ISMS-Conference Champaign-Urbana, 19 June 2014 Wim Ubachs VU University Amsterdam VLT PDA-XUV High-resolution molecular spectroscopy of H 2 at 10% the age of the Universe; Testing the constancy of physical law Ti:Sa

Varying Constants ? Bekenstein-Barrow –Sandvik – Mageijo – Light scalar fields  1) Coupling to cosmology Variation on cosmological time scales “matter dominated” “dark energy dominated” z ≈ 1 Coupling constants are free parameters in Standard Model 2) Coupling to matter density -> “chameleons” Coupling to gravity Jacob Bekenstein

The dimensionless proton-electron mass ratio  is a good test ground Coupling constants interdependent in GUT

Calculate Measure Determine Experimental approach: look at molecules Spectroscopy is the most accurate branch of science The shifting power is expressed via sensitivity coefficients K μ At least two lines with different sensitivities are necessary for constraining Δμ/μ. + Redshift z - or – a time interval

Empirical search for a change in  =M p /m e Compare H 2 spectra in different epochs: QSO 12 Gyr ago Lab today nm ~ nm Edwin Hubble Accurately calculated Lab: 4 x QSO: (2-10) x 10 -7

Lyman bands B 1  + u - X 1  + g Werner bands C 1  u - X 1  + g 94 nm 110 nm K i are different for each line; K i are small !! K  sensitivity coefficients in H 2 (Rigid rotor) (Harmonic oscillator)

H 2 laboratory wavelengths The Amsterdam “XUV-laser” XUV-laser excitation P(3) C-X (1,0) R(0) B-X (9,0) line Ubachs, Phys. Rev. Lett. (2004) Reinhold et al, Phys. Rev. Lett. (2006) Salumbides et al, Phys. Rev. Lett. (2009) For HD Ivanov et al., Phys. Rev. Lett. (2008)

H 2 laboratory wavelengths FT-IR+Vis XUV 2-photon deep-UV EF 1  g + B 1  u + X 1  g +   ~ (5 – 50) x Salumbides et al. Phys. Rev. Lett. 101 (2008) Bailly et al., Mol. Phys. 108 (2010) 827 Two-step excitation Two-photon laser Doppler-free FTIR and FT-VIS

>160 lines measured at ~ 5 x Some lines at < 1 x 10 -8

VLT – UVES Paranal, Chili Keck – HIRES Hawaii, VS

J at z abs =2.05 Unique spectrum from Keck; Resolution ; seeing 0.3” 37 panels 3071 – 3421 Å ~100 Hydrogen lines 7 HD lines Spectrum from VLT; R=54000; seeing 0.8”; better SNR “Comprehensive Fitting method”

Status of cosmological  -variation Keck and VLT analyses consistent !! Q at z=4.2 March 2013 General message  < 10 -5

And J at z abs = Both CO (A 1  -X 1  + ) and H 2 observed strongly (work in progress; UVES-VLT 2014 and laboratory)

Dependence of  on gravitational field Spectrum of GD-133 White Dwarf Cosmic Origins Spectrograph - HST  WD =(GM/Rc 2 )=10 4  Earth

Dependence of  on gravitational field  < 5 x Also in analysis: GD at  = 2 x 10 4  earth To be published soon > 1000 H 2 lines !

Some conclusion For redshifts z ~ 2 – 3.5 (10-12 Gyrs): Rate of change: At  =10 4  earth :

Thanks & Acknowledgement Edcel Salumbides Julija Bagdonaite Michael Murphy MingLi Niu Lex Kaper Mario Dapra