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Journal articles on the topic 'Gravity derivatives'

Author: Grafiati

Published: 2 June 2025

Last updated: 31 July 2025

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1

Zuhdi, Muhammad, Bakti Sukrisna, and Syamsuddin Syamsuddin. "IDENTIFICATION OF BURIED ARCHEOLOGICAL OBJECTS WITH RADIAL DERIVATIVES OF MICRO GRAVITY DATA." Indonesian Physical Review 2, no. 2 (2019): 84. http://dx.doi.org/10.29303/ipr.v2i2.25.

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The development of recent gravimetric technology allows us to measure gravity anomalies with accuracy of micro Gal. Micro gravity is able to detect very small gravity anomalies such as anomaly due to buried archeological objects below the earth surface. Radial Derivatives of gravity data is used to sharpen anomaly due to lateral changes of density contrast. Horizontal derivatives carried out by previous researchers have some weaknesses, i.e. the loss of derivative values in certain directions and inconsistence values at the source boundary of the same anomaly edge. To solve the horizontal deri

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2

Slovick, Brian. "Renormalization of Einstein gravity through a derivative-dependent field redefinition." Modern Physics Letters A 33, no. 02 (2018): 1850016. http://dx.doi.org/10.1142/s0217732318500165.

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This work explores an alternative solution to the problem of renormalizability in Einstein gravity. In the proposed approach, Einstein gravity is transformed into the renormalizable theory of four-derivative gravity by applying a local field redefinition containing an infinite number of higher derivatives. It is also shown that the current–current amplitude is invariant with the field redefinition, and thus the unitarity of Einstein gravity is preserved.

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Isgаndаrov, E., A. Mammadov, and J. Maliyeva. "FILTRATION OF THE GRAVITATIONAL FIELD OF THE ABSHERON-BALKHAN AREA." POLISH JOURNAL OF SCIENCE, no. 86 (May 23, 2025): 22–28. https://doi.org/10.5281/zenodo.15494150.

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The article considers the issue of filtering the gravity field using derivative and gradient methods, which are highly sensitive in identifying weak local anomalies, gravity gradient zones, marginal parts of structures, deep faults and disturbances. As is known, these anomalies also display density heterogeneities of rocks, which can be associated with oil and gas fields and other minerals. Recently, various modifications and formulas for calculating gradients and derivatives of different orientations have been developed, which emphasize various features of anomaly-forming geological structure

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4

Zuhdi, Muhammad, Syahrial Ayub, and Syamsuddin Syamsuddin. "Forward Modeling of Gravity Anomalies for Identification of Burried Cylindrical Body Using Radial Derivative." Jurnal Pendidikan Fisika dan Teknologi 10, no. 1 (2024): 192–99. http://dx.doi.org/10.29303/jpft.v10i1.7077.

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Radial Derivative Forward Modeling of Gravity Anomalies for Identification of Cylindrical Geological Features. The gravity method is a geophysical method with exploration costs that are quite cheap compared to other geophysical methods. This method is based on the density contrast of the target body with the surrounding. The cylindrical body is one of the targets among various other geological features. This research was conducted to test the ability of radial derivatives of gravity anomalies for targets in the form of cylindrical body. Radial derivatives consist of a first derivative and a se

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5

Tomboulis, E. T. "Renormalization and unitarity in higher derivative and nonlocal gravity theories." Modern Physics Letters A 30, no. 03n04 (2015): 1540005. http://dx.doi.org/10.1142/s0217732315400052.

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We review and discuss higher derivative and nonlocal theories of quantum gravity focusing on their UV and unitarity properties. We first consider the general fourth-order gravitational action, then actions containing derivatives up to any given fixed order, and discuss their UV divergences, fixed points and concomitant unitarity issues. This leads to a more general discussion of "asymptotic safety" and unitarity, which motivates the introduction of nonlocal theories containing derivatives to all orders arising from the expansion of entire functions. For such theories good UV behavior is visibl

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Biswas, Tirthabir, and Spyridon Talaganis. "String-inspired infinite-derivative theories of gravity: A brief overview." Modern Physics Letters A 30, no. 03n04 (2015): 1540009. http://dx.doi.org/10.1142/s021773231540009x.

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In String Theory, there often appears a rather interesting class of higher derivative theories containing an infinite set of derivatives in the form of an exponential. These theories may provide a way to tame ultraviolet (UV) divergences without introducing ghost-like states. Here we provide a brief overview on the progress that has been made over the last decade to construct such infinite-derivative theories of gravity (IDG) which may be able to address the singularity problems in gravity. In the process, we will present some general results that applies to covariant torsion-free metric theor

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7

Asorey, M., J. L. López, and I. L. Shapiro. "Some Remarks on High Derivative Quantum Gravity." International Journal of Modern Physics A 12, no. 32 (1997): 5711–34. http://dx.doi.org/10.1142/s0217751x97002991.

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We analyze the perturbative implications of the most general high derivative approach to quantum gravity based on a diffeomorphism-invariant local action. In particular, we consider the superrenormalizable case with a large number of metric derivatives in the action. The structure of ultraviolet divergences is analyzed in some detail. We show that they are independent of the gauge-fixing condition and the choice of field reparametrization. The cosmological counterterm is shown to vanish under certain parameter conditions. We elaborate on the unitarity problem of high derivative approaches and

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8

Ming, Yanbo, Guoqing Ma, Lili Li, Jiangtao Han, and Taihan Wang. "The Spatial Different Order Derivative Method of Gravity and Magnetic Anomalies for Source Distribution Inversion." Remote Sensing 13, no. 5 (2021): 964. http://dx.doi.org/10.3390/rs13050964.

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Gravity and magnetic measurements are common remote sensing strategies to obtain the property change of observed targets. Nowadays, the characteristic value of the derivatives of gravity and magnetic anomalies is commonly used to detect the source horizontal edge. We found that the horizontal coordinates of the characteristic value of different-order derivatives are not directly corresponding to the edge of the source, which varies with the depth and size of the source. The spatial different-order derivative (SDD) method of gravity and magnetic anomalies was developed, and we proved that the s

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9

Muhammad, Zuhdi, Sismanto, Setiawan Ari, Setyowiyoto Jarot, Susilo Adi, and Sarkowi Muhammad. "Radial Derivative and Radial Inversion for Interpreting 4D Gravity Anomaly Due to Fluids Injection Around Reservoir." TELKOMNIKA Telecommunication, Computing, Electronics and Control 16, no. 6 (2018): 2855–63. https://doi.org/10.12928/TELKOMNIKA.v16i6.9468.

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The 4D gravity or time lapse gravity has been used many reseracher to identify fluid injection in oil reservoir. The objective of this study is to find the better way in interpreting 4D gravity anomaly due to fluid injection around the reservoir. Radial Derivatives are derivative values of gravity anomalies against horizontal distances in the radial direction. Radial inversion is a two-dimensional inversion of lines with radial directions resulting in a 3-dimension model. Time lapse microgravity research have been performed in “X Oil Field” with amount of 604 data point covering ar

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10

Gupta, O. P. "Reply by the author to E. M. Abdelrahman, A. I. Bayoumi, and Y. A. Amin." GEOPHYSICS 50, no. 2 (1985): 263. http://dx.doi.org/10.1190/1.1486947.

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I agree with Abdelrahman et al. The use of horizontal derivatives to estimate the depth was tried by one of my colleagues and was found to have the added advantage of resolving structural ambiguities. Formulas for derivatives can be obtained in a similar way as given in the subject paper by simply taking the derivative of the function described by relation (1). However, one has to be very careful in obtaining the derivatives, numerically, from conventional gravity survey data. Estimation of depth will be more reliable. I feel, if derivatives can be measured in field directly, which is a subjec

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11

Debeglia, Nicole, and Jacques Corpel. "Automatic 3-D interpretation of potential field data using analytic signal derivatives." GEOPHYSICS 62, no. 1 (1997): 87–96. http://dx.doi.org/10.1190/1.1444149.

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A new method has been developed for the automatic and general interpretation of gravity and magnetic data. This technique, based on the analysis of 3-D analytic signal derivatives, involves as few assumptions as possible on the magnetization or density properties and on the geometry of the structures. It is therefore particularly well suited to preliminary interpretation and model initialization. Processing the derivatives of the analytic signal amplitude, instead of the original analytic signal amplitude, gives a more efficient separation of anomalies caused by close structures. Moreover, gra

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12

Aydın, Ömer Lütfü, Ozcan Bektas, Aydın Büyüksaraç, and Hüseyin Yılmaz. "3D Modeling and Tectonic Interpretation of the Erzincan Basin (Turkey) using Potential Field Data." Earth Sciences Research Journal 23, no. 1 (2019): 57–66. http://dx.doi.org/10.15446/esrj.v23n1.71090.

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Erzincan Basin was investigated using gravity data within the scope of this study. It is also aimed to reveal the discontinuities in the work area as well as the buried discontinuities. Boundary determination filters and analysis of the structure of the data and its connection are revealed and clear information is obtained. Gravity anomalies were applied with an upward continuation method for 0.25, 0.50, 0.75 and 1 km levels. Total Horizontal Derivative (THD) filter, Analytical Signal (AS) filter, Tilt Angle Derivative (Tilt) filter, Total Horizontal Derivative (THDR) filter, Theta Angle Deriv

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13

Du, Wei, and Yangyang Zhang. "The Calculation of High-Order Vertical Derivative in Gravity Field by Tikhonov Regularization Iterative Method." Mathematical Problems in Engineering 2021 (May 8, 2021): 1–13. http://dx.doi.org/10.1155/2021/8818552.

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In mathematics, statistics, and computer science, particularly in the fields of machine learning and inverse problems, regularization is a process of introducing additional information in order to solve an ill-posed problem or to prevent overfitting. The Tikhonov regularization method is widely used to solve complex problems in engineering. The vertical derivative of gravity can highlight the local anomalies and separate the horizontal superimposed abnormal bodies. The higher the order of the vertical derivative is, the stronger the resolution is. However, it is generally considered that the c

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14

Jia, Zhen, and Shiguo Wu. "Potential fields and their partial derivatives produced by a 2D homogeneous polygonal source: A summary with some revisions." GEOPHYSICS 76, no. 4 (2011): L29—L34. http://dx.doi.org/10.1190/1.3587221.

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We summarized and revised the present forward modeling methods for calculating the gravity- and magnetic-field components and their partial derivatives of a 2D homogeneous source with a polygonal cross section. The responses of interest include the gravity-field components and their first- and second-order partial derivatives and the magnetic-field components and their first-order partial derivatives. The revised formulas consist of several basic quantities that are common in all the formulations. A singularity appears when the observation point coincides with a polygon vertex. This singularit

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15

Rachwał, Lesław. "How to understand the structure of beta functions in six-derivative Quantum Gravity?" Acta Polytechnica 62, no. 1 (2022): 118–56. http://dx.doi.org/10.14311/ap.2022.62.0118.

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We extensively motivate the studies of higher-derivative gravities, and in particular we emphasize which new quantum features theories with six derivatives in their definitions possess. Next, we discuss the mathematical structure of the exact on the full quantum level beta functions obtained previously for three couplings in front of generally covariant terms with four derivatives (Weyl tensor squared, Ricci scalar squared and the Gauss-Bonnet scalar) in minimal six-derivative quantum gravity in d = 4 spacetime dimensions. The fundamental role here is played by the ratio x of the coupling in f

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16

Sorokin, N. A. "Earth's gravity field parameters determination by the space geodesy dynamical approach." Geodesy and Cartography 919, no. 1 (2017): 7–12. http://dx.doi.org/10.22389/0016-7126-2017-919-1-7-12.

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The method of the geopotential parameters determination with the use of the gradiometry data is considered. The second derivative of the gravitational potential in the correction equation on the rectangular coordinates x, y, z is used as a measured variable. For the calculated value of the measured quantity required for the formation of a free member of the correction equation, the the Cunningham polynomials were used. We give algorithms for computing the second derivatives of the Cunningham polynomials on rectangular coordinates x, y, z, which allow to calculate the second derivatives of the

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17

Kwok, Yue‐Kuen. "Conjugate complex variables method for the computation of gravity anomalies." GEOPHYSICS 54, no. 12 (1989): 1629–37. http://dx.doi.org/10.1190/1.1442631.

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Using conjugate complex variables, a generalized method is presented to derive formulas to calculate first‐ and higher‐order derivatives of the gravity potential due to selected mass models. Double integrals in the computation of gravity‐gradient anomalies are transformed into complex contour integrals. Analytical expressions for higher‐order derivatives of the gravitational potential in arbitrary directions due to two‐dimensional (2‐D) polygonal mass models are derived. The method is extended to 2‐D polygonal bodies whose density contrasts vary with depth and horizontal distance and can be ge

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18

Nguyen, Nhu Trung, Van Kha Tran, and Van Nam Bui. "Determination of vertical derivative of gravity anomalous by upward continuation and Taylor series transform methods: application to the Southwest sub-basin of the East Vietnam Sea." Tạp chí Khoa học và Công nghệ Biển 22, no. 2 (2022): 133–42. http://dx.doi.org/10.15625/1859-3097/17233.

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The vertical derivative of the gravity anomaly has a vital role in the methods of geological structure research such as determining fault systems and the location of the field sources. In addition, the vertical derivative is also used to calculate the downward continuation and further clarify the image of the seabed topography. However, determining the vertical derivative according to the traditional Fast Fourier Transform (FFT) method is often unstable and has low accuracy in high-order derivatives for high noise actual data. In this article, we introduce a new calculation method to determine

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19

Lee, Kiyoung, and Warren Siegel. "Bound-state gravity from higher derivatives." Nuclear Physics B 665 (August 2003): 179–88. http://dx.doi.org/10.1016/s0550-3213(03)00488-7.

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20

Heredia, Carlos, Ivan Kolář, Josep Llosa, Francisco José Maldonado Torralba, and Anupam Mazumdar. "Infinite-derivative linearized gravity in convolutional form." Classical and Quantum Gravity 39, no. 8 (2022): 085001. http://dx.doi.org/10.1088/1361-6382/ac5a14.

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Abstract This article aims to transform the infinite-order Lagrangian density for ghost-free infinite-derivative linearized gravity into non-local form. To achieve it, we use the theory of generalized functions and the Fourier transform in the space of tempered distributions S ′ . We show that the non-local operator domain is not defined on the whole functional space but on a subset of it. Moreover, we prove that these functions and their derivatives are bounded in all R 3 and, consequently, the Riemann tensor is regular and the scalar curvature invariants do not present any spacetime singular

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21

Maranan, Melchor C., and Marie-Pierre G. Laborie. "Analysis of Energy Traits of Populus spp. Clones by Near-Infrared Spectroscopy." Journal of Biobased Materials and Bioenergy 1, no. 1 (2007): 155–62. http://dx.doi.org/10.1166/jbmb.2007.1989.

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The application of near-infrared spectroscopy (NIRS) and multivariate analysis for determining the calorific value and specific gravity of Populus spp. clones was assessed. Projection to latent structure (PLS) models of calorific value and specific gravity were developed from NIR original spectra and also from the first and second spectral derivatives. The best calibration models were built from the NIR second spectral derivative with good calibration statistics for both calorific value (r = 0 97, RMSEC = 0 05 kJ/g) and specific gravity (r = 0 98; RMSEC = 0 005). The calibration models from th

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22

Katsoulas, Theodoros, and Kyriakos Tamvakis. "General Einstein-Cartan quadratic gravity with derivative couplings." Journal of Cosmology and Astroparticle Physics 2025, no. 06 (2025): 022. https://doi.org/10.1088/1475-7516/2025/06/022.

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Abstract Within the framework of Einstein-Cartan gravity we consider an action, containing up to quadratic terms of the Ricci scalar and the Holst invariant, coupled non-minimally to a scalar field, including couplings of its derivatives to curvature. We derive the equivalent metric theory, featuring an extra dynamical pseudoscalar degree of freedom associated with the presence of the Holst term in the action. We study the evolution of the resulting two-field system in a FRW background and show that it evolves rapidly into an effective single-field inflationary model. We find that the model is

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23

Rubin, Sergey G., Arkadiy Popov, and Polina M. Petriakova. "Gravity with Higher Derivatives in D-Dimensions." Universe 6, no. 10 (2020): 187. http://dx.doi.org/10.3390/universe6100187.

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The aim of this review is to discuss the ways to obtain results based on gravity with higher derivatives in D-dimensional world. We considered the following ways: (1) reduction to scalar tensor gravity, (2) direct solution of the equations of motion, (3) derivation of approximate equations in the presence of a small parameter in the system, and (4) the method of test functions. Some applications are presented to illustrate each method. The unification of two necessary elements of a future theory is also kept in mind—the extra dimensions and the extended form of the gravity.

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Shapiro, Ilya L., Ana M. Pelinson, and Filipe de O. Salles. "Gravitational waves and perspectives for quantum gravity." Modern Physics Letters A 29, no. 30 (2014): 1430034. http://dx.doi.org/10.1142/s0217732314300341.

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Understanding the role of higher derivatives is probably one of the most relevant questions in quantum gravity theory. Already at the semiclassical level, when gravity is a classical background for quantum matter fields, the action of gravity should include fourth derivative terms to provide renormalizability in the vacuum sector. The same situation holds in the quantum theory of metric. At the same time, including the fourth derivative terms means the presence of massive ghosts, which are gauge-independent massive states with negative kinetic energy. At both classical and quantum level such g

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Baldazzi, Alessio, and Kevin Falls. "Essential Quantum Einstein Gravity." Universe 7, no. 8 (2021): 294. http://dx.doi.org/10.3390/universe7080294.

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The non-perturbative renormalisation of quantum gravity is investigated allowing for the metric to be reparameterised along the RG flow, such that only the essential couplings constants are renormalised. This allows us to identify a universality class of quantum gravity which is guaranteed to be unitary, since the physical degrees of freedom are those of general relativity without matter and with a vanishing cosmological constant. Considering all diffeomorphism invariant operators with up to four derivatives, only Newton’s constant is essential at the Gaussian infrared fixed point associated t

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26

Salvio, Alberto. "Dimensional transmutation in gravity and cosmology." International Journal of Modern Physics A 36, no. 08n09 (2021): 2130006. http://dx.doi.org/10.1142/s0217751x21300064.

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We review (and extend) the analysis of general theories of all interactions (gravity included) where the mass scales are due to dimensional transmutation. Quantum consistency requires the presence of terms in the action with four derivatives of the metric. It is shown, nevertheless, how unitary is achieved and the classical Ostrogradsky instabilities can be avoided. The four-derivative terms also allow us to have a UV complete framework and a naturally small ratio between the Higgs mass and the Planck scale. Moreover, black holes of Einstein gravity with horizons smaller than a certain (micros

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27

Helfer, A. D. "Spinor Lie derivatives and Fermion stress–energies." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2186 (2016): 20150757. http://dx.doi.org/10.1098/rspa.2015.0757.

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Stress–energies for Fermi fields are derived from the principle of general covariance. This is done by developing a notion of Lie derivatives of spinors along arbitrary vector fields. A substantial theory of such derivatives was first introduced by Kosmann; here, I show how an apparent conflict in the literature on this is due to a difference in the definitions of spinors, and that tracking the Lie derivative of the Infeld–van der Waerden symbol, as well as the spinor fields under consideration, gives a fuller picture of the geometry and leads to the Fermion stress–energy. The differences in t

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28

Beiki, Majid. "Analytic signals of gravity gradient tensor and their application to estimate source location." GEOPHYSICS 75, no. 6 (2010): I59—I74. http://dx.doi.org/10.1190/1.3493639.

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The analytic signal concept can be applied to gravity gradient tensor data in three dimensions. Within the gravity gradient tensor, the horizontal and vertical derivatives of gravity vector components are Hilbert transform pairs. Three analytic signal functions then are introduced along [Formula: see text]-, [Formula: see text]-, and [Formula: see text]-directions. The amplitude of the first vertical derivative of the analytic signals in [Formula: see text]- and [Formula: see text]-directions enhances the edges of causative bodies. The directional analytic signals are homogenous and satisfy Eu

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Fabris, Júlio C., Arkady A. Popov, and Sergey G. Rubin. "Multidimensional gravity with higher derivatives and inflation." Physics Letters B 806 (July 2020): 135458. http://dx.doi.org/10.1016/j.physletb.2020.135458.

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Schreiter, Lucas, Daniel Arnold, Veerle Sterken, and Adrian Jäggi. "Mitigation of ionospheric signatures in Swarm GPS gravity field estimation using weighting strategies." Annales Geophysicae 37, no. 1 (2019): 111–27. http://dx.doi.org/10.5194/angeo-37-111-2019.

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Abstract. Even though ESA's three-satellite low-earth orbit (LEO) mission Swarm is primarily a magnetic field mission, it can also serve as a gravity field mission. Located in a near-polar orbit with initial altitudes of 480 km for Swarm A and Swarm C and 530 km for Swarm B and equipped with geodetic-type dual frequency Global Positioning System (GPS) receivers, it is suitable for gravity field computation. Of course, the Swarm GPS-only gravity fields cannot compete with the gravity fields derived from the ultra-precise Gravity Recovery And Climate Experiment (GRACE) K-band measurements. But f

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Glavan, Dražen, Shinji Mukohyama, and Tom Zlosnik. "Removing spurious degrees of freedom from EFT of gravity." Journal of Cosmology and Astroparticle Physics 2025, no. 01 (2025): 111. https://doi.org/10.1088/1475-7516/2025/01/111.

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Abstract In the effective field theory approach to gravity, the Lagrangian density for general relativity is supplemented by generally covariant terms of higher order in the Riemann tensor and its derivatives. At face value, these terms will result in higher derivative equations of motion and additional degrees of freedom beyond those of general relativity. This is seemingly at odds with the goal of effective field theory which is to encode ultraviolet corrections in terms of existing low energy degrees of freedom. Here we apply an action-based procedure for the removal of spurious degrees of

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Сергазина, Альмира. "Gravitational Redshift in Generalized Gravity Models." BULLETIN OF THE L.N. GUMILYOV EURASIAN NATIONAL UNIVERSITY. PHYSICS. ASTRONOMY SERIES 151, no. 2 (2025): 23–31. https://doi.org/10.32523/2616-6836-2025-151-2-23-31.

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This paper explores the phenomenon of gravitational redshift within the framework of extended gravity models, which go beyond the conventional Einsteinian General Relativity. We establish a relationship between the redshift and the normalized scale factor of the universe, linking it through the Hubble parameter .We develop both analytical and numerical approaches to examine the time evolution of redshift. By solving the governing equations, we derive expressions for , and their derivatives with respect to time. The results align with current cosmological observations and provide new insights i

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Baker, Mark Robert, and Sergei Kuzmin. "A connection between linearized Gauss–Bonnet gravity and classical electrodynamics." International Journal of Modern Physics D 28, no. 07 (2019): 1950092. http://dx.doi.org/10.1142/s0218271819500925.

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A connection between linearized Gauss–Bonnet gravity and classical electrodynamics is found by developing a procedure which can be used to derive completely gauge-invariant models. The procedure involves building the most general Lagrangian for a particular order of derivatives ([Formula: see text]) and a rank of tensor potential ([Formula: see text]), then solving such that the model is completely gauge-invariant (the Lagrangian density, equation of motion and energy–momentum tensor are all gauge-invariant). In the case of [Formula: see text] order of derivatives and [Formula: see text] rank

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Salem, Ahmed, Dhananjay Ravat, Martin F. Mushayandebvu, and Keisuke Ushijima. "Linearized least‐squares method for interpretation of potential‐field data from sources of simple geometry." GEOPHYSICS 69, no. 3 (2004): 783–88. http://dx.doi.org/10.1190/1.1759464.

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We present a new method for interpreting isolated potential‐field (gravity and magnetic) anomaly data. A linear equation, involving a symmetric anomalous field and its horizontal gradient, is derived to provide both the depth and nature of the buried sources. In many currently available methods, either higher order derivatives or postprocessing is necessary to extract both pieces of information; therefore, data must be of very high quality. In contrast, for gravity work with our method, only a first‐order horizontal derivative is needed and the traditional data quality is sufficient. Our propo

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Widiyani, Agustina, and Azwar Sutiono. "An An Interacting Dark Energy Model with Nonminimal Derivative Coupling in the Parameterized Post-Friedmannian Framework." Indonesian Journal of Physics 33, no. 2 (2022): 1–7. http://dx.doi.org/10.5614/itb.ijp.2022.33.2.1.

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We investigation the parameterization of the cosmological model with the nonminimal derivative coupling of a scalar field where gravity is coupled nonminimally with the derivatives of dark energy components in the form of a scalar field. We follow the parameterized post-Friedmannian approach for the interacting dark energy theories. We show how the big number of free functions can be reduced by limiting certain assumptions to a few non-zero coefficients. We only consider the case that the dark sector contains at most second order in time derivatives of the metric and scalar fields. In this pap

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Zhang, Chong, Pengbo Qin, Qingtian Lü, Wenna Zhou, and Jiayong Yan. "Two New Methods Based on Implicit Expressions and Corresponding Predictor-Correctors for Gravity Anomaly Downward Continuation and Their Comparison." Remote Sensing 15, no. 10 (2023): 2698. http://dx.doi.org/10.3390/rs15102698.

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Downward continuation is a key technique for processing and interpreting gravity anomalies, as it has a major role in reducing values to horizontal planes and identifying small and shallow sources. However, it can be unstable and inaccurate, particularly when continuation depth increases. While the Milne and Adams–Bashforth methods based on numerical solutions of the mean-value theorem have partly addressed these problems, more accurate and realistic methods need to be presented to enhance results. To address these challenges, we present two new methods, Milne–Simpson and Adams–Bashforth–Moult

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GANGOPADHYAY, DEBASHIS. "GAUGE FIXING FOR LINEARIZED GRAVITY AND ANTISYMMETRIC TENSOR FIELDS." International Journal of Modern Physics A 05, no. 11 (1990): 2145–54. http://dx.doi.org/10.1142/s0217751x90000982.

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Using the functional stochastic scheme, the gauge fixing term for linearized gravity is shown to be related to longitudinal modes within the framework of the usual set of momentum projection operators. A similar analysis is done for non-Abelian antisymmetric tensor field by replacing derivatives with covariant derivatives in all relevant equations and by constructing suitable operators for projecting out transverse and longitudinal modes.

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Saibi, Hakim, Diab Bakri Hag, Mohammed Saeed Mohammed Alamri, and Hamdan Abdo Ali. "Subsurface structure investigation of the United Arab Emirates using gravity data." Open Geosciences 13, no. 1 (2021): 262–71. http://dx.doi.org/10.1515/geo-2020-0233.

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Abstract The crustal structure beneath the United Arab Emirates (UAE) is still relatively unknown. Here, we use regional gravity data to constrain the subsurface density distribution and structure of the crust of the UAE by applying diverse gravity derivatives methods such as horizontal derivative (HDR), analytic signal (AS), and tilt angle (TA) to analyze the subsurface structure and perform three-dimensional (3D) gravity inversion for imaging crustal structure from the surface down to 35 km depth. The results are compared with known geological regional structures and the location of the petr

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39

Calcagni, Gianluca. "Multifractional theories: An updated review." Modern Physics Letters A 36, no. 14 (2021): 2140006. http://dx.doi.org/10.1142/s021773232140006x.

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The status of multifractional theories is reviewed using comparative tables. Theoretical foundations, classical matter and gravity dynamics, cosmology and experimental constraints are summarized and the application of the multifractional paradigm to quantum gravity is discussed. We also clarify the issue of unitarity in theories with integer-order derivatives.

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Aschieri, Paolo. "Symmetries, Covariant Derivatives and Gravity on Noncommutative Spacetime." Progress of Theoretical Physics Supplement 171 (2007): 11–22. http://dx.doi.org/10.1143/ptps.171.11.

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Aksteiner, Steffen, Lars Andersson, Thomas Bäckdahl, Igor Khavkine, and Bernard Whiting. "Compatibility Complex for Black Hole Spacetimes." Communications in Mathematical Physics 384, no. 3 (2021): 1585–614. http://dx.doi.org/10.1007/s00220-021-04078-y.

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AbstractThe set of local gauge invariant quantities for linearized gravity on the Kerr spacetime presented by two of the authors (Aksteiner and Bäckdahl in Phys Rev Lett 121:051104, 2018) is shown to be complete. In particular, any gauge invariant quantity for linearized gravity on Kerr that is local and of finite order in derivatives can be expressed in terms of these gauge invariants and derivatives thereof. The proof is carried out by constructing a complete compatibility complex for the Killing operator, and demonstrating the equivalence of the gauge invariants from Aksteiner and Bäckdahl

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Giacchini, Breno, and Tibério Netto. "Regular Solutions in Higher-Derivative Gravity." Universe 4, no. 12 (2018): 140. http://dx.doi.org/10.3390/universe4120140.

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Local gravitational theories with more than four derivatives can have remarkable quantum properties. Namely, they can be super-renormalizable and may be unitary in the Lee-Wick sense, if the massive poles of the propagator are complex. It is important, therefore, to also explore the classical aspects of these theories. In this talk we present recent results in this direction. Specifically, we discuss the effect that that higher-order terms can have on the Newtonian potential and related singularities.

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Juliawan, Nadhie, Hyoung-Seog Chung, Jae-Woo Lee, and Sangho Kim. "Estimation and Separation of Longitudinal Dynamic Stability Derivatives with Forced Oscillation Method Using Computational Fluid Dynamics." Aerospace 8, no. 11 (2021): 354. http://dx.doi.org/10.3390/aerospace8110354.

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This paper focuses on estimating dynamic stability derivatives using a computational fluid dynamics (CFD)-based force oscillation method, and on separating the coupled dynamic derivatives terms obtained from the method. A transient RANS solver is used to calculate the time history of aerodynamic moments for a test model oscillating about the center of gravity, from which the coupled dynamic derivatives are estimated. The separation of the coupled derivatives term is carried out by simulating simple harmonic oscillation motions such as plunging motion and flapping motion which can isolate the p

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Abdelmohssin, Faisal A. Y., and Osman M. H. El Mekki. "The Hamiltonian of f(R) gravity." Canadian Journal of Physics 99, no. 9 (2021): 814–19. http://dx.doi.org/10.1139/cjp-2021-0058.

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We derive conjugate momenta variable tensors and the Hamiltonian equation of the source-free f(R) gravity from first principles using the Legendre transformation of these conjugate momenta variable tensors, conjugate coordinates variables — fundamental metric tensor and its first ordinary partial derivatives with respect to space–time coordinates and second ordinary partial derivatives with respect to space–time coordinates — and the Lagrangian of the f(R) gravity. Interpreting the derived Hamiltonian as the energy of the f(R) gravity we have shown that it vanishes for linear Lagrangians in Ri

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Islam, Safiqul, and Farook Rahaman. "A Comparison of Hořava–Lifshitz Gravity and Einstein Gravity through the Gravitational Deflection of Massive Body around Black Holes." Axioms 12, no. 4 (2023): 364. http://dx.doi.org/10.3390/axioms12040364.

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Hořava has proposed a renormalizable gravity theory with higher spatial derivatives in four dimensions. This theory may be regarded as a UV complete candidate for general relativity. After the proposal of this theory, Kehagias and Sfetsos have found a new asymptotically flat black hole solution in Hořava–Lifshitz gravity. In recent times, a new test of gravity theory is suggested that assumes the deflection of the massive body around a black hole. In this paper, we will study the effect of the Hořava–Lifshitz parameters on the black hole deflection angle and emphasize those features that permi

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Benetti, Francesco, Andrea Lapi, Giovanni Gandolfi, Balakrishna Sandeep Haridasu, and Luigi Danese. "Dark Matter in Fractional Gravity II: Tests in Galaxy Clusters." Universe 9, no. 7 (2023): 329. http://dx.doi.org/10.3390/universe9070329.

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Recently, in Benetti et al. (Astrophys. J. 2023, 949, 65), we suggested that the dark matter (DM) component in galaxies may originate fractional gravity. In such a framework, the DM component exists, but the gravitational potential associated to its density distribution is determined by a modified Poisson equation including fractional derivatives (i.e., derivatives of noninteger type), which are meant to describe nonlocal effects; as such, this scenario is different from theories where baryonic matter emulates DM-like effects via modifications of gravity (e.g., MONDian frameworks). In Benetti

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Kim, Jin Young, and Mu-In Park. "Wormholes in Einstein-Born-Infeld Gravity." EPJ Web of Conferences 168 (2018): 09003. http://dx.doi.org/10.1051/epjconf/201816809003.

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We introduce a new approach to construct wormholes without introducing exotic matters in Einstein-Born-Infeld gravity with a cosmological constant. Contary to the conventional approach, the throat is located at the place where the solutions can be joined smoothly. The metric and its derivatives are continuous so that the exotic matters are not needed there. The exoticity of the energy-momentum tensor is not essential to sustain the wormhole. We also present a method to check the stability of wormholes in the new approach.

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Ren, Yanwei, Huanhe Dong, Xinzhu Meng, and Hongwei Yang. "Research on Time-Space Fractional Model for Gravity Waves in Baroclinic Atmosphere." Mathematical Problems in Engineering 2018 (October 24, 2018): 1–14. http://dx.doi.org/10.1155/2018/1345346.

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The research of gravity solitary waves movement is of great significance to the study of ocean and atmosphere. Baroclinic atmosphere is a complex atmosphere, and it is closer to the real atmosphere. Thus, the study of gravity waves in complex atmosphere motion is becoming increasingly essential. Deriving fractional partial differential equation models to describe various waves in the atmosphere and ocean can open up a new window for us to understand the fluid movement more deeply. Generally, the time fractional equations are obtained to reflect the nonlinear waves and few space-time fractional

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Fonseca, Ijar M., and Peter M. Bainum. "Integrated Structural and Control Optimization." Journal of Vibration and Control 10, no. 10 (2004): 1377–91. http://dx.doi.org/10.1177/1077546304042043.

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This paper focuses on the integrated structural/control optimization of a large space structure with a robot arm subject to the gravity-gradient torque through a semi-analytical approach. It is well known that the computer effort to compute numerically derivatives of the constraints with respect to design variables makes the process expensive and time-consuming. In this sense, a semi-analytical approach may represent a good alternative when optimizing systems that require sensitivity calculations with respect to design parameters. In this study, constraints from the structure and control disci

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Juárez-Aubry, Benito A., Bernard S. Kay, Tonatiuh Miramontes, and Daniel Sudarsky. "The Hadamard condition on a Cauchy surface and the renormalized stress-energy tensor." Journal of Cosmology and Astroparticle Physics 2024, no. 10 (2024): 002. http://dx.doi.org/10.1088/1475-7516/2024/10/002.

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Abstract Given a Cauchy surface in a curved spacetime and a suitably defined quantum state on the CCR algebra of the Klein-Gordon quantum field on that surface, we show, by expanding the squared spacetime geodesic distance and the 'U' and 'V' Hadamard coefficients (and suitable derivatives thereof) in sufficiently accurate covariant Taylor expansions on the surface that the renormalized expectation value of the quantum stress-energy tensor on the surface is determined by the geometry of the surface and the first 4 time derivatives of the metric off the surface, in addition to the Cauchy data f

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