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

Baryons, Dark Matter, and Light Scalars Takeshi Kobayashi (SISSA) based on arXiv:1612.04824, 1708.00015 with A. De Simone, V. Ir š i č , S. Liberati, R. Murgia, M. Viel YKIS 2018a, YITP

LIGHT SCALARS • are ubiquitous in extensions of the Standard Model e.g. QCD axion, string axiverse Svrcek, Witten ’06 Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 Arvanitaki, Dimopoulos, Dubovsky, Kaloper, March-Russell ’09

LIGHT SCALARS • are ubiquitous in extensions of the Standard Model e.g. QCD axion, string axiverse Svrcek, Witten ’06 Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 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 • are ubiquitous in extensions of the Standard Model e.g. QCD axion, string axiverse Svrcek, Witten ’06 Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 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 strong constraints from cosmology

LIGHT SCALARS • are ubiquitous in extensions of the Standard Model e.g. QCD axion, string axiverse Svrcek, Witten ’06 Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 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 strong constraints from cosmology • can generate the baryon asymmetry of the Universe

LIGHT SCALARS • are ubiquitous in extensions of the Standard Model e.g. QCD axion, string axiverse Svrcek, Witten ’06 Peccei, Quinn ’77 Weinberg ’78 Wilczek ’78 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 strong constraints from cosmology Today’s talk • can generate the baryon asymmetry of the Universe

Cosmological Constraints on Ultralight Scalar DM arXiv:1708.00015 TK, Murgia, De Simone, Ir š i č , 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 Wave nature of the scalar field is prominent on small scales (< de Broglie wavelength). Khlopov, Malomed, Zeldovich ’85 Nambu, Sasaki ’90 Ratra ’91 Klein-Gordon eq. Einstein’s eq. r µ r µ φ = m 2 φ G µ ν = 8 π G T µ ν Switching to a fluid description in a perturbed FRW universe, ✓ ∂ 2 √ ρ ◆ v i + Hv i + v j ∂ j v i = − ∂ i Φ 1 Euler eq. 2 a 3 m 2 ∂ i + ˙ √ ρ a a ρ + 3 H ρ + ∂ i ( ρ v i ) continuity eq. ˙ = 0 a ∂ 2 Φ = 4 π G ρ − 3 Poisson eq. 2 H 2 a 2

SUPPRESSION OF LINEAR MATTER POWER P ( φ +c) ( k ) m0 1.0 P (c) m0 ( k ) 0.8 F = 0.05 F = 0.1 0.6 F = 0.2 m = 10 − 22 eV F = 0.4 0.4 F = 0.6 F = 0.8 0.2 F = 1 k [Mpc -1 ] 0.1 1 10 100 Ultralight scalar DM has been expected to solve the small-scale “problems” of CDM (e.g. missing-satellite, too-big-to-fail, core-cusp). Hu, Barkana, Gruzinov ’00 Hui, Ostriker, Tremaine, Witten ’16

LYMAN- α FOREST figure from Springel, Frenk, White astro-ph/0604561 image courtesy of Vid Ir š i č

LYMAN- α CONSTRAINT 1.0 3 σ C. L. 2 σ C. L. 0.8 scalar DM fraction 0.6 F 0.4 0.2 0.0 10 − 23 10 − 22 10 − 21 10 − 20 m [eV] scalar mass

IMPLICATIONS FOR MISSING SATELLITES Estimate of Milky Way satellites suggests 1.0 3 σ C. L. (Lyman- α forest) 2 σ C. L. (Lyman- α forest) ”solution” to missing satellite 0.8 0.6 F 0.4 0.2 0.0 10 − 23 10 − 22 10 − 21 10 − 20 m [eV] there is very little room for ultralight DM to solve the problem.

COMMENTS • Further constraints from CMB and DM isocurvature perturbations • The constraints apply to generic theories that contain ultralight scalar fields

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

SHIFT-SYMMETRIC ACTION √− g = − 1 L 2( ∂φ ) 2 + φ × ∂ µ ( ) + · · ·

SHIFT-SYMMETRIC ACTION √− g = − 1 L 2( ∂φ ) 2 + φ × ∂ µ ( ) + · · · with gauge fields: φ F ˜ F

SHIFT-SYMMETRIC ACTION √− g = − 1 L 2( ∂φ ) 2 + φ × ∂ µ ( ) + · · · with gauge fields: ( for SU(2) ) / φ r µ j µ φ F ˜ F B

SHIFT-SYMMETRIC ACTION √− g = − 1 L 2( ∂φ ) 2 + φ × ∂ µ ( ) + · · · with gauge fields: ( for SU(2) ) / φ r µ j µ φ F ˜ F B with gravity: φ G G = R 2 − 4 R µ ν R µ ν + R µ νρσ R µ νρσ (Gauss-Bonnet term )

SHIFT-SYMMETRIC ACTION √− g = − 1 L 2( ∂φ ) 2 + φ × ∂ µ ( ) + · · · with gauge fields: ( for SU(2) ) / φ r µ j µ φ F ˜ F B with gravity: φ G G = R 2 − 4 R µ ν R µ ν + R µ νρσ R µ νρσ (Gauss-Bonnet term ) Gravitational couplings are special in that they induce coherent effects to the scalar in an expanding universe.

SHIFT-SYMMETRIC ACTION √− g = − 1 L 2( ∂φ ) 2 + φ × ∂ µ ( ) + · · · with gauge fields: ( for SU(2) ) / φ r µ j µ φ F ˜ F B with gravity: φ G G = R 2 − 4 R µ ν R µ ν + R µ νρσ R µ νρσ (Gauss-Bonnet term ) Gravitational couplings are special in that they induce coherent effects to the scalar in an expanding universe.

SHIFT-SYMMETRIC ACTION √− g = − 1 L 2( ∂φ ) 2 + φ × ∂ µ ( ) + · · · with gauge fields: ( for SU(2) ) / φ r µ j µ φ F ˜ F B with gravity: φ G G = R 2 − 4 R µ ν R µ ν + R µ νρσ R µ νρσ (Gauss-Bonnet term ) Gravitational couplings are special in that they induce coherent effects to the scalar in an expanding universe.

GEOMETRIC BARYOGENESIS p� g = � 1 L 2( ∂φ ) 2 + φ M G + φ f r µ j µ B + · · · } non-gravitational or mass dim. ≥ 6

GEOMETRIC BARYOGENESIS p� g = � 1 L 2( ∂φ ) 2 + φ M G + φ f r µ j µ B + · · · } non-gravitational or mass dim. ≥ 6 In a flat FRW universe ˙ φ = 8 H 3 φ φ G = 24( H 4 + H 2 ˙ f r µ j µ ˙ H ) , f n B M , B = � → relative shift in baryon/antibaryon spectra → baryogenesis even in equilibrium (due to CPT violation) T 5 n B Cohen, Kaplan ’87 ∼ fMM 3 s p

GEOMETRIC BARYOGENESIS p� g = � 1 L 2( ∂φ ) 2 + φ M G + φ f r µ j µ B + · · · } non-gravitational or mass dim. ≥ 6 In a flat FRW universe ˙ φ = 8 H 3 φ φ G = 24( H 4 + H 2 ˙ f r µ j µ ˙ H ) , f n B M , B = � spontaneous breaking of φ Lorentz invariance due to baryon asymmetry → relative shift in baryon/antibaryon spectra cosmic expansion → baryogenesis even in equilibrium (due to CPT violation) T 5 n B Cohen, Kaplan ’87 ∼ fMM 3 s p

GEOMETRIC BARYOGENESIS WITH AN ULTRALIGHT SCALAR p� g = � 1 B � 1 L 2( ∂φ ) 2 + φ M G + φ 2 m 2 φ 2 + · · · f r µ j µ 18 too much DM isocurvature e.g., m = 10 − 22 eV 17 exceeds Planck bound on inflation scale 16 φ ? = f log 10 ( T dec [ GeV ]) GeV 8 1 M = 10 15 GeV 4 1 M = 10 n o GeV 14 0 i 1 t M = 10 c a t e n r k a c c fi a 13 b i n g n i o s y r a 12 b too much axion DM 11 11 12 13 14 15 16 17 18 log 10 ( f [ GeV ])

GEOMETRIC BARYOGENESIS WITH AN ULTRALIGHT SCALAR p� g = � 1 B � 1 L 2( ∂φ ) 2 + φ M G + φ 2 m 2 φ 2 + · · · f r µ j µ 18 too much DM isocurvature e.g., m = 10 − 22 eV 17 exceeds Planck bound on inflation scale 16 φ ? = f log 10 ( T dec [ GeV ]) GeV 8 1 M = 10 15 GeV 4 1 M = 10 n o GeV 14 0 i 1 t M = 10 c a t e spoils Lyman- α forest n r k a c c fi a 13 b i n g n i o s y r a 12 b too much axion DM 11 11 12 13 14 15 16 17 18 log 10 ( f [ GeV ])

GEOMETRIC BARYOGENESIS WITH AN ULTRALIGHT SCALAR p� g = � 1 B � 1 L 2( ∂φ ) 2 + φ M G + φ 2 m 2 φ 2 + · · · f r µ j µ 18 too much DM isocurvature e.g., m = 10 − 22 eV 17 exceeds Planck bound on inflation scale 16 φ ? = f log 10 ( T dec [ GeV ]) GeV 8 1 Alternatively, geometric baryogenesis M = 10 15 GeV 4 1 M = 10 can also be driven by the QCD axion! n o GeV 14 0 i 1 t M = 10 c a t e spoils Lyman- α forest n r k a c c fi a 13 b i n g n i o s y r a 12 b too much axion DM 11 11 12 13 14 15 16 17 18 log 10 ( f [ GeV ])

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!