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Trachenko K. Viscosity and diffusion in life processes and tuning of fundamental constants. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2023; 86:112601. [PMID: 37811635 DOI: 10.1088/1361-6633/acfd3e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 09/26/2023] [Indexed: 10/10/2023]
Abstract
Viewed as one of the grandest questions in modern science, understanding fundamental physical constants has been discussed in high-energy particle physics, astronomy and cosmology. Here, I review how condensed matter and liquid physics gives new insights into fundamental constants and their tuning. This is based on two observations: first, cellular life and the existence of observers depend on viscosity and diffusion. Second, the lower bound on viscosity and upper bound on diffusion are set by fundamental constants, and I briefly review this result and related recent developments in liquid physics. I will subsequently show that bounds on viscosity, diffusion and the newly introduced fundamental velocity gradient in a biochemical machine can all be varied while keeping the fine-structure constant and the proton-to-electron mass ratio intact. This implies that it is possible to produce heavy elements in stars but have a viscous planet where all liquids have very high viscosity (for example that of tar or higher) and where life may not exist. Knowing the range of bio-friendly viscosity and diffusion, we will be able to calculate the range of fundamental constants which favour cellular life and observers and compare this tuning with that discussed in high-energy physics previously. This invites an inter-disciplinary research between condensed matter physics and life sciences, and I formulate several questions that life science can address. I finish with a conjecture of multiple tuning and an evolutionary mechanism.
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Affiliation(s)
- K Trachenko
- School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
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Bahamonde S, Dialektopoulos KF, Escamilla-Rivera C, Farrugia G, Gakis V, Hendry M, Hohmann M, Levi Said J, Mifsud J, Di Valentino E. Teleparallel gravity: from theory to cosmology. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2023; 86:026901. [PMID: 36279849 DOI: 10.1088/1361-6633/ac9cef] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Teleparallel gravity (TG) has significantly increased in popularity in recent decades, bringing attention to Einstein's other theory of gravity. In this Review, we give a comprehensive introduction to how teleparallel geometry is developed as a gauge theory of translations together with all the other properties of gauge field theory. This relates the geometry to the broader metric-affine approach to forming gravitational theories where we describe a systematic way of constructing consistent teleparallel theories that respect certain physical conditions such as local Lorentz invariance. We first use TG to formulate a teleparallel equivalent of general relativity (GR) which is dynamically equivalent to GR but which may have different behaviors for other scenarios, such as quantum gravity. After setting this foundation, we describe the plethora of modified teleparallel theories of gravity that have been proposed in the literature. We attempt to connect them together into general classes of covariant gravitational theories. Of particular interest, we highlight the recent proposal of a teleparallel analogue of Horndeski gravity which offers the possibility of reviving all of the regular Horndeski contributions. In the second part of the Review, we first survey works in teleparallel astrophysics literature where we focus on the open questions in this regime of physics. We then discuss the cosmological consequences for the various formulations of TG. We do this at background level by exploring works using various approaches ranging from dynamical systems to Noether symmetries, and more. Naturally, we then discuss perturbation theory, firstly by giving a concise approach in which this can be applied in TG theories and then apply it to a number of important theories in the literature. Finally, we examine works in observational and precision cosmology across the plethora of proposal theories. This is done using some of the latest observations and is used to tackle cosmological tensions which may be alleviated in teleparallel cosmology. We also introduce a number of recent works in the application of machine learning to gravity, we do this through deep learning and Gaussian processes, together with discussions about other approaches in the literature.
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Affiliation(s)
- Sebastian Bahamonde
- Laboratory of Theoretical Physics, Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411 Tartu, Estonia
- Department of Physics, Tokyo Institute of Technology, 1-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Konstantinos F Dialektopoulos
- Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou 225009, People's Republic of China
- Laboratory of Physics, Faculty of Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- Department of Physics, Nazarbayev University, 53 Kabanbay Batyr Avenue, 010000 Astana, Kazakhstan
| | - Celia Escamilla-Rivera
- Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C.U., A.P. 70-543, México D.F. 04510, Mexico
| | - Gabriel Farrugia
- Institute of Space Sciences and Astronomy, University of Malta, Msida, Malta
- Department of Physics, University of Malta, Msida, Malta
| | - Viktor Gakis
- Institute of Space Sciences and Astronomy, University of Malta, Msida, Malta
- Department of Physics, University of Malta, Msida, Malta
- Department of Physics, National Technical University of Athens, Zografou Campus GR 157 73, Athens, Greece
| | - Martin Hendry
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Manuel Hohmann
- Laboratory of Theoretical Physics, Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411 Tartu, Estonia
| | - Jackson Levi Said
- Institute of Space Sciences and Astronomy, University of Malta, Msida, Malta
- Department of Physics, University of Malta, Msida, Malta
| | - Jurgen Mifsud
- Institute of Space Sciences and Astronomy, University of Malta, Msida, Malta
- Department of Physics, University of Malta, Msida, Malta
| | - Eleonora Di Valentino
- Institute for Particle Physics Phenomenology, Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
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3
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Davoudiasl H, Gehrlein J, Szafron R. Is the θ[over ¯] Parameter of QCD Constant? PHYSICAL REVIEW LETTERS 2022; 129:161802. [PMID: 36306742 DOI: 10.1103/physrevlett.129.161802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/22/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Testing the cosmological variation of fundamental constants of nature can provide valuable insights into new physics scenarios. While many such constraints have been derived for standard model coupling constants and masses, the θ[over ¯] parameter of QCD has not been as extensively examined. In this Letter, we discuss potentially promising paths to investigate the time dependence of the θ[over ¯] parameter. While laboratory searches for CP-violating signals of θ[over ¯] yield the most robust bounds on today's value of θ[over ¯], we show that CP-conserving effects provide constraints on the variation of θ[over ¯] over cosmological timescales. We find no evidence for a variation of θ[over ¯] that could have implied an "iron-deficient" Universe at higher redshifts. By converting recent atomic clock constraints on a variation of constants, we infer d(θ[over ¯]^{2})/dt≤6×10^{-15} yr^{-1}, at 1σ. Finally, we also sketch an axion model that results in a varying θ[over ¯] and could lead to excess diffuse gamma ray background, from decays of axions produced in high redshift supernova explosions.
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Affiliation(s)
- Hooman Davoudiasl
- Physics Department, Brookhaven National Laboratory, High Energy Theory Group, Upton, New York 11973, USA
| | - Julia Gehrlein
- Physics Department, Brookhaven National Laboratory, High Energy Theory Group, Upton, New York 11973, USA
| | - Robert Szafron
- Physics Department, Brookhaven National Laboratory, High Energy Theory Group, Upton, New York 11973, USA
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Lange R, Huntemann N, Rahm JM, Sanner C, Shao H, Lipphardt B, Tamm C, Weyers S, Peik E. Improved Limits for Violations of Local Position Invariance from Atomic Clock Comparisons. PHYSICAL REVIEW LETTERS 2021; 126:011102. [PMID: 33480794 DOI: 10.1103/physrevlett.126.011102] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/23/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
We compare two optical clocks based on the ^{2}S_{1/2}(F=0)→^{2}D_{3/2}(F=2) electric quadrupole (E2) and the ^{2}S_{1/2}(F=0)→^{2}F_{7/2}(F=3) electric octupole (E3) transition of ^{171}Yb^{+} and measure the frequency ratio ν_{E3}/ν_{E2}=0.932829404530965376(32), improving upon previous measurements by an order of magnitude. Using two caesium fountain clocks, we find ν_{E3}=642121496772645.10(8) Hz, the most accurate determination of an optical transition frequency to date. Repeated measurements of both quantities over several years are analyzed for potential violations of local position invariance. We improve by factors of about 20 and 2 the limits for fractional temporal variations of the fine structure constant α to 1.0(1.1)×10^{-18}/yr and of the proton-to-electron mass ratio μ to -8(36)×10^{-18}/yr. Using the annual variation of the Sun's gravitational potential at Earth Φ, we improve limits for a potential coupling of both constants to gravity, (c^{2}/α)(dα/dΦ)=14(11)×10^{-9} and (c^{2}/μ)(dμ/dΦ)=7(45)×10^{-8}.
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Affiliation(s)
- R Lange
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - N Huntemann
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - J M Rahm
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - C Sanner
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - H Shao
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - B Lipphardt
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - Chr Tamm
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - S Weyers
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - E Peik
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
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Hansmann AK, Berger R. Variation of the Fine-Structure Constant in Model Systems for Singlet Fission. J Phys Chem A 2020; 124:6682-6687. [DOI: 10.1021/acs.jpca.0c04685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna-Katharina Hansmann
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Robert Berger
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
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Wilczynska MR, Webb JK, Bainbridge M, Barrow JD, Bosman SEI, Carswell RF, Dąbrowski MP, Dumont V, Lee CC, Leite AC, Leszczyńska K, Liske J, Marosek K, Martins CJAP, Milaković D, Molaro P, Pasquini L. Four direct measurements of the fine-structure constant 13 billion years ago. SCIENCE ADVANCES 2020; 6:6/17/eaay9672. [PMID: 32917582 PMCID: PMC7182409 DOI: 10.1126/sciadv.aay9672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/15/2020] [Indexed: 06/11/2023]
Abstract
Observations of the redshift z = 7.085 quasar J1120+0641 are used to search for variations of the fine structure constant, α, over the redshift range 5.5 to 7.1. Observations at z = 7.1 probe the physics of the universe at only 0.8 billion years old. These are the most distant direct measurements of α to date and the first measurements using a near-IR spectrograph. A new AI analysis method is employed. Four measurements from the x-shooter spectrograph on the Very Large Telescope (VLT) constrain changes in a relative to the terrestrial value (α0). The weighted mean electromagnetic force in this location in the universe deviates from the terrestrial value by Δα/α = (α z - α0)/α0 = (-2.18 ± 7.27) × 10-5, consistent with no temporal change. Combining these measurements with existing data, we find a spatial variation is preferred over a no-variation model at the 3.9σ level.
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Affiliation(s)
| | - John K Webb
- University of New South Wales Sydney, Sydney, NSW 2052, Australia.
| | - Matthew Bainbridge
- College of Science and Engineering, University of Leicester, University Road, Leicester LE17RH, UK
| | - John D Barrow
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Cambridge CB3 0WA, UK
| | - Sarah E I Bosman
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | | | - Mariusz P Dąbrowski
- Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451 Szczecin, Poland
| | - Vincent Dumont
- Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Chung-Chi Lee
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Cambridge CB3 0WA, UK
| | - Ana Catarina Leite
- Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
- Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
- Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4150-007 Porto, Portugal
| | - Katarzyna Leszczyńska
- Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451 Szczecin, Poland
| | - Jochen Liske
- Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, D-21029 Hamburg, Germany
| | - Konrad Marosek
- Maritime University, Wały Chrobrego 1-2, 70-500 Szczecin, Poland
| | - Carlos J A P Martins
- Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
- Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
| | - Dinko Milaković
- European Southern Observatory, 85748 Garching bei München, Germany
- Ludwig-Maximilians-Universität, 80799 Munich, Germany
| | - Paolo Molaro
- National Institute for Astrophysics, Astronomical Observatory of Trieste, Via G.B. Tiepolo 11, I34134, Italy
| | - Luca Pasquini
- European Southern Observatory, 85748 Garching bei München, Germany
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Probing Time-Dependent Fundamental Constants with Nucleosynthesis in Population III Stars. Symmetry (Basel) 2020. [DOI: 10.3390/sym12030404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Variations of fundamental physical constants have been sought for many years using various astronomical objects because their discovery can be key to developing beyond-standard physics. In particular, nuclear reaction rates are sensitive to fundamental constants, so nucleosynthetic processes can be used as a probe. We calculate the evolution and nucleosynthesis of massive Population III stars with the time-dependent nucleon–nucleon interaction δ NN , which may have left traces in elemental abundances in extremely metal-poor stars. The results are compared with the abundances in the most iron-poor star that has ever been discovered, namely, SMSS J031300.36-670839.3. It is found that calcium production in Population III stars is very sensitive to variations of the triple- α reaction rate and hence δ NN . We conclude that variations of the nucleon–nucleon interaction are constrained as − 0.002 < δ NN < 0.002 at the redshift z ∼ 20 , assuming that calcium in SMSS J031300.36-670839.3 originates from hydrogen burning in a massive Population III star.
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Syme AM, Mousley A, Cunningham M, McKemmish LK. Diatomic Rovibronic Transitions as Potential Probes for Proton-to-Electron Mass Ratio Across Cosmological Time. Aust J Chem 2020. [DOI: 10.1071/ch19448] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Astrophysical molecular spectroscopy is an important method of searching for new physics through probing the variation of the proton-to-electron mass ratio, μ, with existing constraints limiting variation to a fractional change of less than 10−17per year. To improve on this constraint and therefore provide better guidance to theories of new physics, new molecular probes will be useful. These probes must have spectral transitions that are observable astrophysically and have different sensitivities to variation in the proton-to-electron mass ratio. Here, we concisely detail how the set of potential molecular probes and promising sensitive transitions is constrained based on how the frequency and intensity of these transitions align with available telescopes. Our detailed investigation focuses on rovibronic transitions in astrophysical diatomic molecules, using the spectroscopic models of 11 diatomics to identify sensitive transitions and probe how they generally arise in real complex molecules with many electronic states and fine structure. While none of the 11 diatomics investigated have sensitive transitions likely to be astrophysically observable, we have found that at high temperatures (1000K) five of these diatomics have a significant number of low intensity sensitive transitions arising from an accidental near-degeneracy between vibrational levels in the ground and excited electronic states. This insight enables screening of all astrophysical diatomics as potential probes of proton-to-electron mass variation, with CN, CP, SiN and SiC being the most promising candidates for further investigation for sensitivity in rovibronic transitions.
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Martins C, Vacher L. Astrophysical and local constraints on string theory: Runaway dilaton models. Int J Clin Exp Med 2019. [DOI: 10.1103/physrevd.100.123514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
We have developed a cosmological model by allowing the speed of light c, gravitational constant G and cosmological constant Λ in the Einstein filed equation to vary in time, and solved them for Robertson-Walker metric. Assuming the universe is flat and matter dominant at present, we obtain a simple model that can fit the supernovae 1a data with a single parameter almost as well as the standard ΛCDM model with two parameters, and which has the predictive capability superior to the latter. The model, together with the null results for the variation of G from the analysis of lunar laser ranging data determines that at the current time G and c both increase as dG/dt = 5.4GH0 and dc/dt = 1.8cH0 with H0 as the Hubble constant, and Λ decreases as dΛ/dt = −1.2ΛH0. This variation of G and c is all what is needed to account for the Pioneer anomaly, the anomalous secular increase of the moon eccentricity, and the anomalous secular increase of the astronomical unit. We also show that the Planck’s constant ħ increases as dħ/dt = 1.8ħH0 and the ratio D of any Hubble unit to the corresponding Planck unit increases as dD/dt = 1.5DH0. We have shown that it is essential to consider the variation of all the physical constants that may be involved directly or indirectly in a measurement rather than only the one whose variation is of interest.
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McKnight Q, Bergeson SD, Peatross J, Ware MJ. 2.7 years of beta-decay-rate ratio measurements in a controlled environment. Appl Radiat Isot 2018; 142:113-119. [PMID: 30273759 DOI: 10.1016/j.apradiso.2018.09.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 11/19/2022]
Abstract
We report nearly continuous beta-decay-rate measurements of Na-22, Cl-36, Co-60, Sr-90, and Cs-137 over a period of 2.7 years using four Geiger-Müller tubes. We carefully control the ambient pressure and temperature for the detectors, sources, and electronics in order to minimize environmentally-dependent systematic drifts in the measurement chains. We show that the amplitudes of an annual oscillation in the decay rates are consistent with zero to within 0.004%.
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Affiliation(s)
- Q McKnight
- Department of Physics and Astronomy, Brigham Young University, Provo, UT 84602, United States
| | - S D Bergeson
- Department of Physics and Astronomy, Brigham Young University, Provo, UT 84602, United States.
| | - J Peatross
- Department of Physics and Astronomy, Brigham Young University, Provo, UT 84602, United States
| | - M J Ware
- Department of Physics and Astronomy, Brigham Young University, Provo, UT 84602, United States
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