Gravitational Constant Research Articles

An analytical method for increasing the accuracy of the value of the Newtonian constant of gravitation

Despite hundreds of measurements of the Newtonian constant of gravitation, its accuracy remains very low. Over the past 55 years, it has improved by only one order of magnitude - from four to five digits after the decimal point. In this study, a new analytical method for improving the accuracy of estimating the value of the Newtonian constant of gravitation is proposed. Using the proposed method, its accuracy is increased by 7 orders of magnitude relative to the CODATA 2022 data. The method is based on the analytical estimate of the Planck mass, length, and time, with an accuracy of values ​​that is 5 orders of magnitude higher than their accuracy according to CODATA 2022. Such a significant increase in the accuracy of the Planck mass, length, and time values ​​was made possible by the integrated use of: 1) precision formulas for the Planck momentum; 2) representation of the speed of light in a vacuum through the Planck length and time; 3) the De Broglie principle: the moments of the Planck mass, leptons, and baryons are equal to each other; 4) high-precision characteristics of the proton. The method of analytical evaluation of Planck mass, length, and time allowed us to connect the main characteristics of the hypothetical virtual Planck particle with the main characteristics of the proton. Increasing the accuracy of the proton characteristics will entail increasing the accuracy of Planck mass, length, and time. Accordingly, the accuracy of the value of the Newtonian gravitational constant and all physical constants that can be represented through Planck mass, length, and time will be increased, which is especially important in light of the decisions of the 26th General Conference on Weights and Measures.

Neutron Stars constraints on a late G transition

It has been suggested recently that the Hubble tension could be eliminated by a sharp, ∼10% increase of the effective gravitational constant at z∼0.01. This would decrease the luminosities of type 1a supernovae in just the needed amount to explain the larger value of the Hubble parameter. In the present paper we call attention to a dramatic effect of such transition on neutron stars. A neutron star that existed at z=0.01 would contract, conserving the baryon mass but undergoing a mass reduction. We computed neutron star models, with a realistic equation of state, and obtained that this reduction is typically 0.04M⊙. This amounts to an energy of 7×1052 erg. The transition will affect all neutron stars that formed along the history of each galaxy prior to the transition. Given the large number of neutron stars per galaxy, the liberated energy is huge. An estimate of the expected fluxes of neutrinos and x-rays yields values exceeding observational upper limits, thus rendering the late G transition scenario non-viable.

A Coriolis Mechanism Links the Solar Parameters to the Newtonian Gravity

The link between the Newtonian gravity is found to be linked to a Coriolis mechanism between hypothesized gravitons and spinning elementary particles made of gravitons. Inertial resistance is found to be generated by a Coriolis mechanism as well. The Solar parameters are surprisingly well linked to the gravitational constant and the to the velocity of light. The amplitude of this Coriolis mechanism is found to match the Sun’s rotation frequency. The link between the solar parameter, the Newtonian gravity and the found Coriolis mechanism is a key confirmation for the hypothesized gravitons and for the origin of the gravitational constant.

On the Expanding Universe – Accurately Calculate the Hubble Constant by Lunar Laser Ranging

Hubble's Law is an empirical formula. We use the product of the speed of light and time instead of distance for differentiation, and obtain the theoretical differential equation dV=Wdt. Then, the expansion velocity, radius, total mass, singularity radius, and redshift formula of the universe were calculated, and the gravitational constant was derived and proved to be proportional to the fourth power of cosmic time. The mathematical relationship between lunar laser ranging data and Hubble constant was obtained. This is a newly discovered precise method for measuring the Hubble constant

Investigation on hyperbolic Ricci soliton in a perfect fluid spacetime

The aim of this paper is to inspect the geometrical aspects of a perfect fluid spacetime conveying hyperbolic Ricci soliton with torse-forming vector field [Formula: see text]. Next, we have investigated some physical perceptions of perfect fluid spacetime such as dark fluid spacetime, stiff matter fluid spacetime, dust fluid spacetime and radiation fluid spacetime with hyperbolic Ricci soliton in terms of isotropic pressure, the cosmological constant, energy density and gravitational constant. We have also provided two examples of hyperbolic Ricci soliton and hyperbolic Ricci–Bourguignon soliton. Later, we explore the relativistic magneto-fluid spacetime obeying hyperbolic Ricci soliton along with different vector fields.

A note on the Cotton flow and the Ricci flow for three-manifolds, and the Hořava–Lifshitz gravity

We consider the more general geometrical flow in the space of metrics for three-manifolds that consists of a combination of two flows, the Cotton flow and the Ricci flow; by playing a fundamental role in the detailed balance principle of the four dimensional Hořava–Lifshitz gravity, this generalized flow reveals another difficulty with this theory that attempts to be a candidate for an UV completion of Einstein general relativity, namely, the supposed emergency of the speed of light, the Newton constant, and the cosmological constant, from a deeply nonrelativistic theory of gravity. Respecting that principle, the generalized flow shows the proliferation of different limits of the theory with an unwanted behavior at both the IR and UV regimes.

Rogramming the Atoms & Compounds and the Unification of Physics and Chemistry

One of the most important concepts in Geometry is, distance, which is the Quanta in geometry, while in Material-Geometry the composition of Opposite, the Material-Point which is the Quanta in Chemistry and Physics. As in Algebra Zero ,0, is the Master-key number for all Positive and Negative numbers and this because their sum and multiplication become zero, and the same on any coordinate-System where ± axes pass from zero, The Rolling of Positive ⊕, constituent on the Negative ⊝, constituent, creates the Neutral Material Point Which Equilibrium. Angular-Momentum is identical with Spin and consists the First-Discrete-Energy-Monad which occupies, Discrete Value and Direction, in contradiction to the Point which is Nothing, Dimensionless and without any Direction. Quaternion [(+) ↻↺ (-)] ≡ Box which carries the Principal stress σ between A (+), B (-) which σ, as Centripetal-acceleration is the minimum Energy becoming from the in-storage AB acceleration and is equal to the Gravity g. Because of the two different motions, Revolving and Periodic, acceleration of the Gravity g ≡ ± σ exists as the First Energy-Box- ,while in the Second is followed the Local-Extreme-case this acceleration of Gravity g ≡ ± σ, is altered Locally by changing the Principal-stress σ with a Local-uniform-Pressure → ≡ g k = g. [ Force/Area] = G, i.e. The minimum Local - Energy acceleration is the known, Universal Gravitational-constant G = g k = g = σ, for Macrocosm and Microcosm, Obeying Newton`s Laws of motion. It was proved that, Constant G, is the mechanism for the First-kick-Start on the Granular-Energy-monad, g, which Acts in the lightest and less-mass Particle and which is the Hydrogen. The Electron-Nutation-Energy due to g, effect is the minimum frequency ≡ = 2 ,8398447. , and which so exists in all Atoms. This Energy in Hydrogen-Cave as E-M, Conductor ≡ The Pin of Atom-Plug Into their Sockets, which are the Orbit – Bracket – Hooks ≡ The Hands of Atoms, i.e. → The Atoms Plug with their Pins into the other Atoms-Drains = Holes, and so are Bonded. This is the Resonance frequency between all Atoms, and because Hydrogen is Common to all Atoms, so Bond to Molecules and Crystals, and all other Compounds in this Cosmos.

An adaptive gravitational search algorithm for optimizing mechanical engineering design and machining problems

The gravitational search algorithm (GSA) is widely used for solving optimization problems because it performs in a superior manner as compared to various competing evolutionary and swarm-based metaheuristics. However, GSA frequently gets trapped in local optima due to a lack of solution diversity. Although chaotic gravitational search algorithm (CGSA) can resolve this issue to some extent but its degraded exploitation rate and convergence speed may not result in desired outcome. To this end, diversity-based chaotic GSA (DCGSA) has exhibited its capability to resolve the issues encountered with GSA and CGSA to a certain extent for unconstrained problems. DCGSA achieves this characteristic through the use of an adaptive gravitational constant, which varies according to the diversity values of the population. Since most real-world problems are subjected to some constraints, it is prudent to improve the performance of GSA in solving constrained optimization problems. The present study integrates the enhanced search capability of DCGSA with a generalized constraint handling mechanism to improve the performance of GSA in solving constrained problems. It is observed that DCGSA significantly outperforms GSA on both CEC (Congress on evolutionary computation) 2006, 2010 and 2017 functions and competes strongly with CGSA. Diversity analysis shows that the capability to balance exploration and exploitation rates is enhanced using CGSA and DCGSA. Furthermore, DCGSA algorithms outperform GSA and CGSA on real-world machining and CEC 2020 mechanical design problems. Comparison with state-of-the-art algorithms is made to analyze the performance of the algorithms from a larger perspective.

Conformal structure of singularities in some varying fundamental constants bimetric cosmologies

In this paper, we explore the conformal structure of singularities arising from varying fundamental constants using the method of Penrose diagrams. We employ a specific type of bimetric model featuring two different metrics. One metric describes the causal structure for matter, while the other characterizes the causal structure for gravitational interactions, which is related to variations in fundamental constants such as the gravitational constant and the speed of light. For this reason, we focused on the gravitational metric to calculate the conformal transformation and compose Penrose diagrams for the singularities arising from the varying fundamental constants. We have shown that, in one case, the parameter such as the scale factor, the density and the pressure resemble those of the finite scale factor singularity (FSF). Despite singularity appears in constant conformal time in our case and in the case of FSF the Misner-Sharp horizon looks different. Our another case is similar to sudden future singularity (SFS), but there are differences in the conformal structures. We have also shown that in our cases the behavior of Misner-Sharp horizon strongly depends on initial conditions. The last analytical solution which we introduced is identical to conformal structure of the standard exotic singularity for the matter.

A simple prediction of the nonlinear matter power spectrum in Brans–Dicke gravity from linear theory

Brans–Dicke (BD), one of the first proposed scalar-tensor theories of gravity, effectively makes the gravitational constant of general relativity (GR) time-dependent. Constraints on the BD parameter ω serve as a benchmark for testing GR, which is recovered in the limit ω → ∞. Current small-scale astrophysical constraints ω ≳ 105 are much tighter than large-scale cosmological constraints ω ≳ 103, but the two decouple if the true theory of gravity features screening. On the largest cosmological scales, BD approximates the most general second-order scalar–tensor (Horndeski) theory, so constraints here have wider implications. These constraints will improve with upcoming large-scale structure and cosmic microwave background surveys. To constrain BD with weak gravitational lensing, one needs its nonlinear matter power spectrum PBD. By comparing the boost B = PBD/PGR from linear theory and nonlinear N-body simulations, we show that the nonlinear boost can simply be predicted from linear theory if the BD and GR universes are parameterized in a way that makes their early cosmological evolution and quasilinear power today similar. In particular, they need the same H0/√Geff(a = 0) and σ8, where Geff is the (effective) gravitational strength. Our prediction is 1% accurate for ω ≥ 100, z ≤ 3, and k ≤ 1 h/Mpc; and 2% up to k ≤ 5 h/Mpc. It also holds for GBD that do not match Newton’s constant today, so one can study GR with different gravitational constants GGR by sending ω → ∞. We provide a code that computes B with the linear Einstein-Boltzmann solver HI_CLASS and multiplies it by the nonlinear PGR from EUCLIDEMULATOR2 to predict PBD.

Gravitational Field of a Self-Gravitating Continuous Medium and Dark Matter

A method to describe the hidden mass effect or dark matter has been proposed on the basis of a new general solution of the Poisson equation for the gravitational field strength in a continuous self-gravitating medium. This solution is a consequence of the theory of space and matter alternative to the general relativity. Conditions have been derived to distinguish between the cases where the obtained solution describes the classical Newtonian gravitational field and the cases where this solution leads to the hidden mass effect. The representation obtained for the gravitational field strength has been analyzed within the model of the dynamic equilibrium of disk galaxies and the possibility of describing the observed properties of the hidden mass effect within this approach has been discussed.

Understanding the natural units and their hidden role in the laws of physics

The natural units of measure lauded by Max Planck more than 100 years ago are underutilized today. Many physical constants, including the Planck constant, the gravitational constant, the speed of light, vacuum permittivity, and vacuum permeability consist of natural units in their unit dimensions. The natural units are present in all formulas containing these constants. The defining characteristic of the natural units is an alignment of unit values at the Planck scale. This alignment gives a computational basis of proportionality from which the correlated properties and dynamics of elementary particles, including wavelength, period, mass, momentum, and energy, manifest in equal or inversely proportional ratios of the Planck scale. These correlations explain many of the defining equations of quantum mechanics, classical gravity, and electromagnetism.

Kerr-MOG-(A)dS black hole and its shadow in scalar-tensor-vector gravity theory

The scalar-tensor-vector gravity (STVG) theory has attracted significant interest due to its ability to effectively address the issue of galaxy rotation curves and clusters of galaxies without considering the influence of dark matter. In this paper, we construct rotating black hole solutions with a cosmological constant in the STVG theory (i.e., Kerr-MOG-(A)dS black hole solutions), where the import of a gravitational charge as a source modifies the gravitational constant, determined by GG = G N(1+α). For Kerr-MOG-dS spacetime, the observer is situated at a specific location within the domain of outer communication, rather than being located infinitely far away. Since black hole shadows are shaped by light propagation in spacetime, the interaction between the MOG parameter and the cosmological constant is expected to produce novel effects on these shadows. As the cosmological constant Λ increases, the apparent size of the black hole shadow decreases. Additionally, the shadow expands with an increase in the MOG parameter α, reaching a maximum at a certain value, and its shape becomes more rounded under an arbitrary rotation parameter, which leads to degeneracy between different black hole parameters. However, by employing numerical ray-tracing techniques, we have found that gravitational lensing and the frame-dragging effect effectively distinguish this degeneracy. Our work contributes to a deeper understanding of black holes in modified gravity, their observational signatures, and constraints.

Phase transition and central charge criticality of RN AdS black hole immersed in perfect fluid dark matter

This paper delves into the thermodynamic properties of RN AdS black hole immersed in perfect fluid dark matter. We vary the Newton’s gravitational constant, cosmological constant and the perfect fluid dark matter parameter in the bulk. When studying the first law of thermodynamics for black holes, the boundary conformal field theory introduces the central charge, leading to modifications in the thermodynamic volume and chemical potential of black hole. Our analysis shows that the black hole’s free energy is affected by changes in both the central charge and the parameter of perfect fluid dark matter. The F−T curve shows a swallowtail behavior when central charge is above a critical value, which means the occurrence of first-order phase transition from a small black hole to a large black hole. Additionally, we analyzed the heat capacity as a function of temperature for different PFDM parameter values to study the stability of the black hole.

Observational constraints on FLRW, Bianchi type I and V brane models

This study explores the compatibility of Covariant Extrinsic Gravity (CEG), a braneworld scenario with an arbitrary number of non-compact extra dimensions, with current cosmological observations. We employ the chi-square statistic and Markov Chain Monte Carlo (MCMC) methods to fit the Friedmann–Lemaître–Robertson–Walker (FLRW) and Bianchi type-I and V brane models to the latest datasets, including Hubble, Pantheon+ Supernova samples, Big Bang Nucleosynthesis (BBN), Baryon Acoustic Oscillations (BAO), and the structure growth rate, fσ8(z). Parameters for FLRW universe consist Ω0(b),Ω0(cd),Ω0(k),H0,γ,σ8, while for the Bianchi model are Ω0(b),Ω0(cd),Ω0(β),H0,γ,Ω0(θ),σ8. By comparing our models to observational data, we determine the best values for cosmological parameters. For the FLRW model, these values depend on the sign of γ (which gives the time variation of gravitational constant in Hubble time unit): γ>0 yields γ=0.00008−0.00011+0.00015, and Ω0(k)=0.014−0.022+0.024 and γ<0 leads to γ=−0.0226−0.0062+0.0054, and Ω0(k)=0.023−0.041+0.039. It should be noted that in both cases Ω0(k)>0, which represents a closed universe. Similarly, for the Bianchi type-V brane model, the parameter values vary with the sign of γ, resulting in γ=0.00084−0.00021+0.00019, Ω0(β)=0.0258−0.0063+0.0052, and Ω0θ(×10−5)=4.19−0.75+0.67 (as with the density parameter of stiff matter) for γ>0, and γ=−0.00107−0.00020+0.00019, Ω0(β)=0.0259−0.0062+0.0050, and Ω0θ(×10−5)=4.17−0.98+0.91 for γ<0. In both cases Ω0(β)>0, which represents the Bianchi type-V, because in the Bianchi type-I, β=0. Subsequently, utilizing these obtained best values, we analyze the behavior of key cosmological parameters such as the Hubble parameter, deceleration parameter, distance modulus, equation of state, and density parameters that characterize both matter and the geometric component of dark energy, as functions of redshift. Our results notably show that the FLRW model with γ<0 is more compatible with observational data than the Bianchi model, based on various statistical criteria.

Local thermodynamics and entropy for relativistic hydrostatic equilibrium

By refining the method proposed in Aoki et al. (2021) [5], entropy current and entropy density for a relativistic hydrostatic equilibrium system with spherical symmetry are constructed as a non-Nöther conserved charge in the Einstein gravity with cosmological constant. It is shown that the constructed entropy density satisfies both the local Euler relation and the first law of thermodynamics non-perturbatively with respect to the Newton constant. Finally the established relativistic thermodynamics is applied to one of the systems with uniform energy density as a crude model of a degenerate star and its local thermodynamic observables are determined analytically.

Exploring secular variation of the gravitational constant from high-resolution quasar spectra

The exploration of potential variations in fundamental physical constants is crucial for testing of Grand Unification Theories (GUTs), which aim to unify the fundamental forces of nature. This study utilizes direct observational tests to explore these variations, offering a deep-look into the universe's distant past. By analyzing high-resolution quasar spectra of HE 0515–4414* and comparing them with laboratory-calibrated Ritz wavelengths, we establish an upper limit on the possible cosmological deviation of the gravitational constant: G˙/G=(0.918±2.830)×10-15yr-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\dot{\ ext{G}}/\ ext{G}=(0.918 \\pm 2.830)\ imes {10}^{-15}{\ ext{ yr}}^{-1}$$\\end{document} over cosmic timescales. Our findings provide a novel tool for probing the physical implications of GUTs, contributing to our understanding of fundamental physics.

Controllable quantum walks, gravitational constant, and Casimir energy in one-dimensional three-boson systems with on-site interactions

Controllable quantum walks, gravitational constant, and Casimir energy in one-dimensional three-boson systems with on-site interactions

The Divine Blueprint: An In-Deth Analysis of the Quran’s Mathematical Architecture -Revealing the Golden Ratio, Solar Year Length, Universal GravitationalConstant, Speedof Light, Planck Constant, and theSignificance of the Numbers 28 and 114

There is a strong belief that Allah Almighty could reveal His existence by encoding the laws of nature and their fundamental constants in the Quran with impeccable precision. However, the mathematical frameworks and patterns embedded within the Quranic text to reveal scientific laws and constants may contain minor deviations in numerical values to empower personal exploration, accommodate diverse interpretations, and strengthen faith. This theory is based on the fact that the Quran is the word of Allah Almighty. Consequently, one would anticipate finding evidence suggesting a divine origin. Many scholars and researchers have suggested that this evidence can be found in the mathematical structure of the Quran through patterns, numerical codes, and other mathematical features within the text that are too complex to be simply attributed to human authorship. Therefore, it is believed that the Quran contains within its structure a mathematical encoding of all physical laws and constants. Verses like 20.98, which state, "He encompasses all things in knowledge," are quoted as evidence. According to this perspective, the Quran is assumed to incorporate mathematical miracles, indicating a potential correspondence between its text and the underlying order of the universe. This theory reveals many mathematical frameworks illustrating how the Quran embeds scientific knowledge. These include the identification of frequent occurrences of the golden ratio within the Quranic text and the manifestation of the golden ratio in the human body, alongside the determination of key celestial parameters such as the length of the solar year. Furthermore, this theory uncovers a numerical link between the Quran and fundamental scientific constants, notably the universal gravitational constant, the speed of light, and the Planck constant. Moreover, this theory utilizes numerical analysis to offer a compelling rationale for why the numbers 28 and 114 are used to represent the total number of Arabic letters and chapters in the Quran, respectively. Finally, this theory highlights the Quran's remarkable mathematical architecture, offering indisputable evidence of its divine composition. We behold a mathematical marvel of cosmic scale, a phenomenon defying human intelligence. Indeed, the Quranis a product of a super intelligence exceeding our comprehension.

Schwarzschild Black Hole from Perturbation Theory to All Orders.

Applying the quantum field theoretic perturbiner approach to Einstein gravity, we compute the metric of a Schwarzschild black hole order by order in perturbation theory. Using recursion, this calculation can be carried out in de Donder gauge to all orders in Newton's constant. The result is a geometric series which is convergent outside a disk of finite radius, and it agrees within its region of convergence with the known de Donder gauge metric of a Schwarzschild black hole. It thus provides a first all-order perturbative computation in Einstein gravity with a matter source, and this series converges to the known nonperturbative expression in the expected range of convergence.