Dark Energy and its connections to Neutrinos, Baryogenesis and Dark Matter Xinmin Zhang Institute of High Energy Physics, Beijing P. R. China

Concordance model of the Cosmology: Inflation    Outline of the talk I. Brief review on the constraints on the Dark Energy II. A new scenario of Dark Energy model: Quintom III. Interacting Dark Energy: a) Connection to neutrinos: Mass varying Neutrinos b) Connection to Baryogenesis: Quintessential Leptogenesis c) Connection to Dark matter: Neutralino mass varying SUSYing interacting DE: Quintessino Dark matter IV. Summary

Dark Energy: * Negative pressure:  * Smoothly distributed, (almost ) not clustering Candidates: * Cosmological constant (or vacuum Energy) But:, cosmological constant problem! * Dynamical Field: Quintessence, K-essence, Phantom etc

I. Constraints on the Dark Energy A quantity characterizing the property of Dark Energy: Equation of state: w(Z)=P/ρ For example : * Vacuum Energy: w=-1 * Quintessence: * Phantom: Using the recent 157 Supernova data published by Riess et al. astro-ph/ * At 2 σ, the cosmological constant fits well the data * Data mildly favour a running of the W across -1 Model independent analysis with the following parameterization ： 1 ， w(z)=w_0 + w_1* z 2 ， w(z)=w_1 + w_a*z/(1+z) (E.Linder)

Feng, Wang & X. Zhang Astro-ph/ Huterer & Cooray Astro-ph/

astro-ph/ , Steen Hannestad,Steen Hannestad Edvard Mortsell Probing Dark Energy with Supernovae : a concordant or a convergent model? Authors: J.-M. Virey, A. Ealet, C. Tao, A. Tilquin, A. Bonissent, D. Fouchez, P. Taxil,astro-ph/ J.-M. VireyA. EaletC. TaoA. TilquinA. Bonissent D. FouchezP. Taxil

Two comments: 1. Parameterization dependent 2. Effects of perturbations

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W 1 = 20 Astro-ph/

II. The new scenario of Dark Energy : Quintom If the running of w(Z), especially a transition across –1, confirmed in the future, big challenge to the model building * Vacuum : w=-1 * Quintessence: * Phantom: * K-essence: or but cannot across -1 (Vikman: astro-ph/ ) A new scenanio of Dark Energy : Quintom (Zhang et al. Astro-ph/ ) For ex: single scalar: multi-scalar:

Detailed study on: Two-field models of Quintom Dark Energy - Xiao-fei Zhang,Hong Li, Yunsong Piao and Xinmin Zhang I. Quintom model with two scalar fields: II. Quintom model with Phantom field and neutrino: Astro-ph/ Important: Neutrino mass vary

The constraints on the coupling of Neutrinos to DE from SN - by Li Hong, Feng Bo, Jun-Qing Xia and Xinmin Zhang, astro-ph/ Consistent with Quintom: Phantom ⊕ Neutrinos c≠0: Interacting

Recent Development on Quintom ( “ 精灵 ” ) Dark Energy Model I.A lot of recent theoretical studies on the models of Dark Energy with equation of state across -1 One example: II.Implications in CMB: W. Hu astro-ph/ R. Caldwell and Doran: astro-ph/ G. Zhao, J. Xia, M. Li, B. Feng and X. Zhang: astro-ph/ III.Different from cosmological constant, Quintessence and Phantom in the determination of the evolutions and the fate of the universe A lot of s tudies on the evolution of UNIVERSE with w across -1 just give one example: Oscillating Quintom

A.Anisimov, E. Babichev, B.A. Vikman,astro-ph/ Quintom with Single scalar field For equivalent to two fields Recall single scalar fields like Quintessence, Phantom and Kessence can not cross -1 Mingzhe Li, Bo Feng, Xinmin Zhang, hep-ph/

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Implication of Quintom dark energy in CMB G.Zhao, J. Xia, M.Li, B. Feng and X.Zhang astro-ph/

Oscillating Quintom and the Recurrent Universe: astro-ph/ Bo Feng, Minzhe Li, Yunsong Piao, Xinmin Zhang

Note: Results parametrization dependent astro-ph/

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III. Interacting Dark Energy Current data favour Quintom Quintom Dark Energy is described by dynamical scalar fields Expected also to interact with the matter directly. Open new possibilities for the detection. * Direct coupling with ordinary matter Constraint from the limits on the long-range force * Interacting with DM (Peebles et al ) * Interacting with neutrinos * Derivatively interacting with matter fields

Implications of Interacting DE I.Interacting with Neutrino: mass varying neutrinos II.Derivatively Ineracting with Lepton Current: Quintessential Leptogenesis III.Interacting with Dark Matter: mass varying Neutralino Quintessino Dark Matter

Direct couplings: Neutrino masses vary Xinmin Zhang etal. PRD68, (2003) Dark Energy and neutrinos ： Any connection between Dark Energy and neutrinos? 1.ΛCDM: 2.QCDM: If yes, very interesting: 2 of the biggest discoveries in the recent years Connections  Interactions between dark energy and neutrinos Two types couplings Derivative couplings: Quintessential Leptogenesis -M. Li, X. Wang, B. Feng, X. Zhang CPT violation Phys.Rev. D65 (2002)

Where, Corresponding the formula for the neutrino mass upper limit now is:

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New features of neutrino Dark Energy model: I.Unlike the ordinary matter the massive neutrino has equation of state II.Neutrino plays an improtant role in the evolution of the universe III.Mass varying neutrinos effects on CMB, LSS IV.Testing mass varying neutrinos with GRB V.Testing mass varying with neutrino oscillations

Cosmological evolution of Interacting Dark Energy models with massvarying neutrinos hep/ph/ Xiaojun Bi, Bo Feng, Hong Li, Xinmin Zhang

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Testing mass varying neutrino with short GRB -Hong Li, Zigao Dai, Xinmin Zhang: hep-ph/

Neutrino oscillation probes of Dark Energy D.B. Kaplan et al., PRL 93, (2003); V. Barger et al., hep-ph/ ; M. Cirelli et al., hep-ph/ Basic idea ： given by Neutrino oscillation Solar Neutrino oscillation ： (i = 1, 2, 3) Depends on the scalar potential And its coupling to neutrinos Model dependent

Connection to Baryogenesis Sakharov conditions: 1. baryon number violation 2. c and cp violation 3. out of thermal equilibrium (cpt conserving ) *Electroweak Baryogenesis *Leptogenesis *Cosmological CPT violation and generation of baryon Number asymmetry in thermal equilibrium

M.Li, X.Wang, B.Feng, X. Zhang PRD65, (2002) A. Felice, S. Nasri, M.Trodden PRD67: (2003) A. FeliceS. NasriM.Trodden M.Li & X. Zhang ， PLB573,20 (2003) In thermo equilibrium   Quintessential Baryogenesis Cohen & Kaplan The value of depends on the model of Quintessence

model ： Solution: Decoupling T ： Tracking Albrecht & Skordis PRL84,2076(2000) If B-violation is due to electroweak sphalerons T D about 100 GeV requires

Quintessential leptogenesis & neutrino mass limits Similarly: T D determined by where andwhich gives for degenerate neutrino masses: defining Cosmological limits give WMAP : SDSS :

* In the Quintessence as Dark Energy scenario, this is the minimal model for Baryogenesis in the sense that no extra particle beyond the standard model is introduced. * In ΛCDM model, with f(R): function of Ricci scalar, I.If, Einstein equation give: so, in radiation dominant Universe, II.We propose, so generating n B /s naturally! Minimal model of Baryogenesis Davoudiasl,Kitano,Kribs Murayama and Steinhardt H.Li, M.Li,X.Zhang

Connection to Dark Matter I.Interacting with Dark Matter particles such as neutralino similar to neutrino mass variation in oscillation expect neutralino mass vary : affecting detection II.SUSYing Interacting Quintessence: Quintessence : Dark Energy Quintessino: Dark Matter Unified description on dark matter and dark energy

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Quintessino As Dark Matter If susying the Quintessence: Quintessence: Q Squintessence: σ q Quintessino: Similar to : Axion, Saxion, Axino Majoron, Smajoron, Majorino If is lighter than, could serve as Dark matter Susying the following interaction (H: SU(2) doublet) gives * Prediction: long-lived charged particle: (R. Mohapatra and Zhang) (X. Bi, M. Li and Zhang)

Neutralino: Thermal Production & Non-thermal Production For ex: consider a model with extra U B-L (1) U B-L (1) broken neutrino masses & cosmic string String loop decay Jeannerot, Brandenberger &Zhang, Jan Comparison with neutralino Dark Matter Neutralino : weak interacting Quintessino: Superweak Prediction: long-lived charged particle: Quintessino: non-thermal production

Thermal production Non-thermal 1 ， 2, enhancing the parameter space 3, cold dark matter warm dark matter Weak interactions“stronger” interactions

CDM: “Nagging Problems” Prediction of cuspy dark halos Apparent prediction of too much substructures thermal Non-thermal Astrophysical explanations Lin, Huang, Zhang & Brandenberger, Particle physics PRL (2001)

Summary I.Quintom Dark Energy Models: Current data consistant with the cosmological constant but mildly favour the Quintom: a dynamical dark energy with Equation of state evolving and crossing -1 need more data and model building of Quintom dark energy II.Interacting Dark Energy Models: Interesting implications in cosmology: mass varying neutrino; quintessential leptogenesis; quintessino dark matter Open up a possibility of detecting dark energy non-gravitationally

Thanks !