1. J.W. Ustron 20091 UN B. Grzadkowski J.W - cosmology

2. J.W. Ustron 20092 UV completion Basic idea New type of physics such that It is conformally invariant in the IR Asymptotically free in the UV It interacts weakly with the SM Banks-Zaks ( BZ ) phase Asymptotically free Unparticle ( U ) phase Conformally invariant Heavy Mediators

3. J.W. Ustron 20093 UV completion BZ phase Unparticle phase The history of unparticles is dark and unknown but it is nevertheless divided by theoreticians into three periods The first about which we know nothing The second about which we know almost as much as about the first And the third which succeeded the first two (with apologies to A. Averchenko) The new physics sector has two relevant scales:

4. J.W. Ustron 20094 To make calculations one needs: Rather unique collider signatures No experimental motivation whatsoever Can be used to understand how unusual types of new physics can affect cosmic evolution That follows from conformal invariance

5. J.W. Ustron 20095 Thermodynamics Conformal invariance:  has a non-trivial IR zero at g=g * The trace of the energy momentum tensor vanishes in the IR g*g* g*g*  = anomalous dimension of F 2

6. J.W. Ustron 20096 ) For available models g NP » 100 In the UV: asymptotically free )  / T 4 to leading order

7. J.W. Ustron 20097 SM-NP interactions Equilibrium, freeze-out and thaw-in Standard approach: use the Boltzmann equation Equilibrium as long as  > H  = H at T = T f Less standard approach: use the Kubo equation … yields the same result … but does not need to introduce the unparticle distribution function

8. J.W. Ustron 20098 NP SM SM’ NP’ Energy = E SM 4-momentum=K SM Energy = E NP 4-momentum=K NP Energy = E 4 mom. = K Energy = E’ SM 4-momentum=K’ SM Energy = E’ NP 4-momentum=K’ NP Energy = E’ 4 mom. = K’

9. J.W. Ustron 20099 Only need a order of magnitude estimate for  :

10. J.W. Ustron 200910 d SM + d NP > 4.5 ) freeze-out d SM + d NP < 4.5 ) thaw-in  > H: coupled  < H: decoupled  ' H ) T = T f

11. J.W. Ustron 200911 SN-NP coupling/decoupling Blue: T f 2 U phase Red: SM-NP coupled No-color: T f < v We assume that SP and NP were in equillibrium as T ! 1

12. J.W. Ustron 200912 Unparticle effects on BBN If SM-NP were in equilibrium and then decoupled, T SM and T NP can be related using entropy conservation:

13. J.W. Ustron 200913 If SM-NP remain in equilibrium during BBN: g IR < 0.3 NP contribution to  mimics that of additional ’s So unparticle models should exhibit conformal invariance with a small number of RDF in the IR. Unaware of an explicit model with this property

14. J.W. Ustron 200914 Comments Strongly coupled new physics can lead to  /H » T n (n positive or negative) ) A variety o freeze-out and thaw-in scenarios are viable ) BBN generates strong constraints on the NP. Even for the “normal” decoupling scenarios (n>0) the BBN constraint is significant: g IR 100 Unparticle models also suffer from potential theoretical problems: the coupling to the SM necessarily breaks conformal invariance. If this effect is strong the above arguments do not apply … but then the experimental signatures are particle-like