Implications of the Bicep2 Results (if the interpretation is correct) Antonio Riotto Geneva University & CAP

Transcription

1 Implications of the Bicep2 Results (if the interpretation is correct) Antonio Riotto Geneva University & CAP La Sapienza, Roma, 12/6/2014

2 Plan of the talk Short introduction to cosmological perturbations from inflation BICEP2 and its implications for HEP and cosmology

3 The Universe is homogeneous and isotropic on sufficiently large scales, but has structure

4 The Universe has structure in the Cosmic Microwave Background

5 CMB 1964

6 Hydrogen Recombination & Last Scattering Surface Matter is ionized at temperatures higher than the hydrogen ionization energy of 13.6 ev n e n p = m et n H 2 3/2 e E ion/t The Universe becomes transparent to photons when ( e n e ) 1 t, e = 8 2 /3m 2 e, T LS 0.26 ev

7 CMB anisotropy T T (x 0, 0, n) = X`m a`m (x 0 )Y`m (n) D T T (n) ha`m a`0m 0 i = ``0 mm 0 C` T E T (n0 ) = X` (2` + 1) 4 C`P`(n n 0 )

8 CMB anisotropy Courtesy of M. Halpern

9 Where is this structure coming from?

10 Inflation

11 The Inflationary Cosmology Ḣ H 2 a(t) e Ht

12 Inflation makes locally the Universe flat a(t) e Ht

13 From Quantum Fluctuations to the Large Scale Structure

14 Particle production in an expanding Universe

15 All massless scalar fields are quantum-mechanically excited during Inflation (x, ) = 0( )+ (x, ), u k ( ) = a( ) k( ), d = dt a u k + k 2 a a u k = 0 Oscillator with time-dependent frequency

16 Any light scalar field is quantum mechanically excited during inflation with a scale-invariant power spectrum P = k3 2 2 k 2 = H 2 2 k ah n 1 n ' 1+O(10 2 )

17 The perturbations have a scale invariant spectrum because of scale invariance ds 2 = 1 H 2 2 (d 2 d~x 2 ) The metric is invariant under! and ~x! ~x

18 Ḣ H 2 In the high-energy physics language, the approximate time-translational invariance is associated to a pseudo-goldstone boson representing fluctuations in the clock a a H t H

19 Standard single-field models P = 1 H 2 n = = 2 M Pl 1/2 Ḣ H 2, = 2 H k ah n 1

20 The Millenium Simulation Project:

21 Tensor perturbations ds 2 = dt 2 a 2 ( ij + h ij )dx i dx j v k = am Pl 2 h k v k + k 2 a a v k = 0 P T (k) ' 8 M 2 Pl H 2 2 k ah nt H 2 ' E 4 inf/m 2 Pl n T = 2

22 Measuring the energy scale of inflation implies detecting tensor modes from inflation H ' E2 inf M Pl

23 The CMB anisotropy is polarized (~n )= ~ r (~n ) (~n )= ~ r a(~n )

24 Tensor modes induce B-mode polarization

25 IF B-mode polarization comes from inflation THEN r = P T P = 16 = 8n T

26 Bicep2

27 Bicep2 r = [ ( + 1)C B /2 ] 1/ (E inf /10 16 GeV) µk

28 Systematics at high multipoles? Leakage between E- and B-modes in the spherical harmonic decomposition? Different frequency check?

29 Dust induced polarization

30 353 GHz Planck collaboration (2014) Galactic dust emission increases with frequency so one would expect more of an effect in the Planck map than in BICEP2, but the fact that polarized foreground emission is so strong at these frequencies does give one pause for thought.

31 M.J. Mortonson and U. Seljak, (May 2014)

32 A tale of Two Cities, Charles Dickens (1859) It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair...

33 Implication 1

34 E Bicep2 ' GeV Coincidence? Problem?

35 Implication 2

36 Who is the inflaton?

37 Universe of maximum theoretical bliss? W.H. Kinney et al., in preparation

38 Universe of maximum theoretical bliss? V ( )= 1 2 m2 2 : = = 1 2N n 1= 2 N ' 0.96, r = 8 N ' 0.16

39 Implication 3

40 Observation of tensor modes imply Planckian field excursions r P scalar /P tensor r =8 1 M Pl d dn 2 ) M Pl ' 1.1 r 1/2 0.2

41 Invalidity of EFT? X p 4+p L p M p Pl 1. What is wrong with Planckian excursions? Are they physical (observable)? Usually not, when they are (e.g. radius of extra dimension) problems arise 2. What happens when other d.o.f. get a mass larger than the Planckian scale? Are non-renormalizable operators suppressed because of black hole arguments? 3. Shift symmetry:! + c ) p (V/M Pl ) p

42 Implication 4 Extra-dimensions

43 Large extra-dimensional models where the fundamental gravity mass is small are highly disfavoured S g = M 2+n Z d 4+n xr 4+n = M 2 Pl M 2 Pl = R n M 2+n Z d 4 xr 4 M E Bicep2 TeV-scale gravity ruled out

44 Implication 5 SM Higgs

45 d dlnµ = h4 t + (t)/ (0) vs t =ln(µ/m t ) UV UV UV J. Elias-Miro, J.R. Espinosa, G.F. Giudice, G. Isidori, A.R. and A. Strumia (2012)

46 D. Buttazzo et al. (2014)

47 Quantum tunneling hh 2 i' H 2 2 P surv exp H 3 t/32 2 UV J.R. Espinosa, G.F. Giudice and A.R. (2007)

48 K. Enqvist and S. Nurmi (2014)

49 H Bicep2 ' GeV UV During inflation, quantum fluctuations drive the Higgs field towards the instability region The SM Higgs must be coupled to either the inflaton or to gravity to avoid this catastrophe L Rh 2 = 12H 2 h 2

50 Implication 6 SM Higgs Inflation

51 Jordan frame: L = L EH + L SM Einstein frame: L = L SM M 2 Pl 2 Z d 4 x p ḡ µ = 2 g µ, 2 =1+ h2 M 2 Pl Z g 2 Rh2 d 4 x p ḡ R (@ )2 4 h 4 ( ) 4 ( ) Zee (1978), Salopek, Bond and Bardeen (1979), F. Bezrukov et al. (2008+)

52 Higgs Inflation 10 3 M h >M c = apple h t(173.2gev) s GeV

53 1 F. Bezrukov and M. Shaposhnikov (2014)

54 Implication 7 SUSY

55 Flat directions are a generic property of supersymmetry = eu 1 = e d 2 = e d 3 V ( )= 1 2 m2 ( ) 2 µ dm2 dµ ' g 2 3M g2 1M 2 1 The flat direction is unbounded from below and destabilzed during inflation unless scalar masses are typically larger than gaugino masses

56 Conclusions BICEP2 results under scrutiny If true High energy scale of inflation, possibly supporting GUTs The high energy scale of inflation dangerous for the SM Higgs, needs extra coupling; same true for the MSSM flat directions Large extra-dimensions rule out Window to Planckian physics