Probing the cosmological variation of the fine-structure constant: Results based on VLT-UVES sample
Open accessAbstract
Development of fundamental physics relies on the constancy of various fundamental quantities such as the fine-structure constant. Detecting or constraining the possible time variations of these fundamental physical quantities is an important step toward a complete understanding of basic physics. High-quality absorption lines seen in the spectra of distant QSOs allow one to probe time variations of several of these quantities. Here we present the results from a detailed many-multiplet analysis, to detect the possible variation of the fine-structure constant, performed using high signal-to-noise ratio, (~70 per pixel), high spectral resolution ( 45 000) observations of 23 Mg ii systems detected toward 18 QSOs in the redshift range obtained using UVES at the VLT. We validate our procedure and define the selection criteria that will avoid possible systematics using a detailed analysis of a simulated data set. The spectra of Mg ii doublets and Fe ii multiplets are generated considering variations in α and specifications identical to that of our UVES spectra. We show that our Voigt profile fitting code recovers the variation in α very accurately when we use single component systems and multiple-component systems that are not heavily blended. Spurious detections are frequently seen when we use heavily blended systems or systems with very weak lines. Thus we avoided these system while analysing the UVES data. To make the analysis transparent and accessible to the community for critical scrutiny, all the steps involved in the analysis are presented in detail. The weighted mean value of the variation in obtained from our analysis over the redshift range is = . The median redshift of our sample is 1.55 and corresponds to a look-back time of 9.7 Gyr in the most favored cosmological model today. The 3σ upper limit on the time variation of α is . To our knowledge this is the strongest constraint from quasar absorption line studies to till date.
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In order to avoid as much systematics as possible, the team applied a series of selection criteria on the systems used: similar ionization potentials, avoiding atmospheric contamination, high enough column density, at least one unsaturated anchor line, rejecting strongly saturated systems with large velocity spread, and keeping systems with majority of components separated by more than the Doppler
“In order to avoid as much systematics as possible, they apply a series of selection criteria (Chand et al. 2004) on the systems used: (1) consider only lines with similar ionization potentials (Mg II, Fe II, Si II and Al II) as they are most likely to originate from similar regions in the cloud; (2) avoid absorption lines contaminated by atmospheric lines; (3) consider only systems with hight”
From Fundamental constants: from measurement to the universe, a window on gravitation and cosmology (2025) · cites this paper as Chand et al. 2004
Chand et al. (2004) and Srianand et al. (2004) analyzed observations of 23 systems satisfying these criteria in the direction of 18 QSO with S/N ranging between 50 and 80 per pixel.
“Chand et al. (2004) and Srianand et al. (2004) analyzed the observations of 23 systems satisfying these criteria in direction of 18 QSO with a S/N ranging between 50 and 80 per pixel a”
From Fundamental constants: from measurement to the universe, a window on gravitation and cosmology (2025) · cites this paper as Chand et al. 2004
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BackgroundInfluentialSelf-citationDoes the Fine‐Structure Constant Vary with Cosmological Epoch?
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“However, the analysis of data from 23 absorption systems taken by the Very Large Telescope (VLT) ultraviolet and visual Echelle spectrograph (UVES) yielded a null result ∆α α = (−0.06± 0.06)× 10−5, (20) for 0.4 < z < 2.3 (Chand et al., 2004; Srianand et al., 2004).”
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“…of smaller data sets obtained from the Very Large Telescope (VLT) in Chile by other groups did not confirm the variation of α (Quast et al. 2004; Chand et al. 2004; Levshakov et al. 2005, 2006), though in some cases these analysis and uncertainty estimates have been challenged (Murphy et al.…”
ResultSelf-citationRevision of VLT/UVES constraints on a varying fine-structure constant
Murphy, M. T., Webb, J. K., & Flambaum, V. V. (2008) · Monthly Notices of the Royal Astronomical Society · doi:10.1111/j.1365-2966.2007.12695.x · Cited by 104 · see citing works
A new constraint on the time dependence of the proton-to-electron mass ratio
Ivanchik, A., Petitjean, P., Varshalovich, D., Aracil, B., Srianand, R., Chand, H., Ledoux, C., & Boissé, P. (2005) · Astronomy and Astrophysics · doi:10.1051/0004-6361:20052648 · Cited by 99 · see citing works
“Using ∆α/α from Murphy et al. (2003) gives −9.5 ≤ R ≤ −0.2 , and ∆α/α from Chand et al. (2004) gives |R| > 1 (at the 2σ C.L.).”
InfluentialSelf-citationVariation of the fine-structure constant: very high resolution spectrum of QSO HE 0515-4414
Chand, H., Srianand, R., Petitjean, P., Aracil, B., Quast, R., & Reimers, D. (2006) · Astronomy and Astrophysics · doi:10.1051/0004-6361:20054584 · Cited by 98 · see citing works
“In the analysis of Chand et al (2004, 2005)∆α/α is not explicitly used as fitting parameter.”
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“When searching for variations of physical constants during the last ∼1010 yr, the most frequently studied parameter is the fine-structure constant α (Webb et al. 1999, 2001; Murphy et al. 2003, 2008b; Chand et al. 2004; Levshakov et al. 2006, 2007; Rosenband et al. 2008).”
BackgroundRevision of VLT/UVES constraints on a varying fine-structure constant
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“Our method, which is close to that used by Levshakov, et al 2006, contrasts with that of Murphy et al. (2001a; 2001b; 2003; 2004) and Chand et al. (2004) where the signal/noise was not high enough to detect the ∆αα signal in any single pair of lines; they did a statistical averaging over many…”
MethodMurphy, M. T., Webb, J. K., & Flambaum, V. V. (2007) · Physical Review Letters · doi:10.1103/physrevlett.99.239001 · Cited by 91 · see citing works
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“The weighted mean of the corrected values is α/α = (−0.17 ± 0.06) × 10−5; a 2.5σ ‘detection’ of variation in αem compared to the null result of α/α = (−0.06 ± 0.06) × 10−5 claimed by Chand et al. (2004).”
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Dent, T., Stern, S., & WETTERICH, C. (2007) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.76.063513 · Cited by 83 · see citing works
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“These are the systems at zabs = 0.45207 (D’Odorico 2007), zabs = 1.5864 (Chand et al. 2004), zabs = 1.6515 (Paper I) which are suitable for measuring the Mg isotope abundances, and a sub-DLA system at zabs = 2.1871 (Richter et al. 2005) exhibiting several sets of absorption lines of the same ion…”
InfluentialKerber, F., Nave, G., & Sansonetti, C. J. (2008) · The Astrophysical Journal Supplement Series · doi:10.1086/590111 · Cited by 80 · see citing works
“Findings based on observations of astrophysical sources are discrepant; Murphy et al. (2003, 2004) obtained a value of / ¼ ( 0:57 0:11) ; 10 5, whereas Chand et al. (2004, 2006) find no evidence of a change in .”
Limits on Variations in Fundamental Constants from 21-cm and Ultraviolet Quasar Absorption Lines
Tzanavaris, P., Webb, J. K., Murphy, M. T., Flambaum, V. V., & Curran, S. J. (2005) · Physical Review Letters · doi:10.1103/physrevlett.95.041301 · Cited by 81 · see citing works
Most precise single redshift bound to $\mathsf{\Delta\alpha/\alpha}$
Levshakov, S. A., Centurión, M., Molaro, P. P., D’Odorico, S., Reimers, D., Quast, R., & Pollmann, M. (2006) · Astronomy and Astrophysics · doi:10.1051/0004-6361:20053827 · Cited by 79 · see citing works
“For instance, individual ∆α/α values obtained by Chand et al. (2004) are known with the accuracy of a few ppm.”
Astronomical measurements and constraints on the variability of fundamental constants
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“These results have nevertheless been challenged by similar (and more recent) analyses carried out in Chand et al. (2004) and Srianand et al. (2004) which will be described in the following sections.”
BackgroundResultInfluentialLevshakov, S. A., Molaro, P. P., López, S., D’Odorico, S., Centurión, M., Bonifacio, P., Agafonova, I. I., & Reimers, D. (2007) · Astronomy and Astrophysics · doi:10.1051/0004-6361:20066064 · Cited by 78 · see citing works
Nucleosynthesis and the variation of fundamental couplings
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UVES radial velocity accuracy from asteroid observations
Molaro, P. P., Levshakov, S. A., Monai, S., Centurión, M., Bonifacio, P., D’Odorico, S., & Monaco, L. (2008) · Astronomy and Astrophysics · doi:10.1051/0004-6361:20078864 · Cited by 76 · see citing works
“On the other hand, no variability has been measured by a different group at the VLT with UVES adopting similar techniques (Quast et al. 2004; Chand et al. 2004; Levshakov et al. 2005, 2006; but see also Murphy et al. 2008; and Srianand et al. 2007).”
MethodEvans, T. M., Murphy, M. T., Whitmore, J. B., Misawa, T., Centurion, M., D'Odorico, S., Lopez, S., Martins, C. J. A. P., Molaro, P., Petitjean, P., et al. (2014) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stu1754 · Cited by 75 · see citing works
“This method has been widely used to measure ∆α/α on cosmological scales since its development (e.g. Chand et al. 2004; Quast et al. 2004; Levshakov et al. 2005, 2007; Molaro et al. 2008).”
MethodSelf-citationCosmic Star Formation, Reionization, and Constraints on Global Chemical Evolution
Daigne, F., Olive, K. A., Vangioni–Flam, E., Silk, J. I., & Audouze, J. (2004) · The Astrophysical Journal · doi:10.1086/425649 · Cited by 73 · see citing works
“The same model has also been used recently to explain (Ashenfelter et al. 2004a, 2004b) the apparent observations of variations in the fine-structure constant in the similar quasar absorption systems (Murphy et al. 2003; Chand et al. 2004).”
MethodBounds on the fine structure constantvariability from Fe ii absorption lines in QSO spectra
Molaro, P. P., Reimers, D., Agafonova, I. I., & Levshakov, S. A. (2008) · The European Physical Journal Special Topics · doi:10.1140/epjst/e2008-00818-4 · Cited by 73 · see citing works
Breaking of the equivalence principle in the electromagnetic sector and its cosmological signatures
Hees, A., Minazzoli, O., & Larena, J. (2014) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.90.124064 · Cited by 72 · see citing works
Matter Non-conservation in the Universe and Dynamical Dark EnergyPreprint
Harald Fritzsch, A., & Solà, J. (2016) · Cited by 72 · see citing works
Kotuš, S., Murphy, M. T., & Carswell, R. F. (2016) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stw2543 · Cited by 71 · see citing works
“Contrary to these studies, several other attempts to measure α from individual absorbers (Quast et al. 2004; Chand et al. 2006; Levshakov et al. 2005, 2006, 2007) or smaller samples of absorption systems (Srianand et al. 2004; Chand et al. 2004) reported ∆α/α consistent with zero.”
BackgroundResultInfluentialVLT/UVES constraints on the cosmological variability of the fine-structure constant
Levshakov, S. A., Centurión, M., Molaro, P. P., & D’Odorico, S. (2005) · Astronomy and Astrophysics · doi:10.1051/0004-6361:20041827 · Cited by 71 · see citing works
“On the other hand, at metallicities of Z ∼ (0.1−1)Z⊙, – typical for the QSO systems with low ions, – the isotope abundances may not differ considerably from terrestrial (Murphy, Webb & Flambaum 2003; Chand et al. 2004, hereafter CSPA).”
BackgroundInfluentialReconstructing the dark energy equation of state with varying couplings
Avelino, P. P., Martins, C. J. A. P., Nunes, N. J., & Olive, K. A. (2006) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.74.083508 · Cited by 69 · see citing works
WAVELENGTH CALIBRATION OF THE VLT-UVES SPECTROGRAPH
Whitmore, J. B., Murphy, M. T., & Griest, K. (2010) · The Astrophysical Journal · doi:10.1088/0004-637x/723/1/89 · Cited by 72 · see citing works
“…1.1)× 10 −6, which is the most robust claimed detection of ∆αα (Murphy et al. 2001a, 2001b, 2003, 2004), and second there are several claimed limits on ∆αα near ∆α α < 1 × 10 −6 (Chand et al. 2004; Srianand et al. 2004; Levshakov et al. 2006, 2007; Molaro et al. 2008a; cf. Murphy et al. 2008).”
BackgroundInfluentialA new constraint on the time dependence of the proton-to-electron mass ratio
Ivanchik, A. V., Petitjean, P., Varshalovich, D. A., Aracil, B., Srianand, R., Chand, H., Ledoux, C., & Boissé, P. (2005) · Springer Link (Chiba Institute of Technology) · doi:10.1051/0004-6361:20052648/pdf · Cited by 66 · see citing works
Self-citationChand, H., Petitjean, P., Srianand, R., & Aracil, B. (2005) · Astronomy & Astrophysics · doi:10.1051/0004-6361:20041186 · Cited by 65 · see citing works
“However our recent investigation (Srianand et al. 2004 and Chand et al. 2004) using very high quality UVES data and well defined selection criteria resulted instead in a null detection of ∆α/α (∆α/α = (−0.06 ± 0.06) × 10−5) over the redshift range 0.4 ≤ z ≤ 2.3.”
MethodInfluentialSelf-citationQuintessence models and the cosmological evolution of α
Lee, S., Olive, K. A., & Pospelov, M. (2004) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.70.083503 · Cited by 65 · see citing works
Measuring the stability of fundamental constants with a network of clocks
Barontini, G., Blackburn, L., Boyer, V., Butuc-Mayer, F., Xavier Calmet, A., López-Urrutia, J. R. C., Curtis, E. A., Darquié, B., Dunningham, J., Fitch, N. J., et al. (2022) · EPJ Quantum Technology · doi:10.1140/epjqt/s40507-022-00130-5 · Cited by 65 · see citing works
Matter non-conservation in the universe and dynamical dark energy
Fritzsch, H., & Solà, J. (2012) · Classical and Quantum Gravity · doi:10.1088/0264-9381/29/21/215002 · Cited by 59 · see citing works
An upper limit to the secular variation of the gravitational constant from white dwarf stars
García-Berro, E., Lorén-Aguilar, P., Torres, S., Althaus, L. G., & Isern, J. (2011) · Journal of Cosmology and Astroparticle Physics · doi:10.1088/1475-7516/2011/05/021 · Cited by 59 · see citing works
Searching for chameleon-like scalar fields with the ammonia method
Levshakov, S. A., Molaro, P. P., Lapinov, A. V., Reimers, D., Henkel, C., & Sakai, T. (2010) · Astronomy and Astrophysics · doi:10.1051/0004-6361/200913007 · Cited by 59 · see citing works
“On the other hand, Chand et al. (2004) using VLT/UVES spectra of bright QSOs analyzed 23 absorption systems, which are not in common with those studied by the Keck telescope, and failed to reproduce Murphy et al.’s result.”
BackgroundMethodInfluentialMurphy, M. T., Tzanavaris, P., Webb, J. K., & Lovis, C. (2007) · reroDoc Digital Library · Cited by 59 · see citing works
Srianand, R., Chand, H., Petitjean, P., & Aracil, B. (2007) · Physical Review Letters · doi:10.1103/physrevlett.99.239002 · Cited by 59 · see citing works
Self-citationPrecision spectroscopy of the 3s−3p fine-structure doublet in Mg+
Batteiger, V., Knünz, S., Herrmann, M. G., Saathoff, G., Schüssler, H. A., Bernhardt, B., Wilken, T., Holzwarth, R., Hänsch, T. W., & Udem, T. (2009) · Physical Review A · doi:10.1103/physreva.80.022503 · Cited by 58 · see citing works
An upper limit to the secular variation of the gravitational constant from white dwarf stars
García Berro, E., Lorén–Aguilar, P., Torres, S., Althaus, L. G., & Isern, J. (2011) · Americanae (AECID Library) · Cited by 57 · see citing works
Hees, A., Do, T., Roberts, B. M., Ghez, A. M., Nishiyama, S., Bentley, R. O., Gautam, A. K., Jia, S., Kara, T., Lu, J. R., et al. (2020) · Physical Review Letters · doi:10.1103/physrevlett.124.081101 · Cited by 55 · see citing works
Scalar-tensor theories with pseudoscalar couplings
Flambaum, V. V., Lambert, S., & Pospelov, M. (2009) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.80.105021 · Cited by 55 · see citing works
General dynamics of varying-alpha universes
Barrow, J. D., & Graham, A. A. H. (2013) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.88.103513 · Cited by 54 · see citing works
Murphy, M. T., Molaro, P. P., Leite, A. C. O., Cupani, G., Cristiani, S., D’Odorico, V., Génova-Santos, R., Martins, C. J. A. P., Milaković, D., Nunes, N. J., et al. (2021) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202142257 · Cited by 54 · see citing works
Running vacuum in the Universe and the time variation of the fundamental constants of Nature
Fritzsch, H., Solà, J., & Nunes, R. C. (2017) · The European Physical Journal C · doi:10.1140/epjc/s10052-017-4714-z · Cited by 53 · see citing works
Constraining the variation of fundamental constants at z ∼ 1.3 using 21-cm absorbers
Rahmani, H., Srianand, R., Gupta, N., Petitjean, P., Noterdaeme, P., & Vásquez, D. A. (2012) · Monthly Notices of the Royal Astronomical Society · doi:10.1111/j.1365-2966.2012.21503.x · Cited by 52 · see citing works
Self-citationCosmological constraints on a dynamical electron mass
Barrow, J. D., & Magueijo, J. (2005) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.72.043521 · Cited by 51 · see citing works
Tzanavaris, P., Murphy, M. T., Webb, J. K., Flambaum, V. V., & Curran, S. J. (2006) · Monthly Notices of the Royal Astronomical Society · doi:10.1111/j.1365-2966.2006.11178.x · Cited by 51 · see citing works
“Using the claimed null-result on ∆α/α of Chand et al. (2004) yields ∆µ/µ = (0.75 ± 1.0) × 10−5.”
InfluentialBarrow, J. D. (2005) · Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences · doi:10.1098/rsta.2005.1634 · Cited by 49 · see citing works
Songaila, A., & Cowie, L. L. (2014) · The Astrophysical Journal · doi:10.1088/0004-637x/793/2/103 · Cited by 48 · see citing works
“The early results have been criticized by Murphy et al. (2008a, 2008b) who claim that their quoted significance is too high though not, in the case of the Chand et al. (2004, 2006) result, consistent with evidence for varying α (Srianand et al. 2007; Murphy et al. 2008a).”
MethodResultNonuniversal scalar-tensor theories and big bang nucleosynthesis
Coc, A., Olive, K. A., Uzan, J., & Vangioni–Flam, E. (2009) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.79.103512 · Cited by 48 · see citing works
Cosmological bounds on spatial variations of physical constants
Barrow, J. D. (2005) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.71.083520 · Cited by 46 · see citing works
Schmidt, T. M., Molaro, P. P., Murphy, M. T., Lovis, C., Cupani, G., Cristiani, S., Pepe, F. A., Rebolo, R., Santos, N. C., Abreu, M., et al. (2020) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202039345 · Cited by 46 · see citing works
Effects of the variation of fundamental constants on Population III stellar evolution
Ekström, S., Coc, A., Descouvemont, P., Meynet, G., Olive, K., Uzan, J., & Vangioni, E. (2010) · Astronomy and Astrophysics · doi:10.1051/0004-6361/200913684 · Cited by 39 · see citing works
“…values found in the claimed detections (Webb et al. 2001; Murphy et al. 2003, 2007) or a factor of 10 weaker than the limits from the non-detection (Chand et al. 2004; Srianand et al. 2004; Quast et al. 2004; Srianand et al. 2007) of a variation of αem from quasar absorption systems at redshifts z…”
BackgroundMethodInfluentialRunning vacuum in the Universe and the time variation of the fundamental constants of Nature
Harald Fritzsch, A., Solà, J., & Nunes, R. C. (2017) · Dipòsit Digital de la Universitat de Barcelona (Universitat de Barcelona) · Cited by 45 · see citing works
The density structure around quasars from optical depth statistics★
Rollinde, E., Srianand, R., Theuns, T., Petitjean, P., & Chand, H. (2005) · Monthly Notices of the Royal Astronomical Society · doi:10.1111/j.1365-2966.2005.08931.x · Cited by 45 · see citing works
“Details of the data reduction can be found in Chand et al. (2004) and Aracil et al. (2004).”
BackgroundSelf-citationOlive, K. A., Peloso, M., & Uzan, J.-P. (2011) · Physical Review D · doi:10.1103/physrevd.83.043509 · Cited by 44 · see citing works
Pradhan, A., Saha, B., & Rikhvitsky, V. (2014) · Indian Journal of Physics · doi:10.1007/s12648-014-0612-5 · Cited by 44 · see citing works
On variations in the fine-structure constant and stellar pollution of quasar absorption systems
Fenner, Y., Murphy, M. T., & Gibson, B. K. (2005) · Monthly Notices of the Royal Astronomical Society · doi:10.1111/j.1365-2966.2005.08781.x · Cited by 41 · see citing works
THE VARIATION OF THE GRAVITATIONAL CONSTANT INFERRED FROM THE HUBBLE DIAGRAM OF TYPE Ia SUPERNOVAE
García-Berro, E., Kubyshin, Y., Lorén-Aguilar, P., & Isern, J. (2005) · International Journal of Modern Physics D · doi:10.1142/s0218271806008772 · Cited by 32 · see citing works
Comments on “Note on varying speed of light theories”
Magueijo, J., & Moffat, J. W. (2007) · General Relativity and Gravitation · doi:10.1007/s10714-007-0568-2 · Cited by 41 · see citing works
Constraints on Dirac-Born-Infeld type dark energy models from varying alpha
Garousi, M. R., Sami, M., & Tsujikawa, S. (2004) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.71.083005 · Cited by 39 · see citing works
Dzuba, V. A., & Flambaum, V. V. (2008) · Physical Review A · doi:10.1103/physreva.77.012514 · Cited by 40 · see citing works
Aldenius, M., Johansson, S., & Murphy, M. T. (2006) · Monthly Notices of the Royal Astronomical Society · doi:10.1111/j.1365-2966.2006.10491.x · Cited by 40 · see citing works
“…have proven robust to many astrophysical and instrumental systematic errors (Murphy et al. 2001b, 2003), more recent studies of much smaller samples of VLT/UVES spectra suggest null results (Chand et al. 2004; Srianand et al. 2004; Quast et al. 2004; Levshakov et al. 2005; Chand et al. 2006).”
ResultMurphy, M. T., Malec, A. L., & Prochaska, J. X. (2016) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stw1482 · Cited by 39 · see citing works
“Note that the result from the VLT spectrum of J0058+0041, shown in italics, fails our selection criteria (Section 3.1) and is not considered in our statistical analysis in Section 4.3.”
ResultInfluentialSongaila, A., & Cowie, L. L. (2016) · Cited by 39 · see citing works
Schmidt, T. M., Molaro, P. P., Murphy, M. T., Lovis, C., Cupani, G., Cristiani, S., Pepe, F. A., Rebolo, R., Santos, N. C., Abreu, M. A., et al. (2021) · BORIS (University Library Bern) · Cited by 37 · see citing works
Clusters of galaxies and variation of the fine structure constant
Galli, S. (2013) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.87.123516 · Cited by 35 · see citing works
Tzanavaris, P., Murphy, M. T., Webb, J. K., Flambaum, V. V., & Curran, S. J. (2006) · UNSWorks (UNSW Sydney) · Cited by 37 · see citing works
Aldenius, M., Johansson, S., & Murphy, M. T. (2024) · CERN Document Server (European Organization for Nuclear Research) · doi:10.25916/sut.26230787.v1 · Cited by 37 · see citing works
A high-resolution study of intergalactic O vi absorbers at z∼ 2.3
Muzahid, S., Srianand, R., Bergeron, J., & Petitjean, P. (2012) · Monthly Notices of the Royal Astronomical Society · doi:10.1111/j.1365-2966.2011.20324.x · Cited by 36 · see citing works
“The detailed description of data calibration is presented in Aracil et al. (2004) and Chand et al. (2004).”
BackgroundSelf-citationPrimack, J. R. (2005) · New Astronomy Reviews · doi:10.1016/j.newar.2005.01.039 · Cited by 36 · see citing works
Cosmological evolution of alpha driven by a general coupling with quintessence
Marra, V., & Rosati, F. (2005) · Journal of Cosmology and Astroparticle Physics · doi:10.1088/1475-7516/2005/05/011 · Cited by 35 · see citing works
Fundamental constants and cosmic vacuum: The micro and macro connection
Fritzsch, H., & Solà, J. (2015) · Modern Physics Letters A · doi:10.1142/s0217732315400349 · Cited by 34 · see citing works
Varying couplings in electroweak theory
Shaw, D. J., & Barrow, J. D. (2005) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.71.063525 · Cited by 34 · see citing works
Shaw, D. J., & Barrow, J. D. (2006) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.73.123505 · Cited by 34 · see citing works
Ashenfelter, T. P., Mathews, G. J., & Olive, K. A. (2004) · The Astrophysical Journal · doi:10.1086/423929 · Cited by 34 · see citing works
“Scatter is found in the N=H data as well as the data from which Murphy et al. (2003a) and Chand et al. (2004) infer a value for = for each individual absorber.”
BackgroundMethodResultInfluentialLinearized Bekenstein varying α models
Avelino, P. P., Martins, C. J. A. P., & Oliveira, J. C. R. E. (2004) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.70.083506 · Cited by 34 · see citing works
Varying-alpha cosmologies with potentials
Barrow, J. D., & Li, B. (2008) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.78.083536 · Cited by 33 · see citing works
Berengut, J. C., Dzuba, V. A., Flambaum, V. V., & Marchenko, M. V. (2004) · Physical Review A · doi:10.1103/physreva.70.064101 · Cited by 32 · see citing works
Chiba, T., Kobayashi, T., Yamaguchi, M., & Yokoyama, J. (2007) · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · doi:10.1103/physrevd.75.043516 · Cited by 32 · see citing works
Nakashima, M., Ichikawa, K., Nagata, R., & Yokoyama, J. (2010) · Journal of Cosmology and Astroparticle Physics · doi:10.1088/1475-7516/2010/01/030 · Cited by 34 · see citing works
Gyromagnetic factors and atomic clock constraints on the variation of fundamental constants
Luo, F., Olive, K. A., & Uzan, J.-P. (2011) · Physical Review D · doi:10.1103/physrevd.84.096004 · Cited by 31 · see citing works
- Authors
- Chand, H., Srianand, R., Petitjean, P., & Aracil, B.
- Affiliations
- Inter-University Centre for Astronomy and Astrophysics (IN)
- Centre National de la Recherche Scientifique (FR)
- Venue
- Astronomy & Astrophysics
- Publisher
- EDP Sciences
- Published
- 2004-03-26
- Volume
- 417
- Issue
- 3
- Pages
- 853-871
- ISSN
- 0004-6361 (ISSN-L)
- 1432-0746
- OpenAlex
- W2112768623
- Cited by
- 239
- References
- 27
- Citations by year
- 2026: 1 · 2025: 1 · 2024: 2 · 2023: 4 · 2022: 4 · 2021: 6 · 2020: 2 · 2019: 3 · 2018: 3 · 2017: 7 · 2016: 8 · 2015: 7 · 2014: 11 · 2013: 14 · 2012: 7
- FWCI
- 16.32
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Astronomy and Astrophysics (publishedVersion)
- arXiv (Cornell University) (submittedVersion)
- arXiv (Cornell University)
- Funders
- Council of Scientific and Industrial Research, India
- Indo-French Centre for the Promotion of Advanced Research
- European Southern Observatory (166.A-0106)
- Centre National de la Recherche Scientifique
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Cosmology and Gravitation Theories
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Stellar, planetary, and galactic studies
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Galaxies: Formation, Evolution, Phenomena
- Keywords
- fine-structure constant variation, variation of fundamental constants, quasar absorption lines, Mg II doublet, Voigt profile fitting, cosmological constraints
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