Using full potential density functional theory calculations we have investigated the structural a... more Using full potential density functional theory calculations we have investigated the structural and electronic properties of graphene and some other graphene-like materials, viz., monolayer of SiC, GeC, BN, AlN, GaN, ZnO, ZnS and ZnSe. We hope, with the advancement of material synthesis techniques, some these new materials will be synthesized in the near future for potential applications in various nano-devices.
Using full-potential density functional theory (DFT) calculations, we found a small asymmetry in ... more Using full-potential density functional theory (DFT) calculations, we found a small asymmetry in the Fermi velocity of electrons and holes in graphene. These Fermi velocity values and their average were found to decrease with increasing in-plane homogeneous biaxial strain; the variation in Fermi velocity is quadratic in strain. The results, which can be verified by Landau level spectroscopy and quantum capacitance measurements of bi-axially strained graphene, promise potential applications in graphene based straintronics and flexible electronics.
Based on classical electrodynamics, it is argued that the Coulomb potential (which is strictly va... more Based on classical electrodynamics, it is argued that the Coulomb potential (which is strictly valid for two point charges at rest), commonly used in the study of energy levels of hydrogen atom is not the correct one, because the electron in the hydrogen atom moves with relativistic speeds with respect to the nucleus. Retardation effect has to be considered in accordance with Liénard-Wiechert (or retarded) potential of a moving charge or the relativistic electrodynamics. However, such a consideration introduces a correction to the Coulomb potential, whose quantum mechanical expectation value is estimated at E ret = − mc 2 α 4 2n 3 (l+1/2) , which is of the same order as the fine structure of hydrogen atom and hence added to the standard energy eigenvalue values of H-atom. This correction lifts the l-degeneracy in the spectra of H-atom and hence modifies the standard result. The result disturbs the existing agreement between the theory and experiments on H-atom and hence requires further theoretical and experimental re-examination. The implications of this result for the Kepler-problem in general is also discussed in the context of Heaviside's gravity, which seems to offer an alternative explanation for the non-Newtonian perihelion advance of Mercury without invoking the space-time curvature formalism of Einstein's general theory of relativity.
The invariance of the speed of light in all inertial frames − the second postulate of special the... more The invariance of the speed of light in all inertial frames − the second postulate of special theory of relativity (STR) − is shown to be an inevitable consequence of the relativity principle of special theory of relativity taken in conjunction with the homogeneity of space and time in all inertial fames, i.e., the 1st postulate of STR. The new• approach presented here renders the learning of special theory of relativity logically simpler, as it makes use of only one postulate.
Using full-potential density functional calculations we have investigated the structural and elec... more Using full-potential density functional calculations we have investigated the structural and electronic properties of graphene and some of its structural analogues, viz., monolayer (ML) of SiC, GeC, BN, AlN, GaN, ZnO, ZnS and ZnSe. While our calculations corroborate some of the reported results based on different methods, our results on ZnSe, the two dimensional bulk modulus of ML-GeC, ML-AlN, ML-GaN, ML-ZnO and ML-ZnS and the effective masses of the charge carriers in these binary mono-layers are something new. With the current progress in synthesis techniques, some of these new materials may be synthesized in near future for applications in nano-devices.
Using full-potential density functional calculations we have investigated the structural and elec... more Using full-potential density functional calculations we have investigated the structural and electronic properties of graphene and some of its structural analogues, viz., monolayer (ML) of SiC, GeC, BN, AlN, GaN, ZnO, ZnS and ZnSe. While our calculations corroborate some of the reported results based on different methods, our results on ZnSe, the two dimensional bulk modulus of ML-GeC, ML-AlN, ML-GaN, ML-ZnO and ML-ZnS and the effective masses of the charge carriers in these binary mono-layers are something new. With the current progress in synthesis techniques, some of these new materials may be synthesized in near future for applications in nano-devices.
We present ab initio calculations on the effect of in-plane equi-biaxial strain on the structural... more We present ab initio calculations on the effect of in-plane equi-biaxial strain on the structural and electronic properties of hypothetical graphene-like GaN monolayer (ML-GaN). It was found that ML-GaN got buckled for compressive strain in excess of 7.281 %; buckling parameter increased quadratic-ally with compressive strain. The 2D bulk modulus of ML-GaN was found to be smaller than that of graphene and graphene-like ML-BN, which reflects weaker bond in ML-GaN. More importantly, the band gap and effective masses of charge carriers in ML-GaN were found to be tunable by application of in-plane equi-biaxial strain. In particular, when compressive biaxial strain of about 3 % was reached, a transition from indirect to direct band gap-phase occurred with significant change in the value and nature of effective masses of charge carriers; buckling and tensile strain reduced the band gap - the band gap reduced to 50 % of its unstrained value at 6.36 % tensile strain and to 0 eV at an extrap...
The effect of general relativistic prediction of the dependence of mass on gravitational potentia... more The effect of general relativistic prediction of the dependence of mass on gravitational potential on the dynamics of a planet moving around the sun is shown to have a negative contribution of 14.326 arcsec/century towards the overall non-Newtonian perihelion advance of Mercury.
We present ab initio calculations which show that the direct-band-gap, effective masses and Fermi... more We present ab initio calculations which show that the direct-band-gap, effective masses and Fermi velocities of charge carriers in ZnO monolayer (ML-ZnO) in graphene-like honeycomb structure are all tunable by application of in-plane homogeneous biaxial strain. Within our simulated strain limit of ± 10 strain. Moreover, the average Fermi velocity of electrons in unstrained ML-ZnO is of the same order of magnitude as that in graphene. The results promise potential applications of ML-ZnO in mechatronics/straintronics and other nanodevices such as the nano-electromechanical systems (NEMS) and nano-optomechanical systems (NOMS).
The study of graphene, since its discovery around 2004, is possibly the largest and fastest growi... more The study of graphene, since its discovery around 2004, is possibly the largest and fastest growing field of research in material science, because of its exotic mechanical, thermal, electronic, optical and chemical properties. The studies of graphene have also led to further research in exploring the field of two dimensional (2D) systems in general. For instance, a number of other 2D crystals (not based on carbon, e.g., boronitrene, silicone, graphane, etc.) have been synthesized or predicted theoretically in recent years. Further, theoretical studies have predicted the possibility of other 2D hexagonal crystals of Ge, SiC, GeC, AlN, GaN, etc. The properties of these 2D materials are very different from their bulk. We shall present the general exotic properties of graphene like 2D systems followed by our computational results on the structural and electronic properties of some of them.
Using full potential density functional calculations within local density approximation (LDA), we... more Using full potential density functional calculations within local density approximation (LDA), we report our investigation of the structural electronic properties of silicene (the graphene analogue of silicon), the strips of which has been synthesized recently on Ag(110) and Ag(100) surfaces. An assumed planar and an optimized buckled two dimensional (2D) hexagonal structures have been considered for comparisons of their electronic properties. Planar silicene shows a gapless band structure analogous to the band structure of graphene with charge carriers behaving like mass-less Dirac fermions, while the structurally optimized buckled silicene shows a small direct energy band gap of about 25 meV (at the K point of the hexagonal Brillouin zone) in its electronic structure and the charge carriers in this case behave like massive Dirac fermions. The actual band gap would be larger than this as LDA is known to underestimate the gap. The average Fermi velocity of the Dirac fermions in sili...
Using full-potential density functional calculations within local density approximation (LDA), we... more Using full-potential density functional calculations within local density approximation (LDA), we found mechanically tunable band-gap in ZnO monolayer (ML-ZnO) in graphene-like honeycomb structure, by simulated application of in-plane homogeneous biaxial strain. Unstrained ML-ZnO was found to have a direct band gap of energy 1.68 eV within LDA; the actual band gap would be more, since LDA is known to underestimate the gap. Within our simulated strain limit of about plus or minus 10%, the band gap remains direct and shows a strong non-linear variation with strain. The results may find applications in future nano-electromechanical systems (NEMS) and nano-optomechanial systems (NOMS).
The invariance of the speed of light in all inertial frames is shown to be an inevitable conseque... more The invariance of the speed of light in all inertial frames is shown to be an inevitable consequence of the relativity principle of special relativity contrary to the view held by Hsu and Hsu in taiji relativity where the speed of light is no longer a universal constant.The present approach is not only new but also much simpler than the existing approaches. 1 The two postulates of special relativity, viz.,(i) the relativity principle and (ii) the postulate on the speed of light, are the basics of a theory that has been tremendously successful in describing a wide range of phenomena, although there exist derivations of Lorentz transformations (LT) without the postulate on the speed of light [1-8]. However, using the relativity principle only, Hsu and Hsu [9] have developed a general theory, named taiji relativity, which has four dimensional symmetry and is consistent with experiments although the speed of light is no longer a universal constant within its framework. In the developmen...
Adopting Schwinger's formalism for inferring Maxwell-Lorentz equations (MLEs) and combining t... more Adopting Schwinger's formalism for inferring Maxwell-Lorentz equations (MLEs) and combining three ingredients: (i) the laws of gravitostatics, (ii) the Galileo-Newton principle of relativity and (iii) existence of gravitational waves which travel in vacuum with a finite speed $c_g$, we inferred two sets of gravito-Maxwell-Lorentz Equations (g-MLEs). One of these sets corresponds to Heaviside's Gravity of 1893 and the other set corresponds to what we call Maxwellian Gravity (MG). HG and MG are mere two mathematical representations of a single physical theory called Heaviside-Maxwellian Gravity (HMG). While rediscovering Heaviside's gravitational field equations following Schwinger's formalism, we found a correction to Heaviside's speculative gravito-Lorentz force law. This work presents a Galilo-Newtonian foundation of gravitomagnetic effects and gravitational waves, caused by time-varying sources and fields, which are currently considered outside the domain of Ne...
The Gravity Probe B (GP-B) Experiment of NASA was aimed to test the theoretical predictions of Ei... more The Gravity Probe B (GP-B) Experiment of NASA was aimed to test the theoretical predictions of Einstein's 1916 relativistic tensor theory of gravity in curved space-time (General Relativity (GR)) concerning the spin axis precession of a gyroscope moving in the field of a slowly rotating massive body, like the Earth. In 2011, GP-B mission reported its measured data on the precession (displacement) angles of the spin axes of the four spherical gyroscopes housed in a satellite orbiting 642 km (400 mi) above the Earth in polar orbit. The reported results are in agreement with the predictions of GR. For the first time, here we report an undergraduate level explanation of the GP-B experimental results using Heaviside-Maxwellian (vector) Gravity (HMG) in flat space-time, first formulated by Heaviside in 1893, and later considered/re-discovered by many authors. Our new explanation of the GP-B results provides a new test of HMG apart from the existing ones, which deserves the attention o...
We show that if we start with the free Dirac Lagrangian, and demand local phase invariance, consi... more We show that if we start with the free Dirac Lagrangian, and demand local phase invariance, considering the total phase coming from two independent contributions associated with the charge and mass degrees of freedom of charged Dirac particles, then we are forced to introduce two massless independent vector fields for charged Dirac particles that generate all of electrodynamics and gravitodynamics of Heaviside's Gravity of 1893 or Maxwellian Gravity and specify the charge and mass currents produced by charged Dirac particles. From this approach we found (i) a new mathematical representation of Lorentz-Maxwell's equations of electrodynamics physically equivalent to the standard equations and (ii) two equivalent sets of gravito-Lorentz-Maxwell's equations of vector gravity by correcting Heaviside's speculative gravito-Lorentz force. The gravito-Lorentz-Maxwell equations obtained here match with several classical (Galilean or Special or General Relativistic) versions of...
Adopting two independent approaches (a) Lorentz-invariance of physical laws and (b) local phase i... more Adopting two independent approaches (a) Lorentz-invariance of physical laws and (b) local phase invariance of quantum field theory applied to the Dirac Lagrangian for massive electrically neutral Dirac particles, we rediscovered the fundamental field equations of Heaviside Gravity (HG) of 1893 and Maxwellian Gravity (MG), which look different from each other due to a sign difference in some terms of their respective field equations. However, they are shown to represent two mathematical representations of a single physical theory of vector gravity that we name here as Heaviside-Maxwellian Gravity (HMG), in which the speed of gravitational waves in vacuum is uniquely found to be equal to the speed of light in vacuum. We also corrected a sign error in Heaviside's speculative gravitational analogue of the Lorentz force law. This spin-1 HMG is shown to produce attractive force between like masses under static condition, contrary to the prevalent view of field theorists. Galileo's...
We present ab initio density functional theory (DFT) calculations on the effect of in-plane equi-... more We present ab initio density functional theory (DFT) calculations on the effect of in-plane equi-biaxial strain on the structural and electronic properties of graphene-like GaN monolayer (ML-GaN). For compressive strain in excess of 7.2%, ML-GaN gets buckled; buckling parameter increases quadratically with compressive strain. The 2D bulk modulus of ML-GaN was found to be smaller than that of graphene and graphene-like ML-BN, which reflects weaker bond in ML-GaN. More importantly, the bandgap and effective masses of charge carriers in ML-GaN were found to be tunable by application of in-plane equi-biaxial strain. In particular, when compressive biaxial strain of about 3% was reached, a transition from indirect to direct bandgap-phase occurred with change in the value and nature of effective masses of charge carriers; buckling and tensile strain reduced the bandgap — the bandgap reduced to 50% of its unstrained value at 6.36% tensile strain and to 0 eV at an extrapolated tensile strai...
gravitoelectromagnetic equations of Ummarino and Gallerati (UG) in their linearized version of ge... more gravitoelectromagnetic equations of Ummarino and Gallerati (UG) in their linearized version of general relativity (GR) are shown to match with (a) our previously reported special relativistic Maxwellian Gravity equations in the non-relativistic limit and with (b) the non-relativistic equations derived here, when the speed of gravity c g (an undetermined parameter of the theory here) is set equal to c (the speed of light in vacuum). Seen in the light of our new results, the UG equations satisfy the Correspondence Principle (cp), while many other versions of linearized GR equations that are being (or may be) used to interpret the experimental data defy the cp. Such new findings assume significance and relevance in the contexts of recent detection of gravitational waves and the gravitomagnetic field of the spinning earth and their interpretations. Being well-founded and self-consistent, the equations may be of interest and useful to researchers exploring the phenomenology of gravitomagnetism, gravitational waves and the novel interplay of gravity with different states of matter in flat space-time like UG's interesting work on superconductors in weak gravitational fields.
The invariance of the speed of light in all inertial frames − the second postulate of special the... more The invariance of the speed of light in all inertial frames − the second postulate of special theory of relativity (STR) − is shown to be an inevitable consequence of the relativity principle of special theory of relativity taken in conjunction with the homogeneity of space and time in all inertial fames, i.e., the 1st postulate of STR. The new• approach presented here renders the learning of special theory of relativity logically simpler, as it makes use of only one postulate.
Using full potential density functional theory calculations we have investigated the structural a... more Using full potential density functional theory calculations we have investigated the structural and electronic properties of graphene and some other graphene-like materials, viz., monolayer of SiC, GeC, BN, AlN, GaN, ZnO, ZnS and ZnSe. We hope, with the advancement of material synthesis techniques, some these new materials will be synthesized in the near future for potential applications in various nano-devices.
Using full-potential density functional theory (DFT) calculations, we found a small asymmetry in ... more Using full-potential density functional theory (DFT) calculations, we found a small asymmetry in the Fermi velocity of electrons and holes in graphene. These Fermi velocity values and their average were found to decrease with increasing in-plane homogeneous biaxial strain; the variation in Fermi velocity is quadratic in strain. The results, which can be verified by Landau level spectroscopy and quantum capacitance measurements of bi-axially strained graphene, promise potential applications in graphene based straintronics and flexible electronics.
Based on classical electrodynamics, it is argued that the Coulomb potential (which is strictly va... more Based on classical electrodynamics, it is argued that the Coulomb potential (which is strictly valid for two point charges at rest), commonly used in the study of energy levels of hydrogen atom is not the correct one, because the electron in the hydrogen atom moves with relativistic speeds with respect to the nucleus. Retardation effect has to be considered in accordance with Liénard-Wiechert (or retarded) potential of a moving charge or the relativistic electrodynamics. However, such a consideration introduces a correction to the Coulomb potential, whose quantum mechanical expectation value is estimated at E ret = − mc 2 α 4 2n 3 (l+1/2) , which is of the same order as the fine structure of hydrogen atom and hence added to the standard energy eigenvalue values of H-atom. This correction lifts the l-degeneracy in the spectra of H-atom and hence modifies the standard result. The result disturbs the existing agreement between the theory and experiments on H-atom and hence requires further theoretical and experimental re-examination. The implications of this result for the Kepler-problem in general is also discussed in the context of Heaviside's gravity, which seems to offer an alternative explanation for the non-Newtonian perihelion advance of Mercury without invoking the space-time curvature formalism of Einstein's general theory of relativity.
The invariance of the speed of light in all inertial frames − the second postulate of special the... more The invariance of the speed of light in all inertial frames − the second postulate of special theory of relativity (STR) − is shown to be an inevitable consequence of the relativity principle of special theory of relativity taken in conjunction with the homogeneity of space and time in all inertial fames, i.e., the 1st postulate of STR. The new• approach presented here renders the learning of special theory of relativity logically simpler, as it makes use of only one postulate.
Using full-potential density functional calculations we have investigated the structural and elec... more Using full-potential density functional calculations we have investigated the structural and electronic properties of graphene and some of its structural analogues, viz., monolayer (ML) of SiC, GeC, BN, AlN, GaN, ZnO, ZnS and ZnSe. While our calculations corroborate some of the reported results based on different methods, our results on ZnSe, the two dimensional bulk modulus of ML-GeC, ML-AlN, ML-GaN, ML-ZnO and ML-ZnS and the effective masses of the charge carriers in these binary mono-layers are something new. With the current progress in synthesis techniques, some of these new materials may be synthesized in near future for applications in nano-devices.
Using full-potential density functional calculations we have investigated the structural and elec... more Using full-potential density functional calculations we have investigated the structural and electronic properties of graphene and some of its structural analogues, viz., monolayer (ML) of SiC, GeC, BN, AlN, GaN, ZnO, ZnS and ZnSe. While our calculations corroborate some of the reported results based on different methods, our results on ZnSe, the two dimensional bulk modulus of ML-GeC, ML-AlN, ML-GaN, ML-ZnO and ML-ZnS and the effective masses of the charge carriers in these binary mono-layers are something new. With the current progress in synthesis techniques, some of these new materials may be synthesized in near future for applications in nano-devices.
We present ab initio calculations on the effect of in-plane equi-biaxial strain on the structural... more We present ab initio calculations on the effect of in-plane equi-biaxial strain on the structural and electronic properties of hypothetical graphene-like GaN monolayer (ML-GaN). It was found that ML-GaN got buckled for compressive strain in excess of 7.281 %; buckling parameter increased quadratic-ally with compressive strain. The 2D bulk modulus of ML-GaN was found to be smaller than that of graphene and graphene-like ML-BN, which reflects weaker bond in ML-GaN. More importantly, the band gap and effective masses of charge carriers in ML-GaN were found to be tunable by application of in-plane equi-biaxial strain. In particular, when compressive biaxial strain of about 3 % was reached, a transition from indirect to direct band gap-phase occurred with significant change in the value and nature of effective masses of charge carriers; buckling and tensile strain reduced the band gap - the band gap reduced to 50 % of its unstrained value at 6.36 % tensile strain and to 0 eV at an extrap...
The effect of general relativistic prediction of the dependence of mass on gravitational potentia... more The effect of general relativistic prediction of the dependence of mass on gravitational potential on the dynamics of a planet moving around the sun is shown to have a negative contribution of 14.326 arcsec/century towards the overall non-Newtonian perihelion advance of Mercury.
We present ab initio calculations which show that the direct-band-gap, effective masses and Fermi... more We present ab initio calculations which show that the direct-band-gap, effective masses and Fermi velocities of charge carriers in ZnO monolayer (ML-ZnO) in graphene-like honeycomb structure are all tunable by application of in-plane homogeneous biaxial strain. Within our simulated strain limit of ± 10 strain. Moreover, the average Fermi velocity of electrons in unstrained ML-ZnO is of the same order of magnitude as that in graphene. The results promise potential applications of ML-ZnO in mechatronics/straintronics and other nanodevices such as the nano-electromechanical systems (NEMS) and nano-optomechanical systems (NOMS).
The study of graphene, since its discovery around 2004, is possibly the largest and fastest growi... more The study of graphene, since its discovery around 2004, is possibly the largest and fastest growing field of research in material science, because of its exotic mechanical, thermal, electronic, optical and chemical properties. The studies of graphene have also led to further research in exploring the field of two dimensional (2D) systems in general. For instance, a number of other 2D crystals (not based on carbon, e.g., boronitrene, silicone, graphane, etc.) have been synthesized or predicted theoretically in recent years. Further, theoretical studies have predicted the possibility of other 2D hexagonal crystals of Ge, SiC, GeC, AlN, GaN, etc. The properties of these 2D materials are very different from their bulk. We shall present the general exotic properties of graphene like 2D systems followed by our computational results on the structural and electronic properties of some of them.
Using full potential density functional calculations within local density approximation (LDA), we... more Using full potential density functional calculations within local density approximation (LDA), we report our investigation of the structural electronic properties of silicene (the graphene analogue of silicon), the strips of which has been synthesized recently on Ag(110) and Ag(100) surfaces. An assumed planar and an optimized buckled two dimensional (2D) hexagonal structures have been considered for comparisons of their electronic properties. Planar silicene shows a gapless band structure analogous to the band structure of graphene with charge carriers behaving like mass-less Dirac fermions, while the structurally optimized buckled silicene shows a small direct energy band gap of about 25 meV (at the K point of the hexagonal Brillouin zone) in its electronic structure and the charge carriers in this case behave like massive Dirac fermions. The actual band gap would be larger than this as LDA is known to underestimate the gap. The average Fermi velocity of the Dirac fermions in sili...
Using full-potential density functional calculations within local density approximation (LDA), we... more Using full-potential density functional calculations within local density approximation (LDA), we found mechanically tunable band-gap in ZnO monolayer (ML-ZnO) in graphene-like honeycomb structure, by simulated application of in-plane homogeneous biaxial strain. Unstrained ML-ZnO was found to have a direct band gap of energy 1.68 eV within LDA; the actual band gap would be more, since LDA is known to underestimate the gap. Within our simulated strain limit of about plus or minus 10%, the band gap remains direct and shows a strong non-linear variation with strain. The results may find applications in future nano-electromechanical systems (NEMS) and nano-optomechanial systems (NOMS).
The invariance of the speed of light in all inertial frames is shown to be an inevitable conseque... more The invariance of the speed of light in all inertial frames is shown to be an inevitable consequence of the relativity principle of special relativity contrary to the view held by Hsu and Hsu in taiji relativity where the speed of light is no longer a universal constant.The present approach is not only new but also much simpler than the existing approaches. 1 The two postulates of special relativity, viz.,(i) the relativity principle and (ii) the postulate on the speed of light, are the basics of a theory that has been tremendously successful in describing a wide range of phenomena, although there exist derivations of Lorentz transformations (LT) without the postulate on the speed of light [1-8]. However, using the relativity principle only, Hsu and Hsu [9] have developed a general theory, named taiji relativity, which has four dimensional symmetry and is consistent with experiments although the speed of light is no longer a universal constant within its framework. In the developmen...
Adopting Schwinger's formalism for inferring Maxwell-Lorentz equations (MLEs) and combining t... more Adopting Schwinger's formalism for inferring Maxwell-Lorentz equations (MLEs) and combining three ingredients: (i) the laws of gravitostatics, (ii) the Galileo-Newton principle of relativity and (iii) existence of gravitational waves which travel in vacuum with a finite speed $c_g$, we inferred two sets of gravito-Maxwell-Lorentz Equations (g-MLEs). One of these sets corresponds to Heaviside's Gravity of 1893 and the other set corresponds to what we call Maxwellian Gravity (MG). HG and MG are mere two mathematical representations of a single physical theory called Heaviside-Maxwellian Gravity (HMG). While rediscovering Heaviside's gravitational field equations following Schwinger's formalism, we found a correction to Heaviside's speculative gravito-Lorentz force law. This work presents a Galilo-Newtonian foundation of gravitomagnetic effects and gravitational waves, caused by time-varying sources and fields, which are currently considered outside the domain of Ne...
The Gravity Probe B (GP-B) Experiment of NASA was aimed to test the theoretical predictions of Ei... more The Gravity Probe B (GP-B) Experiment of NASA was aimed to test the theoretical predictions of Einstein's 1916 relativistic tensor theory of gravity in curved space-time (General Relativity (GR)) concerning the spin axis precession of a gyroscope moving in the field of a slowly rotating massive body, like the Earth. In 2011, GP-B mission reported its measured data on the precession (displacement) angles of the spin axes of the four spherical gyroscopes housed in a satellite orbiting 642 km (400 mi) above the Earth in polar orbit. The reported results are in agreement with the predictions of GR. For the first time, here we report an undergraduate level explanation of the GP-B experimental results using Heaviside-Maxwellian (vector) Gravity (HMG) in flat space-time, first formulated by Heaviside in 1893, and later considered/re-discovered by many authors. Our new explanation of the GP-B results provides a new test of HMG apart from the existing ones, which deserves the attention o...
We show that if we start with the free Dirac Lagrangian, and demand local phase invariance, consi... more We show that if we start with the free Dirac Lagrangian, and demand local phase invariance, considering the total phase coming from two independent contributions associated with the charge and mass degrees of freedom of charged Dirac particles, then we are forced to introduce two massless independent vector fields for charged Dirac particles that generate all of electrodynamics and gravitodynamics of Heaviside's Gravity of 1893 or Maxwellian Gravity and specify the charge and mass currents produced by charged Dirac particles. From this approach we found (i) a new mathematical representation of Lorentz-Maxwell's equations of electrodynamics physically equivalent to the standard equations and (ii) two equivalent sets of gravito-Lorentz-Maxwell's equations of vector gravity by correcting Heaviside's speculative gravito-Lorentz force. The gravito-Lorentz-Maxwell equations obtained here match with several classical (Galilean or Special or General Relativistic) versions of...
Adopting two independent approaches (a) Lorentz-invariance of physical laws and (b) local phase i... more Adopting two independent approaches (a) Lorentz-invariance of physical laws and (b) local phase invariance of quantum field theory applied to the Dirac Lagrangian for massive electrically neutral Dirac particles, we rediscovered the fundamental field equations of Heaviside Gravity (HG) of 1893 and Maxwellian Gravity (MG), which look different from each other due to a sign difference in some terms of their respective field equations. However, they are shown to represent two mathematical representations of a single physical theory of vector gravity that we name here as Heaviside-Maxwellian Gravity (HMG), in which the speed of gravitational waves in vacuum is uniquely found to be equal to the speed of light in vacuum. We also corrected a sign error in Heaviside's speculative gravitational analogue of the Lorentz force law. This spin-1 HMG is shown to produce attractive force between like masses under static condition, contrary to the prevalent view of field theorists. Galileo's...
We present ab initio density functional theory (DFT) calculations on the effect of in-plane equi-... more We present ab initio density functional theory (DFT) calculations on the effect of in-plane equi-biaxial strain on the structural and electronic properties of graphene-like GaN monolayer (ML-GaN). For compressive strain in excess of 7.2%, ML-GaN gets buckled; buckling parameter increases quadratically with compressive strain. The 2D bulk modulus of ML-GaN was found to be smaller than that of graphene and graphene-like ML-BN, which reflects weaker bond in ML-GaN. More importantly, the bandgap and effective masses of charge carriers in ML-GaN were found to be tunable by application of in-plane equi-biaxial strain. In particular, when compressive biaxial strain of about 3% was reached, a transition from indirect to direct bandgap-phase occurred with change in the value and nature of effective masses of charge carriers; buckling and tensile strain reduced the bandgap — the bandgap reduced to 50% of its unstrained value at 6.36% tensile strain and to 0 eV at an extrapolated tensile strai...
gravitoelectromagnetic equations of Ummarino and Gallerati (UG) in their linearized version of ge... more gravitoelectromagnetic equations of Ummarino and Gallerati (UG) in their linearized version of general relativity (GR) are shown to match with (a) our previously reported special relativistic Maxwellian Gravity equations in the non-relativistic limit and with (b) the non-relativistic equations derived here, when the speed of gravity c g (an undetermined parameter of the theory here) is set equal to c (the speed of light in vacuum). Seen in the light of our new results, the UG equations satisfy the Correspondence Principle (cp), while many other versions of linearized GR equations that are being (or may be) used to interpret the experimental data defy the cp. Such new findings assume significance and relevance in the contexts of recent detection of gravitational waves and the gravitomagnetic field of the spinning earth and their interpretations. Being well-founded and self-consistent, the equations may be of interest and useful to researchers exploring the phenomenology of gravitomagnetism, gravitational waves and the novel interplay of gravity with different states of matter in flat space-time like UG's interesting work on superconductors in weak gravitational fields.
The invariance of the speed of light in all inertial frames − the second postulate of special the... more The invariance of the speed of light in all inertial frames − the second postulate of special theory of relativity (STR) − is shown to be an inevitable consequence of the relativity principle of special theory of relativity taken in conjunction with the homogeneity of space and time in all inertial fames, i.e., the 1st postulate of STR. The new• approach presented here renders the learning of special theory of relativity logically simpler, as it makes use of only one postulate.
Recently reported [Eur. Phys. J. C., 77, 549 (2017)] gravitoelectromagnetic equations of Ummarino... more Recently reported [Eur. Phys. J. C., 77, 549 (2017)] gravitoelectromagnetic equations of Ummarino and Gallerati (UG) in their linearized version of General Relativity (GR) are shown to match with (a) our previously reported special relativistic Maxwellian Gravity equations in the non-relativistic limit and with (b) the non-relativistic equations derived here, when the speed of gravity c g (an undetermined parameter of the theory here) is set equal to c (the speed of light in vacuum). Seen in the light of our new results, the UG equations satisfy the Correspondence Principle (CP), while many other versions of linearized GR equations that are being (or may be) used to interpret the experimental data defy the CP. Such new findings assume significance and relevance in the contexts of recent detection of gravita-tional waves and the gravitomagnetic field of the spinning earth and their interpretations. Being well-founded and self-consistent, the equations may be of interest and useful to researchers exploring the phenomenology of gravitomagnetism, gravitational waves and the novel interplay of gravity with different states of matter in flat space-time like UG's interesting work on supercon-ductors in weak gravitational fields.
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Papers by Harihar Behera