Article
Astronomy & Astrophysics
Leo Vacher, Nils Schoneberg, J. D. F. Dias, C. J. A. P. Martins, Francisco Pimenta
Summary: One of the firm predictions of string theory is the existence of a massless scalar field, the dilaton, coupled to gravity, which violates the Einstein equivalence principle. The runaway dilaton proposed by Damour, Piazza, and Veneziano reconciles the existence of a massless dilaton with observations and predicts nonstandard and testable phenomena. This field can also serve as a natural candidate for dynamical dark energy. Despite previous constraints, we present the first comprehensive constraints on this model, incorporating high redshift data, and ruling out order unity couplings.
Article
Optics
Yevgeny Stadnik
Summary: Quasar absorption spectral data suggest the presence of a spatial gradient in the electromagnetic fine-structure constant alpha on cosmological scales. Accelerometer experiments can serve as sensitive probes of such gradients, with laboratory data indicating potential for improved sensitivity in the future.
Article
Materials Science, Multidisciplinary
Dingfeng Yang, Shuling Chen, Xuejun Quan, Yaoqiong Wang, Xiangnan Gong, Yuanyuan Li
Summary: This study investigated the electronic structure, temperature dependent elasticity, and thermodynamical properties of thermoelectric material NiSbS using the quasi-harmonic approximation. The results showed that NiSbS exhibits metallic behavior with a band characteristic similar to that of n-type heavily doped semiconductors. The temperature-dependent elastic constants decrease with increasing temperature and satisfy stability conditions. Thermodynamical calculations suggest that NiSbS has a weak expansion. These findings predict that NiSbS has good mechanical properties for thermoelectric device applications.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
R. Oswald, A. Nevsky, V. Vogt, S. Schiller, N. L. Figueroa, K. Zhang, O. Tretiak, D. Antypas, D. Budker, A. Banerjee, G. Perez
Summary: Scientists have conducted spectroscopic experiments to study the interactions between ultralight dark matter fields and standard model degrees of freedom. They have established experimental bounds on the coupling of these fields to quarks, gluons, and various fields, and identified a portion of the coupling space that may challenge the constraints from equivalence principle tests.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Bodo Lampe
Summary: The study in the framework of a new dark energy interpretation examines the cosmic time dependencies of parameters like G, alpha, PLANCK CONSTANT OVER TWO PI, and the Higgs vev in the Standard Model, revealing that many effects are invisible due to the time variation of rulers. A significant time dependence is claimed to be associated with dark energy measurements, with smaller ones in connection with the Standard Model.
FORTSCHRITTE DER PHYSIK-PROGRESS OF PHYSICS
(2021)
Article
Physics, Applied
Xiangen Liu, Alexey M. Lomonosov, Zhonghua Shen
Summary: Dispersion of surface acoustic waves caused by dynamic surface heating-cooling cycle is used to evaluate thermal properties. The dispersion curves are measured at multiple time instants to evaluate thermal diffusivity, temperature dependence of shear modulus, and temperature magnitude. The inverse problem is solved by fitting experimental dispersion curves with theoretical ones using differential evolution techniques.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Multidisciplinary
Emilio Fiordilino
Summary: Two protocols are presented in this study to set an upper limit on claimed variations in atomic position, both involving the use of delayed laser pulses to drive the atoms. The distinct positions of the laboratory due to Earth’s motion affect the dynamics of the atoms. These protocols improve the reported upper limit of Delta/ and induce chaotic evolution in the atom, showcasing an example of parametric chaos.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Chemistry, Physical
Michael Schobitz, Ondrej Novotny, Beatrix Trapp, Sebastian Bochmann, Laurent Cagnon, Christophe Thirion, Aurelien Masseboeuf, Eric Mossang, Olivier Fruchart, Julien Bachmann
Summary: The speed and reliability of magnetic domain wall (DW) motion are important for magnetic devices. Extrinsic DW pinning in cylindrical magnetic nanowires is mainly caused by grain boundaries, with spontaneous magnetization and grain size inversely affecting pinning. Other factors like lattice strain and magnetocrystalline anisotropy also play a role.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Astronomy & Astrophysics
Zhi-E Liu, Wen-Fei Liu, Tong-Jie Zhang, Zhong-Xu Zhai, Kamal Bora
Summary: The researchers explored the time variation of the fine structure constant using measurements of galaxy clusters and X-ray observations. By comparing the ratio of YSZDA2 and Y-X, they found that the fine structure constant alpha remains constant with redshift within 3 sigma and 1 sigma for the two samples, respectively. This indicates a robust test on alpha variation.
ASTROPHYSICAL JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
A. Beggas, A. Jraba, M. El Hadi Attia, L. El Mir, E. Elaloui, M. Ghougali, G. Rihia, M. Mourad, M. S. Mahboub
Summary: The present study investigates the influence of immersion time and CO32- concentration on the structural and optical properties of CdS films. Two sets of samples were prepared using chemical bath deposition. The results show that the structural and optical properties of CdS films are significantly affected by immersion time and CO32- concentration.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Weimin Dong, Yingjie Sun, Biao Wang, Mengqi Zhu, Jing Li, Xinguang Xu, Jiyang Wang
Summary: The borate piezoelectric crystal BTBO was grown successfully using the TSSG method. It exhibits high longitudinal piezoelectric coefficient and resistivity, as well as good piezoelectric temperature stability, making it a potential candidate for piezoelectric applications.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Engineering, Mechanical
Murthy N. Guddati, Timothy F. Walsh
Summary: This paper addresses the problem of inverting orthotropic materials from mechanical responses and presents two approaches for parametrizing the modulus tensor. Cholesky parametrization may be better for overall orthotropic inversion, while Alpha parametrization may be more suitable for specific cases. The computational cost is similar for both parametrizations.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Caterina Summonte, Alberto Maurizi, Rita Rizzoli, Fabrizio Tamarri, Monica Bertoldo, Gabriele Bolognini, Piera Maccagnani
Summary: In this study, the reflectance and transmittance spectra of thin gold films on sodium alginate were measured and simulated using the generalized transfer matrix method. The results reveal the structural arrangement of the deposited material on the substrate and the correlation between nanoparticle aggregation and electrical properties. Additionally, this methodology can be applied to other case studies for a comprehensive characterization of the formation process of nanoparticle films on specific substrates.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Multidisciplinary Sciences
Jacob R. Cheeseman, Roland W. Fleming, Filipp Schmidt
Summary: The study found that based on different assumed scales, identical images can be assigned to completely different material categories, indicating that material categorization is susceptible to simple manipulations of apparent distance under challenging conditions.
Article
Engineering, Chemical
Julien Dupas, Florent Baldeweck, Vincent Meunier
Summary: The flow performance of food powders is crucial in product development, as it can affect the dosing and filling processes. This study investigates the influence of various parameters on the flowability of carbohydrate powders, such as particle size and moisture content.
JOURNAL OF FOOD ENGINEERING
(2024)
Article
Optics
Yangyang Guo, Anastasia Borschevsky, Ephraim Eliav, Lukas F. Pasteka
Summary: Theoretical calculations were conducted using the Dirac-Coulomb-Breit relativistic coupled cluster method to predict the electron affinities and ionization potentials of the superheavy element nihonium (Nh) and its lighter homologues In and Tl. The calculations for In and Tl agreed with experimental measurements. For Nh, where experimental data is not available, the predicted ionization potential is 7.569(48) eV and the electron affinity is 0.776(30) eV.
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2022)
Article
Chemistry, Physical
Lea Hegedusova, Rastislav KuteI', Miroslav Medved', Lukas Felix Pasteka, Marek Cigan, Simon Budzak
Summary: In this study, four experimentally characterized phenylazoindoles are studied to determine the mechanism of back-reaction in solvent. Various methods including DFT, TD-DFT, mixed-reference TD-DFT, restricted ensemble Kohn-Sham approaches, CASPT2, and CCSD(T) are employed. The results show that all methods consistently describe the inversion mechanism, while the rotation mechanism requires multireference approaches. The balanced description of both pathways becomes more important in solvent.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Chemistry, Physical
Peter Schwerdtfeger
Summary: This study investigates the dependence of nuclear quadrupole coupling constants CNQC(alpha) on the fine-structure constant alpha for various diatomic gold molecules AuX (X = H, F, Cl, Br, and I) at the density functional level of theory. The results show that the electric field gradient at gold is sensitive to the density functional applied, but the derivative with respect to alpha is less sensitive. The study also estimates the upper limit for the alpha variation in time, dCNQC/dt, at 10-9 Hz/year, which exceeds the limit of high-precision spectroscopy.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Andres Robles-Navarro, Paul Jerabek, Peter Schwerdtfeger
Summary: This study investigates the differences in crystalline structures between Group 1 and Group 11 elements using relativistic density functional theory. The results show that many-body effects, vibrational contributions, and dispersion interactions play a crucial role in explaining these differences.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Arie Landau, Doron Eduardus, Doron Behar, Eliana Ruth Wallach, Lukas F. Pasteka, Shirin Faraji, Anastasia Borschevsky, Yuval Shagam
Summary: Researchers have found suitable candidate molecular ions for studying parity non-conservation (PNC) in chiral molecules using precise molecular spectroscopy methods. These candidates can be generated and detected through specific techniques, meeting the experimental requirements. The results of this study are important for the first-time measurement of PNC in chiral molecules.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Antony Burrows, Shaun Cooper, Peter Schwerdtfeger
Summary: We provide a general lattice sum formula for the hexagonal close packed (hcp) structure with varying c/a ratios, based on previous works by Lennard-Jones, Ingham, Kane, and Goeppert-Mayer. The lattice sum is expressed using fast converging series of Bessel functions. Our analysis reveals a slight symmetry-breaking effect and the appearance of a second metastable minimum for the (12,6) Lennard-Jones potential around the c/a ratio of 2/3, contrasting the ideal ratio of & RADIC;8/3 in the hard-sphere model. Additionally, we demonstrate that extending the (n, m) Lennard-Jones potential through analytical continuation to n, m < 3, such as the Kratzer potential (n = 2, m = 1), produces unphysical results.
Article
Chemistry, Multidisciplinary
Eduardus, Yuval Shagam, Arie Landau, Shirin Faraji, Peter Schwerdtfeger, Anastasia Borschevsky, Lukas F. Pasteka
Summary: The isotopically chiral molecular ion CHDBrI+ is a highly promising candidate for detecting parity violation in vibrational transitions. It exhibits an exceptionally large predicted parity-violating frequency shift for the hydrogen wagging mode, which has a sub-Hz natural line width and falls within the range of available lasers. In contrast, the parent neutral molecule is significantly less sensitive to parity violation. The origin of this effect has been analyzed and explained.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Eduardus, Yuval Shagam, Arie Landau, Shirin Faraji, Peter Schwerdtfeger, Anastasia Borschevsky, Lukas F. Pasteka
Summary: The isotopically chiral molecular ion CHDBrI+ is identified as a promising candidate for detecting parity violation in vibrational transitions. It exhibits a significantly higher sensitivity to parity violation compared to the parent neutral molecule. Precision vibrational spectroscopy of CHDBrI+ is feasible and offers long interrogation times due to its ability to be prepared at internally low temperatures and resistance to predissociation.
CHEMICAL COMMUNICATIONS
(2023)
Article
Physics, Atomic, Molecular & Chemical
Harry Ramanantoanina, Anastasia Borschevsky, Michael Block, Mustapha Laatiaoui
Summary: The reliable energy levels and spectroscopic properties of Lr+ ion and Lu+ homolog were provided using the four-component relativistic Dirac-Coulomb Hamiltonian and the multireference configuration interaction (MRCI) model. The energy spectrum of Lr+ is very similar to that of the Lu+ homolog, which has important implications for experiments with superheavy ions.
Article
Optics
Malika Denis, Pi A. B. Haase, Maarten C. Mooij, Yuly Chamorro, Parul Aggarwal, Hendrick L. Bethlem, Alexander Boeschoten, Anastasia Borschevsky, Kevin Esajas, Yongliang Hao, Steven Hoekstra, Joost W. F. van Hofslot, Virginia R. Marshall, Thomas B. Meijknecht, Rob G. E. Timmermans, Anno Touwen, Wim Ubachs, Lorenz Willmann, Yanning Yin
Summary: We investigated the performance of the relativistic multireference Fock-space coupled-cluster method for predicting molecular hyperfine structure constants and estimated the associated uncertainties through computational studies. The F-19 HFS constant in the ground and excited states of BaF was considered, and the theoretical values showed good overall agreement with recent experimental results within the calculated uncertainties. This work demonstrates the predictive power of the FSCC method and the reliability of the established uncertainty estimates, which is crucial when comparing calculated properties to experiments directly.
