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The SFB 676 has been funded by the DFG from 2006 to 2018. The project was completed with a special colloquium in June 2018. A book with the scientific results of the SFB 676 has been published in September 2018.

J. Haller and M. Grefe (eds.), “Particles, Strings and the Early Universe: The Structure of Matter and Space-Time,” Hamburg (2018), DOI: 10.3204/PUBDB-2018-00782.

Many research directions developed within the SFB 676 will be continued within the Cluster of Excellence "Quantum Universe" starting 1 January 2019.

C4 – Variations of Fundamental Constants

Project Leaders

Dieter Reimers (e-mail | group homepage)


Measuring the variability of fundamental constants offers one of the few tests for string theory. Among the various experimental approaches, astronomical methods enable us to constrain the variation of the fine-structure constant and the proton-to-electron mass ratio with cosmic epoch. We plan to study suitable quasar absorption line systems in the brightest QSOs from the Hamburg QSO surveys with the UVES spectrograph at the ESO VLT with the highest possible resolution and S/N. We furter intend to improve the accuracy of the calculation of the necessary atomic constants, in particular the isotopic shifts for FeII lines.

Former members

Robert Baade

Nils Prause

Martin Wendt


Get these publications as bibtex-file

"A rotating helical filament in the L1251 dark cloud"
Levshakov, S.A. and Reimers, D. and Henkel, C.
Astron. Astrophys. 586, A126 (2016)
doi: 10.1051/0004-6361/201527783
eprint: 1601.00291 [astro-ph.GA]

"Star-forming regions of the Aquila rift cloud complex. II. Turbulence in molecular cores probed by NH3 emission"
Levshakov, S.A. and Henkel, C. and Reimers, D. and Wang, M.
Astron. Astrophys. 567, A78 (2014)
doi: 10.1051/0004-6361/201423732
eprint: 1405.7492 [astro-ph.GA]

"Fundamental constants and high resolution spectroscopy"
Bonifacio, P. and others
Astron. Nachr. 335, 83 (2014)
doi: 10.1002/asna.201312005
eprint: 1310.6280 [astro-ph.CO]

"Limits on the spatial variations of the electron-to-proton mass ratio in the Galactic plane"
Levshakov, S.A. and Reimers, D. and Henkel, C. and Winkel, B. and Mignano, A. and Centurion, M. and Molaro, P.
Astron. Astrophys. 559, A91 (2013)
doi: 10.1051/0004-6361/201322535
eprint: 1310.1850 [astro-ph.GA]

"The UVES Large Program for Testing Fundamental Physics II: Constraints on a Change in µ Towards Quasar HE 0027-1836"
Rahmani, H. and others
Mon. Not. Roy. Astron. Soc. 435, 861-878 (2013)
doi: 10.1093/mnras/stt1356
eprint: 1307.5864 [astro-ph.CO]

"The precision of line position measurements of unresolved quasar absorption lines and its influence on the search for variations of fundamental constants"
Prause, Nils and Reimers, Dieter
Astron. Astrophys. 555, A88 (2013)
doi: 10.1051/0004-6361/201118373
eprint: 1305.6178 [astro-ph.CO]

"The UVES Large Program for Testing Fundamental Physics: I Bounds on a change in alpha towards quasar HE 2217-2818"
Molaro, P. and others
Astron. Astrophys. 555, A68 (2013)
doi: 10.1051/0004-6361/201321351
eprint: 1305.1884 [astro-ph.CO]

"Star-forming regions of the Aquila rift cloud complex. I. NH3 tracers of dense molecular cores"
Levshakov, S.A. and Henkel, C. and Reimers, D. and Wang, M. and Mao, R. and others
Astron. Astrophys. 553, 58 (2013)
doi: 10.1051/0004-6361/201220354
eprint: 1303.2052 [astro-ph.GA]

"An upper limit to the variation in the fundamental constants at redshift z = 5.2"
Levshakov, S.A. and Combes, F. and Boone, F. and Agafonova, I.I. and Reimers, D. and others
Astron. Astrophys. 540, L9 (2012)
doi: 10.1051/0004-6361/201219042
eprint: 1203.3649 [astro-ph.CO]

"Methanol as a tracer of fundamental constants"
Levshakov, S.A. and Kozlov, M.G. and Reimers, D.
Astrophys.J. 738, 26 (2011)
doi: 10.1088/0004-637X/738/1/26
eprint: 1106.1569 [astro-ph.CO]

"Sensitivity of the isotopologues of hydronium to variation of the electron-to-proton mass ratio"
Kozlov, M.G. and Porsev, S.G. and Reimers, D.
Phys.Rev. A83, 052123 (2011)
doi: 10.1103/PhysRevA.83.052123
eprint: 1103.4739 [physics.atom-ph]

"Searching for spatial variations of α²/μ in the Milky Way"
Levshakov, S.A. and Molaro, P. and Reimers, D.
Astron. Astrophys. 516, 113 (2010)
doi: 10.1051/0004-6361/200913558
eprint: 1004.0783 [astro-ph.CO]

"Transition frequency shifts with fine-structure constant variation for Fe I and isotope-shift calculations in Fe I and Fe II"
Porsev, S. G. and Kozlov, M. G. and Reimers, D.
Phys. Rev. A 79, 032519 (2009)
doi: 10.1103/PhysRevA.79.032519
eprint: 0903.1679 [astro-ph.CO]

"Coefficients for sensitivity of fine-structure transitions in carbonlike ions to α variation"
Kozlov, M. G. and Tupitsyn, I. I. and Reimers, D.
Phys. Rev. A 79, 022117 (2009)
doi: 10.1103/PhysRevA.79.022117
eprint: 0812.3210 [physics.atom-ph]

"Variability of the proton-to-electron mass ratio on cosmological scales"
Wendt, Martin and Reimers, Dieter
Eur. Phys. J. ST 163, 197-206 (2008)
doi: 10.1140/epjst/e2008-00820-x
eprint: 0802.1160 [astro-ph]

"Mid- and far-infrared fine-structure line sensitivities to hypothetical variability of the fine-structure constant"
Kozlov, M. G. and Porsev, S. G. and Levshakov, S. A. and Reimers, D. and Molaro, P.
Phys. Rev. A77, 032119 (2008)
doi: 10.1103/PhysRevA.77.032119
eprint: 0802.0269 [astro-ph]

"Bounds on the fine structure constant variability from FeII absorption lines in QSO spectra"
Molaro, Paolo and Reimers, Dieter and Agafonova, Irina I. and Levshakov, Sergei A.
Eur. Phys. J. ST 163, 173-189 (2008)
doi: 10.1140/epjst/e2008-00818-4
eprint: 0712.4380 [astro-ph]

"A new approach for testing variations of fundamental constants over cosmic epochs using FIR fine-structure lines"
Levshakov, S. A. and Reimers, D. and Kozlov, M. G. and Porsev, S. G. and Molaro, P.
Astron. Astrophys. 479, 719 (2008)
doi: 10.1051/0004-6361:20079116
eprint: 0712.2890 [astro-ph]

"HE 0515-4414: An unusual sub-damped Ly α system revisited"
Quast, R. and Reimers, D. and Baade, R.
Astron. Astrophys. 477, 443 (2008)
doi: 10.1051/0004-6361:20054773
eprint: 0710.3560 [astro-ph]

"Sensitivity of microwave molecular transitions and atomic FIR transitions from quasar spectra to variation of fundamental constants"
Kozlov, M. and Flambaum, V. and Levshakov, S. and Reimers, D. and Porsev, S. and Molaro, P.
Problems of Practical Cosmology, Volume 2 (2008)
[ link ]

"A new measure of Δα/α at redshift z = 1.84 from very high resolution spectra of Q1101-264"
Levshakov, S. A. and Molaro, P. and Lopez, S. and D'Odorico, S. and Centurion, M. and Bonifacio, P. and Agafonova, I. I. and Reimers, D.
Astron. Astrophys. 466, 1077-1082 (2007)
doi: 10.1051/0004-6361:20066064
eprint: astro-ph/0703042 [ASTRO-PH]

"High-Precision Measurements of Δα/α from QSO Absorption Spectra"
Levshakov, Sergei A. and Molaro, Paolo and Lopez, Sebastian and D'Odorico, Sandro and Centurion, Miriam and Bonifacio, Piercarlo and Agafonova, Irina I. and Reimers, Dieter
Conference on Precision Spectroscopy in Astrophysics Aveiro, Portugal, September 11-15, 2006 (2006)
eprint: astro-ph/0611803 [astro-ph]


PhD thesis: "The influence of asymmetric line profiles on the reliability of the search for varying fundamental constants"
Nils Prause
Universität Hamburg (2014)
[ link ]

PhD thesis: "Probing cosmological variation of the proton-to-electron mass ratio by means of quasar absorption spectra"
Martin Wendt
Universität Hamburg (2010)
[ link ]

Impressum  | last modified 27 Jul 2018