Decoupling from Chemical equaillibrium becomes later Chemical equaillibrium becomes later -

  • > Less

> Less Neutrons are left Neutrons are left -

  • > Less Hellium Abundance

> Less Hellium Abundance

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SLIDE 17

Helium Abundance History

WMAP Observations Courtesy from M. Kawasaki

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SLIDE 18

Life is not so Simple: Life is not so Simple: Some Caveats Some Caveats

  • Observations were not consistent with each other

Observations were not consistent with each other

  • Treatments of Systematics are Complicated (Effect of

Treatments of Systematics are Complicated (Effect of stellar absorptions etc.) stellar absorptions etc.) Cheating? Cheating?

  • Neutron Life Time:

Neutron Life Time: Used to be 885.7 Used to be 885.7 ± ± 0.8, but new measurement: 0.8, but new measurement: 878.5 878.5± ±0.7(stat) 0.7(stat) ± ±0.3(sys) ( 0.3(sys) (Serebrov, et al., (2005)) Serebrov, et al., (2005)) Shorter Life time Shorter Life time -

  • > Neutron Decoupling from

> Neutron Decoupling from Chemical equaillibrium becomes later Chemical equaillibrium becomes later -

  • > Less

> Less Neutrons are left Neutrons are left -

  • > Less Hellium Abundance

> Less Hellium Abundance

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SLIDE 19

Mathews et al (2005)

0.4% Neutron Life Time Dependence

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SLIDE 20

Constraints from Cosmic Microwave Constraints from Cosmic Microwave Background Anisotropies Background Anisotropies

  • Increase N

Increase Neff

eff, pushes matter

, pushes matter-

  • radiation equality

radiation equality at the later epoch, which modifies the peak at the later epoch, which modifies the peak heights and locations of CMB spectrum. heights and locations of CMB spectrum.

  • Additional neutrino species alters the damping

Additional neutrino species alters the damping tail on high tail on high l l’ ’s. s.

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SLIDE 21

多重極モーメント

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SLIDE 22

Measure the family number at z=1000

CMB Angular Power Spectrum Theoretical Prediction

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SLIDE 23
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SLIDE 24
  • P. Serpico et al., (2004)
  • A. Cuoco et al., (2004)
  • P. Crotty et al., (2003)
  • S. Hannestad, (2003)
  • V. Barger et al., (2003)
  • R. Cyburt et al. (2005)
  • E. Pierpaoli (2003)
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SLIDE 25
  • 2. How Neutrino Mass Affect?
  • 2. How Neutrino Mass Affect?
  • Present Density Parameter

Present Density Parameter

  • Neutrino Components prevent galaxy scale structure

Neutrino Components prevent galaxy scale structure to be formed due to their kinetic energy to be formed due to their kinetic energy

  • Constraints from Large Scale Structure

Constraints from Large Scale Structure

  • Change the matter

Change the matter-

  • radiation ratio near the

radiation ratio near the recombination epoch, if m ~ a few eV recombination epoch, if m ~ a few eV

  • Constraints from Cosmic Microwave Background

Constraints from Cosmic Microwave Background (Ihikawa (Ihikawa’ ’s Talk) s Talk)

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SLIDE 26

Large Structure Formation Large Structure Formation

  • Self Gravity of Cold Dark Matter forms the

Self Gravity of Cold Dark Matter forms the structure structure

  • Comparison between Numerical Simulation

Comparison between Numerical Simulation and Observations are Superb and Observations are Superb

  • Power Spectrum (matter distribution in k

Power Spectrum (matter distribution in k-

  • space)

space)

  • btained by Cold Dark Matter fluctuations fits
  • btained by Cold Dark Matter fluctuations fits

very well to the data very well to the data

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SLIDE 27

Numerical Simulation of Large Scale Structure

1 Billion Light Years

Courtesy by Naoki Yoshida

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SLIDE 28

Large Scale Structure of the Universe Large Scale Structure of the Universe

Filament Structure Void Cluster of Galaxies

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SLIDE 29

Large Scale Strucutre: One dot is a Galaxy!

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SLIDE 30
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SLIDE 31

Sloan Digital Sky Survey, NAOJ 4D2U project

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SLIDE 32

Wave number Power Spectrum Sloan Digital Sky Survey Data Solid Line: Cold Dark Matter

Tegmark et al. 2004

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SLIDE 33

Cold Dark Matter Neutrino as Dark Matter (Hot Dark Matter)

Numerical Simulation, at z=10

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SLIDE 34

Cold Dark Matter Neutrino as Dark Matter (Hot Dark Matter)

Numerical Simulation, at present

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SLIDE 35
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SLIDE 36
  • Neutrinos cannot be Dark Matter (Hot Dark

Neutrinos cannot be Dark Matter (Hot Dark Matter) since Galaxy scale structure cannot be Matter) since Galaxy scale structure cannot be formed! formed!

  • Even small fraction of Neutrino component

Even small fraction of Neutrino component with Cold Dark Matter causes Problem with Cold Dark Matter causes Problem

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SLIDE 37

small scales large scale Half of DM is Neutrinos

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SLIDE 38

Set Constraints on Neutrino Set Constraints on Neutrino Mass and Neff Mass and Neff

WMAP 3yr Data paper by Spergel et al. WMAP 3yr Data paper by Spergel et al.

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SLIDE 39

Summary Summary

  • Cosmology can set the most stringent

Cosmology can set the most stringent constraints on the properties of Neutrinos: # of constraints on the properties of Neutrinos: # of Species, and Masses Species, and Masses

  • Still we have some room for improvement, for

Still we have some room for improvement, for example Polarization of CMB Anisotropies example Polarization of CMB Anisotropies

  • PLANCK (2008) or Future Satellite

PLANCK (2008) or Future Satellite