Baryons, Dark Matter, and Light Scalars Takeshi Kobayashi (SISSA) - - PowerPoint PPT Presentation

Baryons, Dark Matter, and Light Scalars

based on arXiv:1612.04824, 1708.00015 with A. De Simone, V. Iršič, S. Liberati, R. Murgia, M. Viel

Takeshi Kobayashi (SISSA)

YKIS 2018a, YITP

LIGHT SCALARS

• are ubiquitous in extensions of the Standard Model

e.g. QCD axion, string axiverse

Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 Svrcek, Witten ’06 Arvanitaki, Dimopoulos, Dubovsky, Kaloper, March-Russell ’09

LIGHT SCALARS

• are ubiquitous in extensions of the Standard Model

e.g. QCD axion, string axiverse

Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 Svrcek, Witten ’06 Arvanitaki, Dimopoulos, Dubovsky, Kaloper, March-Russell ’09

• can be dark matter

may even solve the small-scale “crisis” of CDM, if ultralight (fuzzy)

Hu, Barkana, Gruzinov ’00

LIGHT SCALARS

strong constraints from cosmology

• are ubiquitous in extensions of the Standard Model

e.g. QCD axion, string axiverse

Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 Svrcek, Witten ’06 Arvanitaki, Dimopoulos, Dubovsky, Kaloper, March-Russell ’09

• can be dark matter

may even solve the small-scale “crisis” of CDM, if ultralight (fuzzy)

Hu, Barkana, Gruzinov ’00

LIGHT SCALARS

• can generate the baryon asymmetry of the Universe

strong constraints from cosmology

• are ubiquitous in extensions of the Standard Model

e.g. QCD axion, string axiverse

Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 Svrcek, Witten ’06 Arvanitaki, Dimopoulos, Dubovsky, Kaloper, March-Russell ’09

• can be dark matter

may even solve the small-scale “crisis” of CDM, if ultralight (fuzzy)

Hu, Barkana, Gruzinov ’00

LIGHT SCALARS

• can generate the baryon asymmetry of the Universe

strong constraints from cosmology

• are ubiquitous in extensions of the Standard Model

e.g. QCD axion, string axiverse

Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 Svrcek, Witten ’06 Arvanitaki, Dimopoulos, Dubovsky, Kaloper, March-Russell ’09

• can be dark matter

may even solve the small-scale “crisis” of CDM, if ultralight (fuzzy)

Hu, Barkana, Gruzinov ’00

Today’s talk

Cosmological Constraints on Ultralight Scalar DM

arXiv:1708.00015 TK, Murgia, De Simone, Iršič, Viel

PECULIAR FEATURE OF LIGHT SCALAR DM

Wave nature of the scalar field is prominent on small scales (< de Broglie wavelength).

Khlopov, Malomed, Zeldovich ’85 Nambu, Sasaki ’90 Ratra ’91

PECULIAR FEATURE OF LIGHT SCALAR DM

rµrµφ = m2φ

Klein-Gordon eq.

Gµν = 8πG Tµν

Einstein’s eq.

∂2Φ a2 = 4πGρ − 3 2H2 ˙ ρ + 3Hρ + ∂i(ρvi) a = 0

Euler eq. continuity eq. Poisson eq. Switching to a fluid description in a perturbed FRW universe,

+ 1 2a3m2 ∂i ✓∂2√ρ √ρ ◆ ˙ vi + Hvi + vj∂jvi a = −∂iΦ a

Wave nature of the scalar field is prominent on small scales (< de Broglie wavelength).

Khlopov, Malomed, Zeldovich ’85 Nambu, Sasaki ’90 Ratra ’91

0.1 1 10 100 0.2 0.4 0.6 0.8 1.0

F = 0.05 F = 0.1 F = 0.2 F = 0.4 F = 0.6 F = 0.8 F = 1

P(φ+c)

m0

(k) P(c)

m0(k)

k [Mpc-1]

Ultralight scalar DM has been expected to solve the small-scale “problems” of CDM (e.g. missing-satellite, too-big-to-fail, core-cusp).

Hui, Ostriker, Tremaine, Witten ’16 Hu, Barkana, Gruzinov ’00

m = 10−22 eV

SUPPRESSION OF LINEAR MATTER POWER

LYMAN-α FOREST

figure from Springel, Frenk, White astro-ph/0604561 image courtesy of Vid Iršič

LYMAN-α CONSTRAINT

10−23 10−22 10−21 10−20

m [eV]

0.0 0.2 0.4 0.6 0.8 1.0

F

3 σ C. L. 2 σ C. L.

scalar DM fraction scalar mass

IMPLICATIONS FOR MISSING SATELLITES

Estimate of Milky Way satellites suggests there is very little room for ultralight DM to solve the problem.

10−23 10−22 10−21 10−20

m [eV]

0.0 0.2 0.4 0.6 0.8 1.0

F

3 σ C. L. (Lyman-α forest) 2 σ C. L. (Lyman-α forest) ”solution” to missing satellite

• Further constraints from CMB and DM isocurvature

perturbations

• The constraints apply to generic theories that contain

ultralight scalar fields

COMMENTS

Baryon Asymmetry from a Light Scalar: Geometric Baryogenesis

arXiv:1612.04824 Liberati, TK, De Simone

BASIC ASSUMPTIONS

• existence of a scalar with an (approximate) shift symmetry
• the scalar is allowed to couple to various fields through

shift-symmetric operators

SHIFT-SYMMETRIC ACTION

+ φ × ∂µ( ) L √−g = −1 2(∂φ)2 + · · ·

SHIFT-SYMMETRIC ACTION

+ φ × ∂µ( ) L √−g = −1 2(∂φ)2 + · · ·

SHIFT-SYMMETRIC ACTION

+ φ × ∂µ( ) L √−g = −1 2(∂φ)2 + · · · φF ˜ F

with gauge fields:

SHIFT-SYMMETRIC ACTION

+ φ × ∂µ( ) L √−g = −1 2(∂φ)2 + · · · φF ˜ F

with gauge fields:

/ φ rµjµ

B

(for SU(2))

SHIFT-SYMMETRIC ACTION

+ φ × ∂µ( ) L √−g = −1 2(∂φ)2 + · · · φF ˜ F

with gauge fields:

φ G

with gravity: (Gauss-Bonnet term )

G = R2 − 4RµνRµν + RµνρσRµνρσ / φ rµjµ

B

(for SU(2))

SHIFT-SYMMETRIC ACTION

+ φ × ∂µ( ) L √−g = −1 2(∂φ)2 + · · · φF ˜ F

with gauge fields:

φ G

with gravity: (Gauss-Bonnet term )

G = R2 − 4RµνRµν + RµνρσRµνρσ

Gravitational couplings are special in that they induce coherent effects to the scalar in an expanding universe.

/ φ rµjµ

B

(for SU(2))

SHIFT-SYMMETRIC ACTION

+ φ × ∂µ( ) L √−g = −1 2(∂φ)2 + · · · φF ˜ F

with gauge fields:

φ G

with gravity: (Gauss-Bonnet term )

G = R2 − 4RµνRµν + RµνρσRµνρσ

Gravitational couplings are special in that they induce coherent effects to the scalar in an expanding universe.

/ φ rµjµ

B

(for SU(2))

SHIFT-SYMMETRIC ACTION

+ φ × ∂µ( ) L √−g = −1 2(∂φ)2 + · · · φF ˜ F

with gauge fields:

φ G

with gravity: (Gauss-Bonnet term )

G = R2 − 4RµνRµν + RµνρσRµνρσ

Gravitational couplings are special in that they induce coherent effects to the scalar in an expanding universe.

/ φ rµjµ

B

(for SU(2))

L pg = 1 2(∂φ)2 + φ M G + φ f rµjµ

B + · · ·

non-gravitational or mass dim. ≥ 6

GEOMETRIC BARYOGENESIS

}

L pg = 1 2(∂φ)2 + φ M G + φ f rµjµ

B + · · ·

non-gravitational or mass dim. ≥ 6

GEOMETRIC BARYOGENESIS

}

φ f rµjµ

B =

˙ φ f nB

In a flat FRW universe

G = 24(H4 + H2 ˙ H), ˙ φ = 8H3 M ,

→ relative shift in baryon/antibaryon spectra → baryogenesis even in equilibrium (due to CPT violation)

Cohen, Kaplan ’87

nB s ∼ T 5 fMM 3

p

L pg = 1 2(∂φ)2 + φ M G + φ f rµjµ

B + · · ·

non-gravitational or mass dim. ≥ 6

GEOMETRIC BARYOGENESIS

}

φ f rµjµ

B =

˙ φ f nB

In a flat FRW universe

G = 24(H4 + H2 ˙ H), ˙ φ = 8H3 M ,

→ relative shift in baryon/antibaryon spectra → baryogenesis even in equilibrium (due to CPT violation)

Cohen, Kaplan ’87

nB s ∼ T 5 fMM 3

p

spontaneous breaking of Lorentz invariance due to cosmic expansion baryon asymmetry

φ

too much axion DM

11 12 13 14 15 16 17 18 11 12 13 14 15 16 17 18 log10( f [GeV]) log10(Tdec [GeV])

exceeds Planck bound

• n inflation scale

s i g n i fi c a n t b a r y

• n

b a c k r e a c t i

• n

too much DM isocurvature

M = 10

1 8

GeV M = 10

1 4

GeV M = 10

1

GeV

m = 10−22 eV φ? = f

e.g.,

L pg = 1 2(∂φ)2 + φ M G + φ f rµjµ

B 1

2m2φ2 + · · ·

GEOMETRIC BARYOGENESIS WITH AN ULTRALIGHT SCALAR

spoils Lyman-α forest too much axion DM

11 12 13 14 15 16 17 18 11 12 13 14 15 16 17 18 log10( f [GeV]) log10(Tdec [GeV])

exceeds Planck bound

• n inflation scale

s i g n i fi c a n t b a r y

• n

b a c k r e a c t i

• n

too much DM isocurvature

M = 10

1 8

GeV M = 10

1 4

GeV M = 10

1

GeV

m = 10−22 eV φ? = f

e.g.,

L pg = 1 2(∂φ)2 + φ M G + φ f rµjµ

B 1

2m2φ2 + · · ·

GEOMETRIC BARYOGENESIS WITH AN ULTRALIGHT SCALAR

spoils Lyman-α forest too much axion DM

11 12 13 14 15 16 17 18 11 12 13 14 15 16 17 18 log10( f [GeV]) log10(Tdec [GeV])

exceeds Planck bound

• n inflation scale

s i g n i fi c a n t b a r y

• n

b a c k r e a c t i

• n

too much DM isocurvature

M = 10

1 8

GeV M = 10

1 4

GeV M = 10

1

GeV

m = 10−22 eV φ? = f

e.g.,

L pg = 1 2(∂φ)2 + φ M G + φ f rµjµ

B 1

2m2φ2 + · · ·

GEOMETRIC BARYOGENESIS WITH AN ULTRALIGHT SCALAR Alternatively, geometric baryogenesis can also be driven by the QCD axion!

SUMMARY

• Light scalars, if present in the theory, have significant

impact in cosmology

• CANNOT solve the small-scale issues without spoiling

the Lyman-α forest

• CAN generate the baryon asymmetry of our Universe!