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Complex Field Theory: A Unifying Framework for Dark Matter and Dark Energy with the Material Universe
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作者 Hossin Abdeldayem 《Journal of Modern Physics》 2025年第1期140-151,共12页
Complex Field Theory (CFT) proposes that dark matter (DM) and dark energy (DE) are pervasive, complex fields of charged complex masses of equally positive and negative complex charges, respectively. It proposes that e... Complex Field Theory (CFT) proposes that dark matter (DM) and dark energy (DE) are pervasive, complex fields of charged complex masses of equally positive and negative complex charges, respectively. It proposes that each material object, including living creatures, is concomitant with a fraction of the charged complex masses of DM and DE in proportion to its mass. This perception provides new insights into the physics of nature and its constituents from subatomic to cosmic scales. This complex nature of DM and DE explains our inability to see DM or harvest DE for the last several decades. The positive complex DM is responsible for preserving the integrity of galaxies and all material systems. The negative complex charged DE induces a positive repelling force with the positively charged DM and contributes to the universe’s expansion. Both fields are Lorentz invariants in all directions and entangle the whole universe. The paper uses CFT to investigate zero-point energy, particle-wave duality, relativistic mass increase, and entanglement phenomenon and unifies Coulomb’s and Newton’s laws. The paper also verifies the existence of tachyons and explains the spooky action of quantum mechanics at a distance. The paper encourages further research into how CFT might resolve several physical mysteries in physics. 展开更多
关键词 dark Energy dark Matter Complex Field Theory Entanglement Zero-Point Energy Particle-Wave Duality Gravity Unification of Coulomb’s and Newton’s Laws TACHYONS Spooky Action Effect
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A Dark Energy Hypothesis IV
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作者 James Togeas 《Journal of High Energy Physics, Gravitation and Cosmology》 2025年第1期45-55,共11页
The subject is the thermodynamics of dark matter, the Helmholtz free energy. The method of fluctuations leads to an estimate of the mass of a dark matter particle. The picture that emerges is that of a small-mass, deg... The subject is the thermodynamics of dark matter, the Helmholtz free energy. The method of fluctuations leads to an estimate of the mass of a dark matter particle. The picture that emerges is that of a small-mass, degenerate, spinless boson. Contour integration produces dark matter equations of state. 展开更多
关键词 dark Matter Helmholtz Free Energy FLUCTUATIONS FUGACITY BE Gas and Condensate
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A Dark Energy Hypothesis III
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作者 James Togeas 《Journal of High Energy Physics, Gravitation and Cosmology》 2025年第1期39-44,共6页
The subject is the thermodynamics of dark energy. Thermodynamically, the ratio of dark energy to CMR temperature has the units of entropy, has a well-defined numerical value at every moment of cosmological history, an... The subject is the thermodynamics of dark energy. Thermodynamically, the ratio of dark energy to CMR temperature has the units of entropy, has a well-defined numerical value at every moment of cosmological history, and increases in time monotonically without limit. The proposal is that it is the cosmological entropy, aka dark entropy. Discussion compares it to other notions of entropy. Dark entropy is a necessary prelude to DEH IV, which is about the thermodynamics of dark matter. 展开更多
关键词 dark Energy ENTROPY Second Law
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Dark Galaxies, Sun-Earth-Moon Interaction, Tunguska Event—Explained by WUM
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作者 Vladimir S. Netchitailo 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第2期836-853,共18页
Great experimental results and observations achieved by Astronomy in the last decades revealed new unexplainable phenomena. Astronomers have conclusive new evidence that a recently discovered “dark galaxy” is, in fa... Great experimental results and observations achieved by Astronomy in the last decades revealed new unexplainable phenomena. Astronomers have conclusive new evidence that a recently discovered “dark galaxy” is, in fact, an object the size of a galaxy, made entirely of dark matter. They found that the speed of the Earth’s rotation varies randomly each day. 115 years ago, the Tunguska Event was observed, and astronomers still do not have an explanation of It. Main results of the present article are: 1) Dark galaxies explained by the spinning of their Dark Matter Cores with the surface speed at equator less than the escape velocity. Their Rotational Fission is not happening. Extrasolar systems do not emerge;2) 21-cm Emission explained by the self-annihilation of Dark Matter particles XIONs (5.3 μeV);3) Sun-Earth-Moon Interaction explained by the influence of the Sun’s and the Moon’s magnetic field on the electrical currents of the charged Geomagma (the 660-km layer), and, as a result, the Earth’s daylength varies;4) Tunguska Event explained by a huge atmospheric explosion of the Superbolide, which was a stable Dark Matter Bubble before entering the Earth’s atmosphere. 展开更多
关键词 World-Universe Model dark Stars dark Galaxies 21-cm Emission Formation of Macrostructures Sun-Earth-Moon Interaction Tunguska Event dark Matter
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A Dark Matter Theory by Quantum Gravitation for Galaxies and Clusters
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作者 Manuel Abarca 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1749-1784,共36页
This paper develops an original theory of dark matter in the current ΛCDM framework, whose main hypothesis is that DM is generated by the own gravitational field, according to an unknown quantum gravitational phenome... This paper develops an original theory of dark matter in the current ΛCDM framework, whose main hypothesis is that DM is generated by the own gravitational field, according to an unknown quantum gravitational phenomenon. This work is the best version of the theory, which I have been developing and publishing since 2014. The hypothesis of DM by quantum gravitation, DMbQG hereafter, has two main consequences: the first one is that the law of DM generation has to be the same, in the halo region, for all the galaxies and the second one is that the haloes are unbounded, so the total DM goes up without limit as the gravitational field is unbounded as well. The first one consequence is backed by the fact that M31 and MW has a fitted function with the same power exponent for the rotation curve at the halo region and both giant galaxies are the only ones whose rotation curves at the halo region may be studied with accuracy. This paper is firstly developed all the theory with M31 rotation curve data up to Chapter 9. The most important formula of the theory is the called Direct mass, which calculates the total mass at a specific radius into the halo region. Chapter 10 is dedicated to apply the theory to Milky Way, it is calculated its total mass at different radius into the halo and such results have been validated successfully using the data of masses at different radius published by two researcher teams. In Chapter 11, it is calculated the direct mass for the Local Group, and it is shown how the DMbQG theory is able to calculate the total mass at 770 kpc, that the dynamical methods estimate to be 5×1012MΘ. In Chapter 12, it is shown a method to estimate the Direct mass formula for a cluster of galaxies, using only its virial mass and virial radius. By this method, it is estimated the parameter a2 of the Local Group, which match with the one calculated in previous chapter by a different method. Also are calculated the parameters a2 associated to Virgo and Coma clusters. In Chapter 13, it is demonstrated how the DE is able to counterbalance the DM at cluster scale, as the Direct mass grows up with the square root of radius whereas the DE grows up with the cubic power. The chapter is an introduction to the DMbQG theory for cluster of galaxies, which has been developed fully by the author in other works. This theory aims to be a powerful method to study DM in the halo region of galaxies and cluster of galaxies and conversely the measures in galaxies and clusters offer the possibility to validate the theory. 展开更多
关键词 dark Matter dark Energy GALAXIES Local Group of Galaxies CLUSTERS
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The Origin, Properties and Detection of Dark Matter and Dark Energy
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作者 Sylwester Kornowski 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第2期749-774,共26页
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
关键词 New Cosmology dark Matter DM-BM Weak Interactions DMH Mass around Quasars Rotation Curves of Galaxies MAGNETARS CMB AGN-Jet Production Galactic-Halo Production dark Energy
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A Dark Energy Hypothesis I
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作者 James Togeas 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第3期1138-1141,共4页
The cosmological constant, Λ, represents dark energy. The dark energy hypothesis (DEH) replaces Λ with a variable quantity, the cosmological parameter: Λ=1a2η2In this formula, “a” is the scale factor and η the ... The cosmological constant, Λ, represents dark energy. The dark energy hypothesis (DEH) replaces Λ with a variable quantity, the cosmological parameter: Λ=1a2η2In this formula, “a” is the scale factor and η the conformal time: adη = cdt. A companion paper (DEH II) develops and explores a cosmological model with this variable parameter. This paper portrays the origin of the cosmological parameter in the uncoupling of time and space in the early universe from a prior state in which the comoving coordinates x0 = η and x1 = χ, the cosmic latitude, are coupled. In this hypothesis dark matter is a co-product of the decoupling, but its nature remains mysterious. 展开更多
关键词 dark Energy dark Matter Cosmological Constant Tensor Calculus
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Solving the Conundrum of Dark Matter and Dark Energy in Galaxy Clusters
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作者 Manuel Abarca 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1785-1805,共21页
This paper develops the Dark Matter by Quantum Gravitation theory, DMbQG theory hereafter, in clusters of galaxies in the cosmologic model ΛCDM of the Universe. Originally this theory was developed by the author for ... This paper develops the Dark Matter by Quantum Gravitation theory, DMbQG theory hereafter, in clusters of galaxies in the cosmologic model ΛCDM of the Universe. Originally this theory was developed by the author for galaxies, especially using MW and M31 rotation curves. An important result got by the DMbQG theory is that the total mass associated to a galactic halo depend on the square root of radius, being its dominion unbounded. Apparently, this result would be absurd because of divergence of the total mass. As the DE is negligible at galactic scale, it is needed to extend the theory to clusters in order to study the capacity of DE to counterbalance to DM. Thanks this property, the DMbQG theory finds unexpected theoretical results. In this work, it is defined, the total mass as baryonic matter plus DM and the gravitating mass as the addition of the total mass plus the negative mass associated to dark energy. In clusters it is defined the zero gravity radius (RZG hereafter) as the radius needed by the dark energy to counterbalance the total mass. It has been found that the ratio RZG/RVIRIAL ≈ 7.3 and its Total mass associated at RZG is ≈2.7 MVIRIAL. In addition, it has been calculated that the sphere with the extended halo radius RE = 1.85 RZG has a ratio DM density versus DE density equal to 3/7 and its total mass associated at RE is ≈3.6 MVIRIAL. This works postulates that the factor 3.6 may equilibrate perfectly the strong imbalance between the Local mater density parameter (0.08) versus the current Global matter density one (0.3). Currently, this fact is a big conundrum in cosmology, see chapter 7. Also it has been found that the zero velocity radius, RZV hereafter, i.e. the cluster border because of the Hubble flow, is ≈0.6 RZG and its gravitating mass is ≈ 1.5 MVIR. By derivation of gravitating mass function, it is calculated that at 0.49 RZG, this function reaches its maximum whose value is ≈1.57 MVIR. Throughout the paper, some of these results have been validated with recent data published for the Virgo cluster. As Virgo is the nearest big cluster, it is the perfect benchmark to validate any new theory about DM and DE. These new theoretical findings offer to scientific community a wide number of tests to validate or reject the theory. The validation of DMbQG theory would mean to know the nature of DM that at the present, it is an important challenge for the astrophysics science. 展开更多
关键词 dark Matter dark Energy Galaxy Clusters Quantum Gravitation
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A Dark Energy Hypothesis II
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作者 James Togeas 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第3期1142-1151,共10页
The article develops a cosmological model based on a hypothesis that dark energy is a cosmological variable rather than a constant. A companion paper (DEH I) derives a formula for this variable cosmological parameter ... The article develops a cosmological model based on a hypothesis that dark energy is a cosmological variable rather than a constant. A companion paper (DEH I) derives a formula for this variable cosmological parameter as well as an argument that the early universe produces it and dark matter. The developed model leads to a series of self-consistent results including a prediction that provides a test for it. The results include comparisons of the DEH and the ΛCDM theory. 展开更多
关键词 dark Energy dark Matter Cosmological Constant Coupling of Space and Time
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A Many Worlds Interpretation of the Dark Universe
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作者 Richard Douglas Bateson 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第2期828-835,共8页
In this paper, we discuss a Many Worlds Interpretation (MWI) of Dark Energy and Dark Matter. The universe is viewed cosmologically as a fermionic fluid with a hydrostatic pressure from “Zitterbewegung”, the quantum ... In this paper, we discuss a Many Worlds Interpretation (MWI) of Dark Energy and Dark Matter. The universe is viewed cosmologically as a fermionic fluid with a hydrostatic pressure from “Zitterbewegung”, the quantum “zig-zagging” of Dirac particles. At each point in space-time, the pressure from all possible velocity states existing in the Many Worlds sums to provide a dark energy. This provides a ratio of matter energy to pressure energy close to that observed experimentally. Visible matter is the matter observed or measured in a particular velocity state and dark matter is then considered as the unobserved fermion contributions from different orthogonal spatial directions. 展开更多
关键词 dark Energy dark Matter Many Worlds
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Dark Matter and Dark Energy from Lattice Model of Universe
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作者 Branislav Majerník 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第3期1045-1053,共9页
The article considers a conceptual universe model as a periodic lattice (network) with nodes defined by the wave function in a background-independent Hamiltonian based on their relations and interactions. This model g... The article considers a conceptual universe model as a periodic lattice (network) with nodes defined by the wave function in a background-independent Hamiltonian based on their relations and interactions. This model gives rise to energy bands, similar to those in semiconductor solid-state models. In this context, valence band holes are described as dark matter particles with a heavy effective mass. The conducting band, with a spontaneously symmetry-breaking energy profile, contains particles with several times lighter effective mass, which can represent luminous matter. Some possible analogies with solid-state physics, such as the comparison between dark and luminous matter, are discussed. Additionally, tiny dark energy, as intrinsic lattice Casimir energy, is calculated for a lattice with a large number of lattice nodes. 展开更多
关键词 dark Energy dark Matter Lattice Universe Model
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Dynamic Spacetime: Key to the Mysteries of Dark Matter and Dark Energy
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作者 Tianxi Zhang 《Journal of Modern Physics》 2024年第4期416-434,共19页
Physics is a branch of science to study matter and its motion in space and time. Development of physics usually upgrades human perspective and understanding of the space and time. Einstein successfully developed speci... Physics is a branch of science to study matter and its motion in space and time. Development of physics usually upgrades human perspective and understanding of the space and time. Einstein successfully developed special and general theories of relativity and creatively promoted our perspective of spacetime from Newton’s absolute space and time to his relative spacetime. Based on redshift and distance measurements of galaxies and distant type Ia supernovae, cosmologists have suggested that our universe is expanding at an ever-increasing rate driven by a mysterious dark energy. Recently, the author has proposed that spacetime is dynamic. Spacetime is said to be absolute if it is independent of matter and motion, relative if it is affected by matter and motion, and dynamic if it mutually interacts with matter and motion. In dynamic spacetime, not only do matter and motion distort spacetime, but they are also affected by the distorted spacetime. Spacetime to be dynamic is a consequence of a deep insight to Mach’s principle, which tells us that the inertia of an object results from the gravitational interaction by the rest of the universe. Reaction of dynamic spacetime on a traveling light causes light redshift. Reaction of dynamic spacetime on a fast moving neutrino slows down the neutrino. The derived redshift-distance relation perfectly explained the measurements of distant type Ia supernovae and gamma ray bursts (GRBs) and also naturally obtained Hubble’s law as an approximate relation at small redshift. This explanation of cosmological redshift as the opposition of dynamic spacetime does not mandate the universe to be expanding and accelerating, so that it does not need the universe to be initiated from a Big Bang and driven out mainly by a mysterious dark energy. Extremely slowed down neutrinos in dynamic spacetime, when they are gravitationally trapped around clusters, galaxies, and any celestial objects, would play the role of dark matter in explaining the velocity-radius relations of galaxy’s or cluster’s rotations. 展开更多
关键词 SPACETIME Cosmology REDSHIFT NEUTRINO GRAVITATION dark Matter dark Energy
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Dark Energy Attenuation Based Modification of Newton’s Law of Gravity: A Theoretical Support to Milgrom’s MOND Concept
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作者 Ramanujam G. Alagar R. Prakash Pranav U. V. Sivanesh 《Journal of Modern Physics》 2024年第12期2013-2022,共10页
The Concept of MOND (Modifying Newtonian Dynamics) was proposed by Mordehai Milgrom as a possible way to reconcile the difference between the experimentally observed high values and the calculated values using Newton... The Concept of MOND (Modifying Newtonian Dynamics) was proposed by Mordehai Milgrom as a possible way to reconcile the difference between the experimentally observed high values and the calculated values using Newton’s Law of Gravity for the dynamical parameters of orbiting stars in a galaxy, without having to introduce the concept of dark matter. Milgrom’s MOND concept challenges the need for dark matter to account for the above difference. The experimentally observed velocity rotation curves of stars in a galaxy show that for small values of r (distance of the star from the centre of the galaxy), the velocity observed (VO) for the orbiting star fairly agrees with values (VN) calculated using Newton’s law of gravity. But as r increases, the difference between VO and VN gradually increases. For very large values of r, VO increases with a constant slope. Finally, VO becomes fairly constant with distance. The above features of VO cannot be explained by Newton’s law of gravity. Milgrom successfully showed that the above features can be explained by modifying Newton’s law of gravity as F=GMmr2μwhere μ is a function just added by Milgrom without a supporting theory behind and is assumed to have certain special properties to suit the purpose. In this paper, it is shown that when the attenuation of dark energy by the space medium is taken into account, Newton’s law of gravity gets modified with a correction term in it. This correction term surprisingly gives rise to the required properties of the function μ added by Milgrom to the existing conventional law of gravity. The work presented here therefore can be considered as a theoretical support for the successful phenomenological scheme proposed by Milgrom. 展开更多
关键词 dark Matter dark Energy MOND Alagar-Uma Mass formula Axioms for Space
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Deep-Dark-Net:一种基于生成对抗网络的导星相机暗流预测模型
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作者 曲伯桓 杨贺珺 +14 位作者 何宇轩 郭远昊 刘宇 曹子皇 齐朝祥 于涌 王培培 赵永恒 张勇 王淑青 栗剑 吕冠儒 曹兴华 向铭 邱虹云 《天文学进展》 CSCD 北大核心 2024年第4期683-697,共15页
暗流会影响图像质量、降低星像的信噪比,进而影响星像位置和流量测量的精度,因此需要在天文数据处理中准确估计并去除暗流。LAMOST导星图像处理的需求为:在无暗场图像情况下高精度处理历史导星图像数据,简化导星相机暗场图像拍摄的步骤... 暗流会影响图像质量、降低星像的信噪比,进而影响星像位置和流量测量的精度,因此需要在天文数据处理中准确估计并去除暗流。LAMOST导星图像处理的需求为:在无暗场图像情况下高精度处理历史导星图像数据,简化导星相机暗场图像拍摄的步骤,可以利用导星图像的特性反演和生成高精度可靠的暗场图像。利用LAMOST导星原始数据的特性,提出一种基于生成对抗网络模型来精确估计暗流的新方法——Deep-Dark-Net。该方法利用条件生成对抗网络,构建导星图像Overscan区域、Optical Black区域与对应的有效成像区域噪声之间的关联模型,从而通过这些区域反演和重构高精度暗场图像。实验表明:Deep-Dark-Net预测的暗流与真实暗流的符合度高于传统方法,满足了LAMOST望远镜导星图像处理对暗场图像的需求。该工作不仅为天文图像暗流的处理提供了一种新思路、新方法,也为深度学习技术在天文图像处理中的潜在价值和应用方向提供了重要的视角和示例。 展开更多
关键词 暗流 深度学习 条件生成对抗网络 Deep-dark-Net LAMOST
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Dynamical Dark Energy in Light of Cosmic Distance Measurements.Ⅱ.A Study Using Current Observations 被引量:1
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作者 Xiaoma Wang Gan Gu +2 位作者 Xiaoyong Mu Shuo Yuan Gong-Bo Zhao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第6期15-20,共6页
We extract key information on dark energy from current observations of BAO,OHD and H_(0),and find hints of dynamical behavior of dark energy.In particular,a dynamical dark energy model whose equation of state crosses-... We extract key information on dark energy from current observations of BAO,OHD and H_(0),and find hints of dynamical behavior of dark energy.In particular,a dynamical dark energy model whose equation of state crosses-1 is favored by observations.We also find that the Universe has started accelerating at a lower redshift than expected. 展开更多
关键词 COSMOLOGY (cosmology:)dark energy cosmology:observations
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Comparison of displacement damage effects on the dark signal in CMOS image sensors induced by CSNS back-n and XAPR neutrons 被引量:1
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作者 Yuan-Yuan Xue Zu-Jun Wang +3 位作者 Wu-Ying Ma Min-Bo Liu Bao-Ping He Shi-Long Gou 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第10期29-40,共12页
This study investigates the effects of displacement damage on the dark signal of a pinned photodiode CMOS image sensor(CIS)following irradiation with back-streaming white neutrons from white neutron sources at the Chi... This study investigates the effects of displacement damage on the dark signal of a pinned photodiode CMOS image sensor(CIS)following irradiation with back-streaming white neutrons from white neutron sources at the China spallation neutron source(CSNS)and Xi'an pulsed reactor(XAPR).The mean dark signal,dark signal non-uniformity(DSNU),dark signal distribution,and hot pixels of the CIS were compared between the CSNS back-n and XAPR neutron irradiations.The nonionizing energy loss and energy distribution of primary knock-on atoms in silicon,induced by neutrons,were calculated using the open-source package Geant4.An analysis combining experimental and simulation results showed a noticeable proportionality between the increase in the mean dark signal and the displacement damage dose(DDD).Additionally,neutron energies influence DSNU,dark signal distribution,and hot pixels.High neutron energies at the same DDD level may lead to pronounced dark signal non-uniformity and elevated hot pixel values. 展开更多
关键词 Displacement damage effects CMOS image sensor(CIS) CSNS back-n XAPR neutrons Geant4 dark signal non-uniformity(DSNU)
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Adding Dark Matter to the Standard Model 被引量:3
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作者 Bruce Hoeneisen 《International Journal of Astronomy and Astrophysics》 2021年第1期59-72,共14页
Detailed and redundant measurements of dark matter properties have recently become available. To describe the observations we consider scalar, vector and sterile neutrino dark matter models. A model with vector dark m... Detailed and redundant measurements of dark matter properties have recently become available. To describe the observations we consider scalar, vector and sterile neutrino dark matter models. A model with vector dark matter is consistent with all current observations. 展开更多
关键词 dark Matter Boson dark Matter dark Matter Theory dark Matter Model
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Dark Matter Search in Dwarf Irregular Galaxies with Ten Years of Data from the Ice Cube Neutrino Observatory
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作者 Yi-Fei Lü Ben-Yang Zhu +4 位作者 Rong-Lan Li Xue-Kang Guo Tian-Ci Liu Yong-Bo Huang Yun-Feng Liang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第3期75-82,共8页
Dwarf irregular galaxies(dIrrs),as rotationally supported systems,have more reliable J-factor measurements than dwarf spheroidal galaxies and have received attention as targets for dark matter detection in recent year... Dwarf irregular galaxies(dIrrs),as rotationally supported systems,have more reliable J-factor measurements than dwarf spheroidal galaxies and have received attention as targets for dark matter detection in recent years.In this paper,we use 10 yr of IceCube muon-track data and an unbinned maximum-likelihood-ratio method to search for neutrino signals beyond the background from the directions of seven dIrrs,aiming to detect neutrinos produced by heavy annihilation dark matter.We do not detect any significant signal.Based on such null results,we calculate the upper limits on the velocity-averaged annihilation cross section for 1 TeV–10 PeV dark matter.Our limits,although weaker than the strictest constraints in the literature in this mass range,are also a good complement to the existing results considering the more reliable J-factor measurements of dIrrs. 展开更多
关键词 (cosmology) dark matter-cosmology theory-galaxies DWARF
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Applying the Dark Target Aerosol Algorithm to MERSI-Ⅱ:Retrieval and Validation of Aerosol Optical Depth over the Ocean
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作者 Xin PEI Leiku YANG +4 位作者 Weiqian JI Shuang CHEN Xiaoqian CHENG Xiaofeng LU Hongtao WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第12期2446-2463,共18页
The Medium-Resolution Spectral Imager-Ⅱ(MERSI-Ⅱ)instrument aboard China’s Fengyun-3D satellite shares similarities with NASA’s Moderate Resolution Imaging Spectroradiometer(MODIS)sensor,enabling the retrieval of g... The Medium-Resolution Spectral Imager-Ⅱ(MERSI-Ⅱ)instrument aboard China’s Fengyun-3D satellite shares similarities with NASA’s Moderate Resolution Imaging Spectroradiometer(MODIS)sensor,enabling the retrieval of global aerosol optical depth(AOD).However,no officially released operational MERSI-Ⅱ aerosol products currently exist over the ocean.This study focuses on adapting the MODIS dark target(DT)ocean algorithm to the MERSI-Ⅱ sensor.A retrieval test is conducted on the 2019 MERSI-Ⅱ data over the global ocean,and the retrieved AODs are validated against ground-based measurements from the automatic Aerosol Robotic Network(AERONET)and the shipborne Maritime Aerosol Network(MAN).The operational MODIS DT aerosol products are also used for comparison purposes.The results show that MERSI-Ⅱ AOD granule retrievals are in good agreement with MODIS products,boasting high correlation coefficients(R)of up to 0.96 and consistent spatial distribution trends.Furthermore,the MERSI-Ⅱ retrievals perform well in comparison to AERONET and MAN measurements,with high R-values(>0.86).However,the low-value retrievals from MERSI-Ⅱ tend to be slightly overestimated compared to MODIS,despite both AODs displaying a positive bias.Notably,the monthly gridded AODs over the high latitudes of the northern and southern hemispheres suggest that MERSI-Ⅱ exhibits greater stability in space and time,effectively reducing unrealistically high-value noise in the MODIS products.These results illustrate that the MERSI-Ⅱ retrievals meet specific accuracy requirements by maintaining the algorithmic framework and most of the algorithmic assumptions,providing a crucial data supplement for aerosol studies and climate change. 展开更多
关键词 aerosol optical depth MERSI-Ⅱ MODIS dark target
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Design of hadronic calorimeter for DarkSHINE experiment
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作者 Zhen Wang Rui Yuan +18 位作者 Han-Qing Liu Jing Chen Xiang Chen Kim Siang Khaw Liang Li Shu Li Kun Liu Qi-Bin Liu Si-Yuan Song Tong Sun Xiao-Long Wang Yu-Feng Wang Hai-Jun Yang Jun-Hua Zhang Yu-Lei Zhang Zhi-Yu Zhao Chun-Xiang Zhu Xu-Liang Zhu Yi-Fan Zhu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第9期155-167,共13页
The sensitivity of the dark photon search through invisible decay final states in low-background experiments relies sig-nificantly on the neutron and muon veto efficiencies,which depend on the amount of material used ... The sensitivity of the dark photon search through invisible decay final states in low-background experiments relies sig-nificantly on the neutron and muon veto efficiencies,which depend on the amount of material used and the design of the detector geometry.This paper presents the optimized design of the hadronic calorimeter(HCAL)used in the DarkSHINE experiment,which is studied using a GEANT4-based simulation framework.The geometry is optimized by comparing a traditional design with uniform absorbers to one that uses different thicknesses at different locations on the detector,which enhances the efficiency of vetoing low-energy neutrons at the sub-GeV level.The overall size and total amount of material used in the HCAL are optimized to be lower,owing to the load and budget requirements,whereas the overall performance is studied to satisfy the physical objectives. 展开更多
关键词 Hadronic calorimeter GEANT4 simulation Neutron background Scintillation detector dark photon
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