Supermassive DEOs (SMDEOs) are cosmologically evolved objects made of irreducible incompressible supranuclear dense superfluids: The state we consider to govern the matter inside the cores of massive neutron stars. Th...Supermassive DEOs (SMDEOs) are cosmologically evolved objects made of irreducible incompressible supranuclear dense superfluids: The state we consider to govern the matter inside the cores of massive neutron stars. These cores are practically trapped in false vacua, rendering their detection by outside observers impossible. Based on massive parallel computations and theoretical investigations, we show that SMDEOs at the centres of spiral galaxies that are surrounded by massive rotating torii of normal matter may serve as powerful sources for gravitational waves carrying away roughly 1042 erg/s. Due to the extensive cooling by GWs, the SMDEO-Torus systems undergo glitching, through which both rotational and gravitational energies are abruptly ejected into the ambient media, during which the topologies of the embedding spacetimes change from curved into flatter ones, thereby triggering a burst gravitational energy of order 1059 erg. Also, the effects of glitches found to alter the force balance of objects in the Lagrangian-L1 region between the central SMDEO-Torus system and the bulge, enforcing the enclosed objects to develop violent motions, that may explain the origin of the rotational curve irregularities observed in the innermost part of spiral galaxies. Our study shows that the generated GWs at the centres of galaxies, which traverse billions of objects during their outward propagations throughout the entire galaxy, lose energy due to repeatedly squeezing and stretching the objects. Here, we find that these interactions may serve as damping processes that give rise to the formation of collective forces f∝m(r)/r, that point outward, endowing the objects with the observed flat rotation curves. Our approach predicts a correlation between the baryonic mass and the rotation velocities in galaxies, which is in line with the Tully-Fisher relation. The here-presented self-consistent approach explains nicely the observed rotation curves without invoking dark matter or modifying Newtonian gravitation in the low-field approximation.展开更多
There is a significant difference between the calculation based on the theory of general relativity and observation of rotation curves of spiral galaxies. To describe this discrepancy, two distinct theories have been ...There is a significant difference between the calculation based on the theory of general relativity and observation of rotation curves of spiral galaxies. To describe this discrepancy, two distinct theories have been proposed so far： existence of dark matter and modification of underlying gravitational theory. In the absence of dark matter, it is assumed that the theory of general relativity on galactic scales needs to be modified. This letter is devoted to explaining this difference in a modified teleparMIeI gravity. We show that modified teleparallel gravity favors flatness of rotation curves of spiral galaxies much in the same way as observation shows.展开更多
Warm dark matter has, by definition, a velocity dispersion. Let v<sub>hms</sub>(a)=v<sub>hms</sub><sub></sub>(1)/a be the root-mean-square velocity of non-relativistic warm dark mat...Warm dark matter has, by definition, a velocity dispersion. Let v<sub>hms</sub>(a)=v<sub>hms</sub><sub></sub>(1)/a be the root-mean-square velocity of non-relativistic warm dark matter particles in the early universe at expansion parameter a. v<sub>hms</sub><sub></sub>(1) is an adiabatic invariant. We obtain v<sub>hms</sub><sub></sub>(1) in the core of 11 dwarf galaxies dominated by dark matter, from their observed rotation curves, up to a rotation and relaxation correction. We obtain a mean 0.490 km/s and standard deviation 0.160 km/s, with a distribution peaked at the lower end. We apply a mild, data driven, rotation and relaxation correction that obtains the adiabatic invariant in the core of the galaxies: v<sub>hms</sub></sub>(1)=0.406 ±0.069 km/s. These two small relative standard deviations justify the prediction that the adiabatic invariant v<sub>hms</sub><sub></sub>(1) in the core of the galaxies is of cosmological origin if dark matter is warm. This result is in agreement with measurements of v<sub>hms</sub></sub>(1) based on spiral galaxy rotation curves, galaxy ultra-violet luminosity distributions, galaxy stellar mass distributions, the formation of first galaxies, reionization, and the velocity dispersion cut-off mass.展开更多
The pictures from the James Webb Space Telescope (JWST) suggest that massive galaxies were already at the beginning of the expansion of the Universe because there was too short time to create them. It is consistent wi...The pictures from the James Webb Space Telescope (JWST) suggest that massive galaxies were already at the beginning of the expansion of the Universe because there was too short time to create them. It is consistent with the new cosmology presented within the Scale-Symmetric Theory (SST). The phase transitions of the initial inflation field described in SST lead to the Protoworld—its core was built of dark matter (DM). We show that the DAMA/LIBRA annual-modulation amplitude forced by the change of the Earth’s velocity (i.e. baryonic-matter (BM) velocity) in relation to the spinning DM field in our Galaxy’s halo should be very low. We calculated that in the DM-BM weak interactions are created single and entangled spacetime condensates with a lowest mass/energy of 0.807 keV—as the Higgs boson they can decay to two photons, so we can indirectly detect DM. Our results are consistent with the averaged DAMA/LIBRA/COSINE-100 curve describing the dependence of the event rate on the photon energy in single-hit events. We calculated the mean dark-matter-halo (DMH) mass around quasars, we also described the origin of the plateaux in the rotation curves for the massive spiral galaxies, the role of DM-loops in magnetars, the origin of CMB, the AGN-jet and galactic-halo production, and properties of dark energy (DE).展开更多
The radical hypothesis concerning the physics of gravitational black-body radiation is placed on a more solid statistical mechanics foundation in this study. As the concepts and formalism in the former presentation ar...The radical hypothesis concerning the physics of gravitational black-body radiation is placed on a more solid statistical mechanics foundation in this study. As the concepts and formalism in the former presentation are only partially developed and furthermore, suffer from an unfortunate misstep regarding Hawking radiation and the hypothetical gravitational black-body temperature of a parcel or distribution of energy;this paper aims to fill in some of the theoretical gaps in the derivation of the Planck radiation formula for gravity (or non-Euclidean space-time), and there by provide a more complete and transparent quantum theory of thermal gravitational radiation.展开更多
Understanding the dark matter distribution throughout a galaxy can provide insight into its elusive nature. Numerous density profiles, such as the Navarro, Frenk and White model, have been created in an attempt to stu...Understanding the dark matter distribution throughout a galaxy can provide insight into its elusive nature. Numerous density profiles, such as the Navarro, Frenk and White model, have been created in an attempt to study this distribution through analyzing orbital velocities of luminous matter and modeling dark matter distributions to explain these observations. However, we are interested in a simple model to consider the significant fluctuations in rotation curves at larger radii. Therefore, our model is much simpler compared to those previously mentioned. Our model used all the observational data available for four selected galactic rotation curves. These data present a significant variation in the orbital velocity of matter at the same distances. By running real observational data through our model, we show that the density of the dark matter within them shows real complex structure, which is not suggested by other computational models. Our aim of this paper is to model this structure and then speculate as to the cause and implications of these density fluctuations.展开更多
Observed spiral galaxy rotation curves allow a measurement of the warm dark matter particle velocity dispersion and mass. The measured thermal relic mass m<sub>h </sub>≈100 eV is in disagreement ...Observed spiral galaxy rotation curves allow a measurement of the warm dark matter particle velocity dispersion and mass. The measured thermal relic mass m<sub>h </sub>≈100 eV is in disagreement with limits, typically in the range 1 to 4 keV. We review the measurements, update the no freeze-in and no freeze-out scenario of warm dark matter, and try to identify the cause of the discrepancies between measurements and limits.展开更多
The flat limit of rotational velocity (v<sub>φ</sub>) approximately equal to the “edge”-velocity of a galaxy is related to the baryonic mass (M<sub>B</sub>) via the T-F relationship w...The flat limit of rotational velocity (v<sub>φ</sub>) approximately equal to the “edge”-velocity of a galaxy is related to the baryonic mass (M<sub>B</sub>) via the T-F relationship with n ≈ 4. We explore the connection between mass and the limiting velocity in the framework of general relativity (GR) using the Weyl metric for axially-symmetric galaxies that are supported entirely by their rotational motion. While for small distances from the center, the Newtonian description is accurate as one moves beyond the (baryonic) edge of the galaxy, Lenz’s law and non-linearity of the gravitational field inherent in GR not only lead to a flat velocity (obviating its Keplerian fall), but also provide its tight log-log relationship with the enclosed (baryonic) mass.展开更多
Modified Newtonian dynamics (MOND) is a hypothesized modification of Newton’s law of universal gravitation to account for the flat rotation curves in the outer regions of galaxies, thereby eliminating the need for da...Modified Newtonian dynamics (MOND) is a hypothesized modification of Newton’s law of universal gravitation to account for the flat rotation curves in the outer regions of galaxies, thereby eliminating the need for dark matter. Although a highly successful model, it is not a self-contained physical theory since it is based entirely on observations. It is proposed in this paper that noncommutative geometry, an offshoot of string theory, can account for the flat rotation curves and thereby provide an explanation for MOND. This paper extends an earlier heuristic argument by the author.展开更多
Recent observations of Dwarf Satellite Galaxies (DSG) show that they have a clear tendency to stay in particular planes. Explanations with standard physics remain controversial. Recently, I proposed a new explanation ...Recent observations of Dwarf Satellite Galaxies (DSG) show that they have a clear tendency to stay in particular planes. Explanations with standard physics remain controversial. Recently, I proposed a new explanation of the galactic flat rotation curves, introducing a new cosmic acceleration due to expansion. In this paper, I apply this new acceleration to the dynamics of DSG’s (without dark matter). I show that this new acceleration implies planar structures for the DSG trajectories. More generally, it is shown that this acceleration produces a space structuration around any massive center. It remains a candidate to explain several cosmic observations without dark matter.展开更多
We derive the Schr6dinger equation of a particle constrained to move on a rotating curved surface S. Using the thin-layer quantization scheme to confine the particle on S, and with a proper choice of gauge transformat...We derive the Schr6dinger equation of a particle constrained to move on a rotating curved surface S. Using the thin-layer quantization scheme to confine the particle on S, and with a proper choice of gauge transformation for the wave function, we obtain the well-known geometric potentiM Vg and an additive Coriolis-induced geometric potential in the co-rotationM curvilinear coordinates. This novel effective potential, which is included in the surface Schr6dinger equation and is coupled with the mean curvature of S, contains an imaginary part in the general case which gives rise to a non-Hermitian surface Hamiltonian. We find that the non-Hermitian term vanishes when S is a minimal surface or a revolution surface which is axially symmetric around the rolling axis.展开更多
In Minkowski space M,we derive the effective Schrodinger equation describing a spin-less particle confined to a rotating curved surface S.Using the thin-layer quantization formalism to constrain the particle on we obt...In Minkowski space M,we derive the effective Schrodinger equation describing a spin-less particle confined to a rotating curved surface S.Using the thin-layer quantization formalism to constrain the particle on we obtain the relativity-corrected geometric potential V_(g)’,and a novel effective potential V(g) related to both the Gaussian curvature and the geodesic curvature of the rotating surface.The Coriolis effect and the centrifugal potential also appear in the equation.Subsequently,we apply the surface Schrodinger equation to a rotating cylinder,sphere and toms surfaces,in which we find that the interplays between the rotation and surface geometry can contribute to the energy spectrum based on the potentials they offer.展开更多
Analogous to a black body, the empty space surrounding a massive body is theoretically envisioned to radiate thermal gravitational energy in accordance with Planck’s radiation law. Gravitational black-body radiation ...Analogous to a black body, the empty space surrounding a massive body is theoretically envisioned to radiate thermal gravitational energy in accordance with Planck’s radiation law. Gravitational black-body radiation offers a remarkably compelling solution to the deep, long-standing questions concerning galaxy rotation curves and strong gravitational lensing by large astrophysical systems, without the need to impose a dark matter or massive graviton hypothesis. As with the quantized orbits of the electron in the atom and the classical physics of Maxwell’s theory of electromagnetism, gravitational black-body radiation represents a truly profound break from the classical physics of Einstein’s general theory of relativity and the emergence of the fundamental quantum nature of gravity.展开更多
A new model of the modified Newtonian gravity called Compacted & Collapsing Gravity (CCG) is proposed. Similar to the Milgrom’s MOND, it allows explaining the flattening of rotation curve in spiral galaxies, thus...A new model of the modified Newtonian gravity called Compacted & Collapsing Gravity (CCG) is proposed. Similar to the Milgrom’s MOND, it allows explaining the flattening of rotation curve in spiral galaxies, thus eliminates the need for dark matter at this level. However, in contrast to MOND, it puts a distinct limit on effective gravity;thereby constraints the sizes of single galaxies in connection to their masses, which complies with observations. In the bigger than single galaxies structures such as galaxy clusters, CCG rather complements than replaces interpretations of the observational data based on dark matter. Besides, the new model provides a plausible explanation to the hierarchical structure of the universe.展开更多
Owing to the renewed interest in dark matter after the upgrade of the large hadron collider and its dedication to dark-matter research, it is timely to reassess the whole problem. Considering dark matter is one way to...Owing to the renewed interest in dark matter after the upgrade of the large hadron collider and its dedication to dark-matter research, it is timely to reassess the whole problem. Considering dark matter is one way to reconcile the discrepancy between the velocity of matter in the outer regions of galaxies and the observed galactic mass. Thus far, no credible candidate for dark matter has been identified. Here, we develop a model accounting for observations by rotations and interactions between rotating objects analogous to magnetic fields and interactions with moving charges. The magnitude of these fields is described by a fundamental constant on the order of 10^-41kg^-1. The same interactions can be observed in the solar system, where they lead to small changes in planetary orbits.展开更多
The observed rotation curves of low surface brightness(LSB)galaxies play an essential role in studying dark matter,and indicate the existence of a central constant density dark matter core.However,the cosmological N-b...The observed rotation curves of low surface brightness(LSB)galaxies play an essential role in studying dark matter,and indicate the existence of a central constant density dark matter core.However,the cosmological N-body simulations of cold dark matter predict an inner cusped halo with a power-law mass density distribution,and cannot reproduce a central constant-density core.This phenomenon is called cusp-core problem.When dark matter is quiescent and satisfies the condition for hydrostatic equilibrium,the equation of state can be adopted to obtain the density profile in the static and spherically symmetric space-time.To address the cusp-core problem,we assume that the equation of state is independent of the scaling transformation.Its lower order approximation for this type of equation of state can naturally lead to a special case,i.e.,■,where p andρrepresent the pressure and density,respectively,V_(rot) depicts the rotation velocity of galaxy,andζandεare positive constants.It can obtain a density profile that is similar to the pseudo-isothermal halo model whenεis approximately 0.15.To obtain a more universally used model,let the equation of state include the polytropic model,i.e.■,from which we can obtain other types of density profiles,such as the profile that is nearly same as the Burkert profile,where s and ρ_(0) are positive constants.展开更多
The flow and convected heat transfer of the Oldroyd-B fluids in a rotating curved pipe with circular cross-section were investigated by employing a perturbation method. A perturbation solution up to the second order w...The flow and convected heat transfer of the Oldroyd-B fluids in a rotating curved pipe with circular cross-section were investigated by employing a perturbation method. A perturbation solution up to the second order was obtained for a small curvature ratio, κ. The variations of axial velocity distribution and secondary flow structure with F, Re and We were discussed in detail in order to investigate the combined effects of the three parameters on flow structure. The combined effects of the Coriolis force, inertia force and elastic force on the temperature distribution were also analyzed, which are greater than the adding independent effects of the three forces. The variations of the flow rate and Nusselt number with the rotation, inertia and elasticity were examined as well. The results show the characteristics of the heat and mass transfer of the Oldroyd-B fluids in a rotating curved pipe.展开更多
WT5”BZ]In this paper, the flow in a rotating curved annular pipe is examined by a perturbation method. A second order perturbation solution is presented. The characteristics of the secondary flow and the axial flow a...WT5”BZ]In this paper, the flow in a rotating curved annular pipe is examined by a perturbation method. A second order perturbation solution is presented. The characteristics of the secondary flow and the axial flow are studied in detail. The study indicates that the loops of the secondary flow are more complex than those in a curved annular pipe without rotation and its numbers depend on the ratio of the Coriolis force to centrifugal force F. As F≈-1, the secondary flow has eight loops and its intensity reaches the minimum value, and the distribution of the axial flow is like that of the Poiseuille flow. The position of the maximum axial velocity is pushed to either outer bend or inner bend, which is also determined by F. [WT5”HZ]展开更多
We study the evolution of the particle number concentration, mass concentration, particle polydispersity, particle diameter and geometric standard deviation considering particle coagulation and dispersion in a rotatin...We study the evolution of the particle number concentration, mass concentration, particle polydispersity, particle diameter and geometric standard deviation considering particle coagulation and dispersion in a rotating curved pipe at different Reynolds number, Schmidt number and F number. It is found that, when the Coriolis force and the centrifugal force point to the same direction, particles concentrate near the outside edge of the pipe, which becomes more obvious as time goes by. The particle number and mass concentration increase faster at the early stage than that at the later stage, and approach a stable value finally. As the coagulation proceeds, the particle diameter, polydispersity and geometric standard deviation increase and have high values in the region close to the outside edge of the pipe. When the Coriolis force and the centrifugal force point to the oppo- site direction and the Coriolis force is more dominant than the centrifugal force, particles concentrate near the inside edge of the pipe. The particles in the region with a high number concentration have high mass concentration, large diameter and high polydispersity as well as large geometric standard deviation. The particle distribution is dependent on the balance of the pipe curvature and rotating speed. The Reynolds number and the Schmidt number have effects on the particle distribution when other parameters remain unchanged. An increase in the Reynolds number leads to an increase in particle number concentration and mass concentration, and a decrease in particle polydispersity, particle diameter and geometric standard deviation. With the increase of Schmidt number the particle number concentration and mass concentration increase, and the particle polydispersity, particle diameter and geometric standard deviation decrease.展开更多
Three-dimensional laminar flow in the entrance region of rotating curved pipes was investigated. The governing equations were written in an orthogonal curvilinear coordinate system and solved with a fully three-dimens...Three-dimensional laminar flow in the entrance region of rotating curved pipes was investigated. The governing equations were written in an orthogonal curvilinear coordinate system and solved with a fully three-dimensional numerical method. The development of secondary flow, axial velocity, local and average friction factors for different cases of rotation were given and discussed in detail. The results show that rotation influences the flow structure and friction factor greatly and that the secondary flow is sink-type in the early stage of development and then turns to vortex structure. The average friction factor and the intensity of secondary flow have drastic decrease near the entrance. At some proper rotation, the average friction factor can be noticeably reduced.展开更多
文摘Supermassive DEOs (SMDEOs) are cosmologically evolved objects made of irreducible incompressible supranuclear dense superfluids: The state we consider to govern the matter inside the cores of massive neutron stars. These cores are practically trapped in false vacua, rendering their detection by outside observers impossible. Based on massive parallel computations and theoretical investigations, we show that SMDEOs at the centres of spiral galaxies that are surrounded by massive rotating torii of normal matter may serve as powerful sources for gravitational waves carrying away roughly 1042 erg/s. Due to the extensive cooling by GWs, the SMDEO-Torus systems undergo glitching, through which both rotational and gravitational energies are abruptly ejected into the ambient media, during which the topologies of the embedding spacetimes change from curved into flatter ones, thereby triggering a burst gravitational energy of order 1059 erg. Also, the effects of glitches found to alter the force balance of objects in the Lagrangian-L1 region between the central SMDEO-Torus system and the bulge, enforcing the enclosed objects to develop violent motions, that may explain the origin of the rotational curve irregularities observed in the innermost part of spiral galaxies. Our study shows that the generated GWs at the centres of galaxies, which traverse billions of objects during their outward propagations throughout the entire galaxy, lose energy due to repeatedly squeezing and stretching the objects. Here, we find that these interactions may serve as damping processes that give rise to the formation of collective forces f∝m(r)/r, that point outward, endowing the objects with the observed flat rotation curves. Our approach predicts a correlation between the baryonic mass and the rotation velocities in galaxies, which is in line with the Tully-Fisher relation. The here-presented self-consistent approach explains nicely the observed rotation curves without invoking dark matter or modifying Newtonian gravitation in the low-field approximation.
文摘There is a significant difference between the calculation based on the theory of general relativity and observation of rotation curves of spiral galaxies. To describe this discrepancy, two distinct theories have been proposed so far： existence of dark matter and modification of underlying gravitational theory. In the absence of dark matter, it is assumed that the theory of general relativity on galactic scales needs to be modified. This letter is devoted to explaining this difference in a modified teleparMIeI gravity. We show that modified teleparallel gravity favors flatness of rotation curves of spiral galaxies much in the same way as observation shows.
文摘Warm dark matter has, by definition, a velocity dispersion. Let v<sub>hms</sub>(a)=v<sub>hms</sub><sub></sub>(1)/a be the root-mean-square velocity of non-relativistic warm dark matter particles in the early universe at expansion parameter a. v<sub>hms</sub><sub></sub>(1) is an adiabatic invariant. We obtain v<sub>hms</sub><sub></sub>(1) in the core of 11 dwarf galaxies dominated by dark matter, from their observed rotation curves, up to a rotation and relaxation correction. We obtain a mean 0.490 km/s and standard deviation 0.160 km/s, with a distribution peaked at the lower end. We apply a mild, data driven, rotation and relaxation correction that obtains the adiabatic invariant in the core of the galaxies: v<sub>hms</sub></sub>(1)=0.406 ±0.069 km/s. These two small relative standard deviations justify the prediction that the adiabatic invariant v<sub>hms</sub><sub></sub>(1) in the core of the galaxies is of cosmological origin if dark matter is warm. This result is in agreement with measurements of v<sub>hms</sub></sub>(1) based on spiral galaxy rotation curves, galaxy ultra-violet luminosity distributions, galaxy stellar mass distributions, the formation of first galaxies, reionization, and the velocity dispersion cut-off mass.
文摘The pictures from the James Webb Space Telescope (JWST) suggest that massive galaxies were already at the beginning of the expansion of the Universe because there was too short time to create them. It is consistent with the new cosmology presented within the Scale-Symmetric Theory (SST). The phase transitions of the initial inflation field described in SST lead to the Protoworld—its core was built of dark matter (DM). We show that the DAMA/LIBRA annual-modulation amplitude forced by the change of the Earth’s velocity (i.e. baryonic-matter (BM) velocity) in relation to the spinning DM field in our Galaxy’s halo should be very low. We calculated that in the DM-BM weak interactions are created single and entangled spacetime condensates with a lowest mass/energy of 0.807 keV—as the Higgs boson they can decay to two photons, so we can indirectly detect DM. Our results are consistent with the averaged DAMA/LIBRA/COSINE-100 curve describing the dependence of the event rate on the photon energy in single-hit events. We calculated the mean dark-matter-halo (DMH) mass around quasars, we also described the origin of the plateaux in the rotation curves for the massive spiral galaxies, the role of DM-loops in magnetars, the origin of CMB, the AGN-jet and galactic-halo production, and properties of dark energy (DE).
文摘The radical hypothesis concerning the physics of gravitational black-body radiation is placed on a more solid statistical mechanics foundation in this study. As the concepts and formalism in the former presentation are only partially developed and furthermore, suffer from an unfortunate misstep regarding Hawking radiation and the hypothetical gravitational black-body temperature of a parcel or distribution of energy;this paper aims to fill in some of the theoretical gaps in the derivation of the Planck radiation formula for gravity (or non-Euclidean space-time), and there by provide a more complete and transparent quantum theory of thermal gravitational radiation.
文摘Understanding the dark matter distribution throughout a galaxy can provide insight into its elusive nature. Numerous density profiles, such as the Navarro, Frenk and White model, have been created in an attempt to study this distribution through analyzing orbital velocities of luminous matter and modeling dark matter distributions to explain these observations. However, we are interested in a simple model to consider the significant fluctuations in rotation curves at larger radii. Therefore, our model is much simpler compared to those previously mentioned. Our model used all the observational data available for four selected galactic rotation curves. These data present a significant variation in the orbital velocity of matter at the same distances. By running real observational data through our model, we show that the density of the dark matter within them shows real complex structure, which is not suggested by other computational models. Our aim of this paper is to model this structure and then speculate as to the cause and implications of these density fluctuations.
文摘Observed spiral galaxy rotation curves allow a measurement of the warm dark matter particle velocity dispersion and mass. The measured thermal relic mass m<sub>h </sub>≈100 eV is in disagreement with limits, typically in the range 1 to 4 keV. We review the measurements, update the no freeze-in and no freeze-out scenario of warm dark matter, and try to identify the cause of the discrepancies between measurements and limits.
文摘The flat limit of rotational velocity (v<sub>φ</sub>) approximately equal to the “edge”-velocity of a galaxy is related to the baryonic mass (M<sub>B</sub>) via the T-F relationship with n ≈ 4. We explore the connection between mass and the limiting velocity in the framework of general relativity (GR) using the Weyl metric for axially-symmetric galaxies that are supported entirely by their rotational motion. While for small distances from the center, the Newtonian description is accurate as one moves beyond the (baryonic) edge of the galaxy, Lenz’s law and non-linearity of the gravitational field inherent in GR not only lead to a flat velocity (obviating its Keplerian fall), but also provide its tight log-log relationship with the enclosed (baryonic) mass.
文摘Modified Newtonian dynamics (MOND) is a hypothesized modification of Newton’s law of universal gravitation to account for the flat rotation curves in the outer regions of galaxies, thereby eliminating the need for dark matter. Although a highly successful model, it is not a self-contained physical theory since it is based entirely on observations. It is proposed in this paper that noncommutative geometry, an offshoot of string theory, can account for the flat rotation curves and thereby provide an explanation for MOND. This paper extends an earlier heuristic argument by the author.
文摘Recent observations of Dwarf Satellite Galaxies (DSG) show that they have a clear tendency to stay in particular planes. Explanations with standard physics remain controversial. Recently, I proposed a new explanation of the galactic flat rotation curves, introducing a new cosmic acceleration due to expansion. In this paper, I apply this new acceleration to the dynamics of DSG’s (without dark matter). I show that this new acceleration implies planar structures for the DSG trajectories. More generally, it is shown that this acceleration produces a space structuration around any massive center. It remains a candidate to explain several cosmic observations without dark matter.
基金Supported by the National Natural Science Foundation of China under Grants Nos 11047020,11404157,11274166,11275097,11475085 and 11535005the Natural Science Foundation of Shangdong Province under Grants Nos ZR2012AM022 and ZR2011AM019
文摘We derive the Schr6dinger equation of a particle constrained to move on a rotating curved surface S. Using the thin-layer quantization scheme to confine the particle on S, and with a proper choice of gauge transformation for the wave function, we obtain the well-known geometric potentiM Vg and an additive Coriolis-induced geometric potential in the co-rotationM curvilinear coordinates. This novel effective potential, which is included in the surface Schr6dinger equation and is coupled with the mean curvature of S, contains an imaginary part in the general case which gives rise to a non-Hermitian surface Hamiltonian. We find that the non-Hermitian term vanishes when S is a minimal surface or a revolution surface which is axially symmetric around the rolling axis.
基金jointly supported by the National Nature Science Foundation of China(Grants No.11774157,No.11934008,No.12075117,No.51721001,No.11890702,No.11625418,No.11535005,No.11690030)funded by the Natural Science Foundation of Shandong Province of China(Grant No.ZR2020MA091)。
文摘In Minkowski space M,we derive the effective Schrodinger equation describing a spin-less particle confined to a rotating curved surface S.Using the thin-layer quantization formalism to constrain the particle on we obtain the relativity-corrected geometric potential V_(g)’,and a novel effective potential V(g) related to both the Gaussian curvature and the geodesic curvature of the rotating surface.The Coriolis effect and the centrifugal potential also appear in the equation.Subsequently,we apply the surface Schrodinger equation to a rotating cylinder,sphere and toms surfaces,in which we find that the interplays between the rotation and surface geometry can contribute to the energy spectrum based on the potentials they offer.
文摘Analogous to a black body, the empty space surrounding a massive body is theoretically envisioned to radiate thermal gravitational energy in accordance with Planck’s radiation law. Gravitational black-body radiation offers a remarkably compelling solution to the deep, long-standing questions concerning galaxy rotation curves and strong gravitational lensing by large astrophysical systems, without the need to impose a dark matter or massive graviton hypothesis. As with the quantized orbits of the electron in the atom and the classical physics of Maxwell’s theory of electromagnetism, gravitational black-body radiation represents a truly profound break from the classical physics of Einstein’s general theory of relativity and the emergence of the fundamental quantum nature of gravity.
文摘A new model of the modified Newtonian gravity called Compacted & Collapsing Gravity (CCG) is proposed. Similar to the Milgrom’s MOND, it allows explaining the flattening of rotation curve in spiral galaxies, thus eliminates the need for dark matter at this level. However, in contrast to MOND, it puts a distinct limit on effective gravity;thereby constraints the sizes of single galaxies in connection to their masses, which complies with observations. In the bigger than single galaxies structures such as galaxy clusters, CCG rather complements than replaces interpretations of the observational data based on dark matter. Besides, the new model provides a plausible explanation to the hierarchical structure of the universe.
文摘Owing to the renewed interest in dark matter after the upgrade of the large hadron collider and its dedication to dark-matter research, it is timely to reassess the whole problem. Considering dark matter is one way to reconcile the discrepancy between the velocity of matter in the outer regions of galaxies and the observed galactic mass. Thus far, no credible candidate for dark matter has been identified. Here, we develop a model accounting for observations by rotations and interactions between rotating objects analogous to magnetic fields and interactions with moving charges. The magnitude of these fields is described by a fundamental constant on the order of 10^-41kg^-1. The same interactions can be observed in the solar system, where they lead to small changes in planetary orbits.
基金Supported by the National Natural Science Foundation(NSF)of China(11973081,11573062,11403092,11390374,11521303)the YIPACAS Foundation(2012048)+2 种基金the Chinese Academy of Sciences(CAS,KJZD-EW-M06-01)the NSF of Yunnan Province(2019FB006)the Youth Project of Western Light of CAS。
文摘The observed rotation curves of low surface brightness(LSB)galaxies play an essential role in studying dark matter,and indicate the existence of a central constant density dark matter core.However,the cosmological N-body simulations of cold dark matter predict an inner cusped halo with a power-law mass density distribution,and cannot reproduce a central constant-density core.This phenomenon is called cusp-core problem.When dark matter is quiescent and satisfies the condition for hydrostatic equilibrium,the equation of state can be adopted to obtain the density profile in the static and spherically symmetric space-time.To address the cusp-core problem,we assume that the equation of state is independent of the scaling transformation.Its lower order approximation for this type of equation of state can naturally lead to a special case,i.e.,■,where p andρrepresent the pressure and density,respectively,V_(rot) depicts the rotation velocity of galaxy,andζandεare positive constants.It can obtain a density profile that is similar to the pseudo-isothermal halo model whenεis approximately 0.15.To obtain a more universally used model,let the equation of state include the polytropic model,i.e.■,from which we can obtain other types of density profiles,such as the profile that is nearly same as the Burkert profile,where s and ρ_(0) are positive constants.
基金the National Natural Science Foundation of China(Grant No. 10272096).
文摘The flow and convected heat transfer of the Oldroyd-B fluids in a rotating curved pipe with circular cross-section were investigated by employing a perturbation method. A perturbation solution up to the second order was obtained for a small curvature ratio, κ. The variations of axial velocity distribution and secondary flow structure with F, Re and We were discussed in detail in order to investigate the combined effects of the three parameters on flow structure. The combined effects of the Coriolis force, inertia force and elastic force on the temperature distribution were also analyzed, which are greater than the adding independent effects of the three forces. The variations of the flow rate and Nusselt number with the rotation, inertia and elasticity were examined as well. The results show the characteristics of the heat and mass transfer of the Oldroyd-B fluids in a rotating curved pipe.
文摘WT5”BZ]In this paper, the flow in a rotating curved annular pipe is examined by a perturbation method. A second order perturbation solution is presented. The characteristics of the secondary flow and the axial flow are studied in detail. The study indicates that the loops of the secondary flow are more complex than those in a curved annular pipe without rotation and its numbers depend on the ratio of the Coriolis force to centrifugal force F. As F≈-1, the secondary flow has eight loops and its intensity reaches the minimum value, and the distribution of the axial flow is like that of the Poiseuille flow. The position of the maximum axial velocity is pushed to either outer bend or inner bend, which is also determined by F. [WT5”HZ]
基金supported by the National Natural Science Foundation of China (Grant No. 10632070)
文摘We study the evolution of the particle number concentration, mass concentration, particle polydispersity, particle diameter and geometric standard deviation considering particle coagulation and dispersion in a rotating curved pipe at different Reynolds number, Schmidt number and F number. It is found that, when the Coriolis force and the centrifugal force point to the same direction, particles concentrate near the outside edge of the pipe, which becomes more obvious as time goes by. The particle number and mass concentration increase faster at the early stage than that at the later stage, and approach a stable value finally. As the coagulation proceeds, the particle diameter, polydispersity and geometric standard deviation increase and have high values in the region close to the outside edge of the pipe. When the Coriolis force and the centrifugal force point to the oppo- site direction and the Coriolis force is more dominant than the centrifugal force, particles concentrate near the inside edge of the pipe. The particles in the region with a high number concentration have high mass concentration, large diameter and high polydispersity as well as large geometric standard deviation. The particle distribution is dependent on the balance of the pipe curvature and rotating speed. The Reynolds number and the Schmidt number have effects on the particle distribution when other parameters remain unchanged. An increase in the Reynolds number leads to an increase in particle number concentration and mass concentration, and a decrease in particle polydispersity, particle diameter and geometric standard deviation. With the increase of Schmidt number the particle number concentration and mass concentration increase, and the particle polydispersity, particle diameter and geometric standard deviation decrease.
基金Project supported by the National Natural Science Foundation of China (Grant No: 10272096).
文摘Three-dimensional laminar flow in the entrance region of rotating curved pipes was investigated. The governing equations were written in an orthogonal curvilinear coordinate system and solved with a fully three-dimensional numerical method. The development of secondary flow, axial velocity, local and average friction factors for different cases of rotation were given and discussed in detail. The results show that rotation influences the flow structure and friction factor greatly and that the secondary flow is sink-type in the early stage of development and then turns to vortex structure. The average friction factor and the intensity of secondary flow have drastic decrease near the entrance. At some proper rotation, the average friction factor can be noticeably reduced.
