ISMS-ConferenceChampaign-Urbana, 19 June 2014

Wim UbachsVU University Amsterdam

VLT PDA-XUV

High-resolution molecular spectroscopy of H2

at 10% the age of the Universe;Testing the constancy of physical law

Ti:Sa

Varying Constants ?

Bekenstein-Barrow –Sandvik – Mageijo – Light scalar fields f

1) Coupling to cosmologyVariation on cosmologicaltime scales

“matter dominated”

“dark energy dominated”

z ≈ 1

d

l

ceFFA

c

jLS mat

220

24

Coupling constants are free parameters in Standard Model

2) Coupling to matterdensity -> “chameleons”Coupling to gravity

Jacob Bekenstein

The dimensionless proton-electron mass ratio

m is a good test ground

Coupling constants interdependent in GUT

eQCD m/~

)75(15267245.8361e

p

m

M

K

Calculate Measure Determine

Experimental approach: look at molecules

Spectroscopy is the most accurate branch of science

The shifting power is expressed via sensitivity coefficients Kμ

At least two lines with different sensitivities are necessary for constraining Δμ/μ.

+ Redshift z - or – a time interval

iabsi

i

i Kzz

1110

Empirical search for a change in =Mp/me

Compare H2 spectra in different epochs:

QSO12 Gyr ago

Labtoday

90-112 nm

~275-350 nm

Edwin Hubble

Accurately calculated

Lab: 4 x 10-8

QSO: (2-10) x 10-7

ii

i z10 absii

i zz 110

ln

ln

d

idiK

Lyman bandsB1S+

u - X1S+g

Werner bandsC1Pu - X1S+

g

94 nm 110 nm

Ki are different for each line; Ki are small !!

Km sensitivity coefficients in H2

1

pMem

vibE

1

pMem

rotE

ConstelecE

(Rigid rotor)

(Harmonic oscillator)

H2 laboratory wavelengthsThe 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)

H2 laboratory wavelengths

FT-IR+Vis

XUV2-photondeep-UV

EF 1Sg+

B 1Su+

X 1Sg+

/Dl l ~ (5 – 50) x 10-9

Salumbides et al. Phys. Rev. Lett. 101 (2008) 223001Bailly et al., Mol. Phys. 108 (2010) 827

Two-step excitation Two-photon laser Doppler-free

FTIR and FT-VIS

>160 lines measuredat ~ 5 x 10-8

Some lines at < 1 x 10-8

VLT – UVESParanal, Chili

Keck – HIRESHawaii, VS

J2123 -005 at zabs=2.05

Unique spectrum from Keck; Resolution 110000 ; seeing 0.3”

37 panels

3071 – 3421 Å

~100 Hydrogen lines

7 HD lines

Spectrum from VLT; R=54000; seeing 0.8”; better SNR

“ComprehensiveFitting method”

Status of cosmological m-variation

Keck and VLT analysesconsistent !!

Q1441+272at z=4.2

March 2013

General message: | / |Dm m < 10-5

And J1237+0647 at zabs = 2.68957

Both CO (A1P-X1S+) and H2 observed strongly

(work in progress; UVES-VLT 2014 and laboratory)

Dependence of /Dm m on gravitational field

Spectrum of GD-133 White DwarfCosmic Origins Spectrograph - HSTWD=(GM/Rc2)=104Earth

Dependence of /Dm m on gravitational field

/Dm m < 5 x 10-5

Also in analysis: GD 29-38 at = 2 x 104 earth

To be published soon

> 1000 H2 lines !

Some conclusion

For redshifts z ~ 2 – 3.5 (10-12 Gyrs): 510

Rate of change:11510

yrt

At f=104 fearth:5105

Thanks & Acknowledgement

Edcel Salumbides

Julija Bagdonaite

Michael Murphy

MingLi Niu

LexKaper

MarioDapra