Common Origin of Warm Dark Matter & Dark Radiation

Home , Dark radiation

Manuel A. Buen-Abad w/ Raymond Co & Keisuke Harigaya arXiv: 1911.13267

24 Aug - 04 Sep 2020

1 Outline

I. Motivation II. Model III. Results IV. Outlook and Conclusions

2 I. Motivation

3 Precision Cosmology e.g.:

CMB - Planck MPS - SDSS 4 Standard Framework ΛCDM

5 However...

Experimental Tensions, e.g: Theoretical Motivations, e.g.:

⇒ ● H0 crisis: Direct > Indirect ● DM origin rich DS ○ SH0ES etc. v. Planck ● Particle Physics Problems: ○ recent reviews: 1907.10625 2001.03624 ○ Hierarchy: SUSY & WIMPs

● σ8: Direct < Indirect ○ Strong CP: axions ○ KiDS etc. v. Planck ○ ν Masses: sterile neutrinos ○ recent results: 2007.15632

6 Standard Framework

Λbeyond?CDM

7 Dark Sectors

● Dark Matter... ● … Dark Radiation... beyond! ● … also Dark Energy ?

8 Beyond ΛCDM: common paths

Dark Radiation (DR): ΔNeff Warm Dark Matter (WDM): fwdm, ∝ anr( 1/Tnr)

● CMB: peaks, damping, equality…

● MPS: increase structure & σ8 [maintain ● MPS: Free-streams ⇒ suppresses equality] structure

9 II. Model

10 Common Origin of Warm and Relativistic Decay particles

11 Common Origin of Warm and Relativistic Decay particles

12 COWaRD:

χ1⟶ χ2+φ

13 COWaRD: χ1⟶ χ2+φ

● χ1: Decaying DM ○ Unstable massive parent ⇒ ○ ρ1, Γ adec ● χ : WDM {ρ , a , f , a , ΔN } 2 1 dec wdm nr eff ○ Stable massive daughter

○ fwdm, anr ● φ: DR ○ Lightest/massless daughter

○ ΔNeff 14 {ρ1, adec, fwdm, anr, ΔNeff}

COWaRD Thermal History

15 common origin

{ρ1, adec, fwdm, anr, ΔNeff}

COWaRD Thermal History

16 {ρ1, adec, fwdm, anr, ΔNeff}

same abundance: ΔNeff fwdm

COWaRD Thermal History

17 {adec, fwdm, ΔNeff}

∝ anr ΔNeff / COWaRD Thermal History fwdm 18 {adec, fwdm, ΔNeff}

∝ ⇒ Tnr 1/anr

∝ anr ΔNeff / COWaRD Thermal History fwdm 19 WDM

COWaRD

20 WDM

∼ λFS ΔNeff/fwdm

COWaRD

21 WDM

σ8 ↔ ΔNeff ∼ λFS ΔNeff/fwdm COWaRD: anti-correlated (naive DR: correlated)

COWaRD

22 BSM COWaRD examples

χ1⟶χ2+φ: SUSY+ axions

● axino ⟶ gravitino + axion ● gravitino ⟶ axino + axion

⇒ {m1, m2, N1,ini} {adec, fwdm, ΔNeff} particle physics cosmology 23 III. Results

24 Implementation

Numerics Data

● CLASS Boltzmann solver ● CMB: Pl18 TT+TE+EE+lens ● MontePython MCMC ● BAO: 6dFGS+SDSS+BOSS ○ Small a no effect on ﬁt ⇒ assumed χ dec 1 ● No σ8 data -7 already decayed (ﬁxed adec=10 ) ⇒ ○ Fit only {ΔNeff, fwdm}

25 Numerical Results

26 ∼ λFS ΔNeff/fwdm

correlated: usual DR (ΔNeff) behavior anti-correlated: COWaRD

Numerical Results

27 Δχ2 = -1.9

CFHTLens

Numerical Results

28 IV. Outlook & Conclusions

29 Outlook

● CMB-S4: ΔNeff≥0.03 ∼ ○ COWaRD ﬁt to CMB: predicts λFS ΔNeff/fwdm

σ8(ΔNeff) ● Future work: ○ Full decay implementation (solve psd function)

30 Conclusions

Particular: COWaRD General: moral

● Theoretically motivated model ● Naive ΛCDM extensions ≠ their

● Solves σ8 tension w/o degrading CMB actual model realization!!! ﬁt, and w/o asking it to! ○ Within pheno models: ■ parameters can act differently... ● Combines DR & WDM ■ … and be related! ○ Interesting effects ○ Actual realizations can give surprising ○ Few parameters cosmology!

31 ¡Gracias!

32 Back-up slides

COWaRD: anr radiation

4 4 ρ (a ) ∼ ρ (a ) ∝ ΔN 2,nr nr φ,nr nr eff matter 3 ∝ ρ2,nr(anr) ≈ ρ2,0 fwdm

34 COWaRD: anr 4 ∼ 4 ∝ ρ2,nr(anr) ρφ,nr(anr) ΔNeff ⇒ f a ∝ ΔN 3 ∝ wdm nr eff ρ2,nr(anr) ≈ ρ2,0 fwdm

∝ ⇒ Tnr 1/anr

35 ∼ λFS ΔNeff/fwdm

σ8 ↔ ΔNeff

Naive DR: correlated COWaRD: anti-correlated

COWaRD MPS impact

36 BSM COWaRD examples

χ1⟶χ2+φ: SUSY+ axions

● axino ⟶ gravitino + axion ● gravitino ⟶ axino + axion

⇒ {m1, m2, N1,ini} {adec, fwdm, ΔNeff} particle physics cosmology 37 Other parameters: Tdec & m1/m2 38

gravitino

axino m1 & m2 39 Best Fit χ2

40 Parameter values

41 Contour Plots