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A Solution to the Cosmological Constant Problem in Two Time Dimensions
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作者 Christoph Köhn 《Journal of High Energy Physics, Gravitation and Cosmology》 2020年第4期640-655,共16页
For the last hundred years, the existence and the value of the cosmological constant Λ has been a great enigma. So far, any theoretical model has failed to predict the value of Λ by several orders of magnitude. We h... For the last hundred years, the existence and the value of the cosmological constant Λ has been a great enigma. So far, any theoretical model has failed to predict the value of Λ by several orders of magnitude. We here offer a solution to the cosmological constant problem by extending the Einstein-Friedmann equations by one additional time dimension. Solving these equations, we find that the Universe is flat on a global scale and that the cosmological constant lies between 10<sup>-90</sup> m<sup>-2</sup> and 10<sup>-51</sup> m<sup>-2</sup> which is in range observed by experiments. It also proposes a mean to explain the Planck length and to mitigate the singularity at the Big Bang. 展开更多
关键词 Two Time DIMENSIONS Planck Length Cosmological constant problem Curvature of the Universe
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A New Strategy for Solving Two Cosmological Constant Problems in Hadron Physics
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作者 Thomas L. Wilson 《Journal of Modern Physics》 2013年第5期686-703,共18页
A new approach to solving two of the cosmological constant problems (CCPs) is proposed by introducing the Abbott-Deser (AD) method for defining Killing charges in asymptotic de Sitter space as the only consistent mean... A new approach to solving two of the cosmological constant problems (CCPs) is proposed by introducing the Abbott-Deser (AD) method for defining Killing charges in asymptotic de Sitter space as the only consistent means for defining the ground-state vacuum for the CCP. That granted, Einstein gravity will also need to be modified at short-distance nuclear scales, using instead a nonminimally coupled scalar-tensor theory of gravitation that provides for the existence of QCD’s two-phase vacuum having two different zero-point energy states as a function of temperature. Einstein gravity alone cannot accomplish this. The scalar field will be taken from bag theory in hadron physics, and the origin of the bag constant B is accounted for by gravity’s CC as B—noting that the Higgs mechanism does not account for either the curved-space origin of λ or the mass of composite hadrons. A small Hubble-scale graviton mass mg^10-33eV naturally appears external to the hadron bag, induced by λ≠0. This mass is unobservable and gravitationally gauge-dependent. It is shown to be related to the cosmological event horizon in asymptotic de Sitter space. 展开更多
关键词 COSMOLOGICAL constant problem Vacuum ENERGY Density HADRON PHYSICS ASYMPTOTIC de SITTER Space Zero-Point ENERGY
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The Solution Cosmological Constant Problem
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作者 Jaykov Foukzon Elena Men’kova Alexander Potapov 《Journal of Modern Physics》 2019年第7期729-794,共66页
The cosmological constant problem arises because the magnitude of vacuum energy density predicted by the Quantum Field Theory is about 120 orders of magnitude larger then the value implied by cosmological observations... The cosmological constant problem arises because the magnitude of vacuum energy density predicted by the Quantum Field Theory is about 120 orders of magnitude larger then the value implied by cosmological observations of accelerating cosmic expansion. We pointed out that the fractal nature of the quantum space-time with negative Hausdorff-Colombeau dimensions can resolve this tension. The canonical Quantum Field Theory is widely believed to break down at some fundamental high-energy cutoff and therefore the quantum fluctuations in the vacuum can be treated classically seriously only up to this high-energy cutoff. In this paper we argue that the Quantum Field Theory in fractal space-time with negative Hausdorff-Colombeau dimensions gives high-energy cutoff on natural way. We argue that there exists hidden physical mechanism which cancels divergences in canonical QED4, QCD4, Higher-Derivative-Quantum gravity, etc. In fact we argue that corresponding supermassive Pauli-Villars ghost fields really exist. It means that there exists the ghost-driven acceleration of the universe hidden in cosmological constant. In order to obtain the desired physical result we apply the canonical Pauli-Villars regularization up to &Lambda;*. This would fit in the observed value of the dark energy needed to explain the accelerated expansion of the universe if we choose highly symmetric masses distribution between standard matter and ghost matter below the scale &Lambda;*, i.e., The small value of the cosmological constant is explained by tiny violation of the symmetry between standard matter and ghost matter. Dark matter nature is also explained using a common origin of the dark energy and dark matter phenomena. 展开更多
关键词 COSMOLOGICAL constant problem QUANTUM Field Theory Vacuum Energy Density QUANTUM Space-Time Hausdorff-Colombeau Dimension QUANTUM Fluctuations High-Energy CUTOFF CANONICAL Pauli-Villars Regularization Universe
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Oscillating Spacetime: The Foundation of the Universe
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作者 John A. Macken 《Journal of Modern Physics》 2024年第8期1097-1143,共47页
In this article, spacetime is modeled as a quantum mechanical sonic medium consisting of Planck length oscillations at Planck frequency. Planck length-time oscillations give spacetime its physical constants of c, G an... In this article, spacetime is modeled as a quantum mechanical sonic medium consisting of Planck length oscillations at Planck frequency. Planck length-time oscillations give spacetime its physical constants of c, G and ħ. Oscillating spacetime is proposed to be the single universal field that generates and unifies everything in the universe. The 17 fields of quantum field theory are modeled as lower frequency resonances of oscillating spacetime. A model of an electron is proposed to be a rotating soliton wave in this medium. An electron appears to have wave-particle duality even though it is fundamentally a quantized wave. This soliton wave can momentarily be smaller than a proton in a high energy collision or can have a relatively large volume of an atom’s orbital wave function. Finding an electron causes it to undergo a superluminal collapse to a smaller wave size. This gives an electron its particle-like properties when detected. The proposed wave-based electron model is tested and shown to have an electron’s approximate energy, de Broglie wave properties and undetectable volume. Most important, this electron model is shown to also generate an electron’s electrostatic and gravitational forces. The gravitational properties are derived from the nonlinearity of this medium. When an electron’s gravitational and electrostatic forces are modeled as distortions of soliton waves, the equations become very simple, and a clear connection emerges between these forces. For example, the gravitational force between two Planck masses equals the electrostatic force between two Planck charges. Both force magnitudes equal ħc/r2. 展开更多
关键词 Unification of Forces Electron Model Cosmological constant problem Foundation of Physics Aether
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一类华林-哥德巴赫方程的小素数解问题
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作者 高改芸 刘志新 《纯粹数学与应用数学》 2024年第3期450-464,共15页
华林-哥德巴赫方程的小素数解问题是堆垒素数论研究领域的重要研究课题,历来备受解析数论学者关注.本文研究一类满足必要条件的不等次幂华林-哥德巴赫方程的小素数解问题.利用标准的Hardy-Littlewood圆法和先进的Davenport方法,结合素... 华林-哥德巴赫方程的小素数解问题是堆垒素数论研究领域的重要研究课题,历来备受解析数论学者关注.本文研究一类满足必要条件的不等次幂华林-哥德巴赫方程的小素数解问题.利用标准的Hardy-Littlewood圆法和先进的Davenport方法,结合素变数三角和估计的最新成果及更加有效的Hölder不等式,得到该方程小素数解的更好上界,改进已有的研究结果. 展开更多
关键词 华林-哥德巴赫问题 素数 Baker常数 Davenport方法
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一类Kirchhoff双相问题的常符号解
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作者 姚迪 储昌木 熊明燕 《宁夏师范学院学报》 2024年第4期32-39,共8页
在双相椭圆问题中,利用截断技术和变分方法研究一类涉及退化情形的Kirchhoff双相问题,证明该类问题一个正符号解和一个负符号解的存在性,将双相问题的结果推广到退化和非退化的Kirchhoff双相情形.
关键词 Kirchhoff双相问题 截断技术 变分方法 常符号解
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Simultaneous estimation of aerosol optical constants and size distribution from angular light-scattering measurement signals 被引量:3
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作者 Zhen-Zong He Dong Liang +1 位作者 Jun-Kui Mao Xing-Si Han 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第5期564-572,共9页
The angular light-scattering measurement(ALSM) method combined with an improved artificial bee colony algorithm is introduced to determine aerosol optical constants and aerosol size distribution(ASD) simultaneousl... The angular light-scattering measurement(ALSM) method combined with an improved artificial bee colony algorithm is introduced to determine aerosol optical constants and aerosol size distribution(ASD) simultaneously. Meanwhile, an optimized selection principle of the ALSM signals based on the sensitivity analysis and principle component analysis(PCA)is proposed to improve the accuracy of the retrieval results. The sensitivity analysis of the ALSM signals to the optical constants or characteristic parameters in the ASD is studied first to find the optimized selection region of measurement angles. Then, the PCA is adopted to select the optimized measurement angles within the optimized selection region obtained by sensitivity analysis. The investigation reveals that, compared with random selection measurement angles, the optimized selection measurement angles can provide more useful measurement information to ensure the retrieval accuracy. Finally,the aerosol optical constants and the ASDs are reconstructed simultaneously. The results show that the retrieval accuracy of refractive indices is better than that of absorption indices, while the characteristic parameters in ASDs have similar retrieval accuracy. Moreover, the retrieval accuracy in studying L-N distribution is a little better than that in studying Gamma distribution for the difference of corresponding correlation coefficient matrixes of the ALSM signals. All the results confirm that the proposed technique is an effective and reliable technique in estimating the aerosol optical constants and ASD simultaneously. 展开更多
关键词 angular light-scattering measurement method aerosol optical constants aerosol size distribution inverse radiation problem
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Linearized Equations of General Relativity and the Problem of Reduction to the Newton Theory
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作者 Valery V. Vasiliev Leonid V. Fedorov 《Journal of Modern Physics》 2020年第2期221-236,共16页
The paper is concerned with the problem of reduction of the general relativity theory to the Newton gravitation theory for a gravitation field with relatively low intensity. This problem is traditionally solved on the... The paper is concerned with the problem of reduction of the general relativity theory to the Newton gravitation theory for a gravitation field with relatively low intensity. This problem is traditionally solved on the basis of linearized equations of general relativity which, being matched to the Newton theory equations, allow us to link the classical gravitation constant with the constant entering the general relativity equations. Analysis of the linearized general relativity equations shows that it can be done only for empty space in which the energy tensor is zero. In solids, the set of linearized general relativity equations is not consistent and is not reduced to the Newton theory equations. Specific features of the problem are demonstrated with the spherically symmetric static problem of general relativity which has the closed-form solution. 展开更多
关键词 General RELATIVITY GRAVITATION constant Linearized EQUATIONS Spherically Symmetric problem
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中学体育教学落实“教会、勤练、常赛”存在的问题与解决对策 被引量:1
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作者 王建明 孙大伟 《辽宁师专学报(自然科学版)》 2023年第1期95-98,共4页
为实现中学体育享受乐趣、增强体质、健全人格、锤炼意志“四位一体”的教学目标,分析中学体育教学中落实“教会、勤练、常赛”存在的问题,并针对性地提出正确理解体育教学与体育课堂教学的关系,全面实施“教会、勤练、常赛”政策,精准... 为实现中学体育享受乐趣、增强体质、健全人格、锤炼意志“四位一体”的教学目标,分析中学体育教学中落实“教会、勤练、常赛”存在的问题,并针对性地提出正确理解体育教学与体育课堂教学的关系,全面实施“教会、勤练、常赛”政策,精准掌控“会、勤、常”程度等对策,为体育教师有效开展教学提供理论参考. 展开更多
关键词 体育教学 教会、勤练、常赛 问题 对策
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冶金化学动力学研究中应注意的几个问题 被引量:9
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作者 孙召明 赵中伟 《稀有金属与硬质合金》 CAS CSCD 2001年第3期27-29,33,共4页
根据有关文献资料 ,对冶金化学动力学研究与应用中容易忽视的几个问题作了分析 ,指出了问题的症结所在 ,在此基础上提出了研究冶金化学动力学时应注意的几个问题。
关键词 冶金化学动力学 反应速度常数 阿仑尼乌斯活化能 机械活化
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基于混合遗传算法的混凝土大坝力学参数反演 被引量:13
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作者 李守巨 刘迎曦 +3 位作者 陈昌林 李正国 何翔 周圆 《大连理工大学学报》 EI CAS CSCD 北大核心 2004年第2期195-199,共5页
将混凝土大坝和岩石基础的力学参数识别反问题作为优化问题处理,然后采用混合遗传算法求解可准确地确定岩体的力学参数.基于观测的混凝土大坝坝顶水平位移,建立了识别混凝土大坝和岩石基础力学参数的数值方法.为解决简单遗传算法的早熟... 将混凝土大坝和岩石基础的力学参数识别反问题作为优化问题处理,然后采用混合遗传算法求解可准确地确定岩体的力学参数.基于观测的混凝土大坝坝顶水平位移,建立了识别混凝土大坝和岩石基础力学参数的数值方法.为解决简单遗传算法的早熟问题,将遗传算法与模拟退火算法相结合,提出了基于混合遗传算法的混凝土大坝力学参数反演方法.丰满混凝土大坝实际工程应用表明,根据参数反演结果预报大坝在不同水位条件下的水平位移具有较高的精度. 展开更多
关键词 混合遗传算法 混凝土大坝 力学参数识别 模拟退火算法 混合优化
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具L2有界不确定性系统常值调节问题的鲁棒最优解 被引量:2
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作者 陈善本 张福恩 +1 位作者 张铨 吴林 《宇航学报》 EI CSCD 北大核心 1994年第2期35-40,53,共7页
本文考虑具L2有界不确定性系统的常值调节问题,利用“最坏干扰”下的“最优控制”思想,将此问题描述为Maxmin线性二次跟踪指标下的最优控制问题,便可将其归入H∞控制理论所描述的一类鲁棒最优化问题,因此,一定意义下,本... 本文考虑具L2有界不确定性系统的常值调节问题,利用“最坏干扰”下的“最优控制”思想,将此问题描述为Maxmin线性二次跟踪指标下的最优控制问题,便可将其归入H∞控制理论所描述的一类鲁棒最优化问题,因此,一定意义下,本文可以认为是给出了相应一类H∞问题的时域解法。 展开更多
关键词 鲁棒最优控制 常值调节 控制系统
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考虑互相关干扰的GPS信号捕获门限设定方法 被引量:4
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作者 刘杨 秦红磊 金天 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2011年第3期268-273,共6页
传统GPS卫星信号捕获门限设定方法在互相关干扰情况下存在较大虚警概率,所以无法捕获弱信号.针对该问题进行分析,在此基础上提出一种针对多颗能量不同卫星同时存在情况下的信号检测模型和概率模型.信号检测模型在相关积分非相干累加基... 传统GPS卫星信号捕获门限设定方法在互相关干扰情况下存在较大虚警概率,所以无法捕获弱信号.针对该问题进行分析,在此基础上提出一种针对多颗能量不同卫星同时存在情况下的信号检测模型和概率模型.信号检测模型在相关积分非相干累加基础上引入双门限多次检测,由于在考虑噪声的同时也考虑了互相关干扰对弱信号捕获的影响,其概率模型为非中心χ2分布.在原有的恒虚警门限检测方法基础上,提出考虑强信号互相关干扰对微弱信号检测影响情况下的门限计算方法作为新的门限上限,而将原有的门限计算方法作为门限的下限.在此基础上提出强、弱卫星信号共存时的检测思路,即先用门限上限检测强信号并进行互相关干扰消除处理,再用门限下限判断是否有弱信号存在.采用仿真数据和实际数据针对考虑互相关干扰的门限上限进行实验,并和原有门限方法进行比较,证明在强、弱信号共存情况下原有门限无法检测出卫星信号,而新的门限设定方法可以正常工作,并具有较高的检测概率和较低的虚警概率. 展开更多
关键词 微弱信号捕获 远近效应 恒虚警准则 门限设定
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三维常数势边界元中的精确积分 被引量:2
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作者 赵振峰 石宪章 申长雨 《应用力学学报》 EI CAS CSCD 北大核心 2005年第4期589-592,共4页
对三维问题边界元方法中应用最广泛的常数边界元的积分提出一种精确积分方法。借助于一个假想的闭合曲面,将特定的势场应用于边界积分方程,发现对于三维问题,常数势项的积分可以化作球面三角型的面积计算,而导数项的积分则可在平面域用... 对三维问题边界元方法中应用最广泛的常数边界元的积分提出一种精确积分方法。借助于一个假想的闭合曲面,将特定的势场应用于边界积分方程,发现对于三维问题,常数势项的积分可以化作球面三角型的面积计算,而导数项的积分则可在平面域用极坐标进行。本文方法结果精确,公式简单,同一计算公式可以用来计算非奇异、几乎奇异和奇异积分,统一了积分算法。 展开更多
关键词 边界元法 三维问题 常数势 精确积分 奇异积分
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基于时域信息的粒径分布及光学常数重建 被引量:1
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作者 任亚涛 齐宏 +1 位作者 张晓罗 阮立明 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2017年第11期2193-2198,共6页
准确地测量颗粒系粒径分布与光学常数对于准确地预测相关介质内的辐射传输过程具有重要意义。采用一种改进的烟花算法同时反演了颗粒系粒径分布与光学常数。通过测量不同波长的激光辐照下,一维颗粒系的不同角度的时域透射信号,并结合改... 准确地测量颗粒系粒径分布与光学常数对于准确地预测相关介质内的辐射传输过程具有重要意义。采用一种改进的烟花算法同时反演了颗粒系粒径分布与光学常数。通过测量不同波长的激光辐照下,一维颗粒系的不同角度的时域透射信号,并结合改进的烟花算法对其光学常数以及粒径分布进行反演。通过对3种常见的粒径分布函数进行测试发现,使用本文提出的改进的烟花算法结合相应的物性测量方法可以准确得到颗粒系粒径分布与光学常数。 展开更多
关键词 烟花算法 粒径分布 光学常数 反问题 时域辐射传输
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几类特殊几何体的迷向常数 被引量:2
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作者 吴力荣 何斌吾 《上海大学学报(自然科学版)》 CAS CSCD 北大核心 2007年第1期41-46,共6页
设K是Rn中体积为1,质心在原点的凸体,LK是它的迷向常数,寻找LK的上确界,是Banach空间局部理论(现代几何分析)中著名的未解决问题.目前最好的上界估计是LK<cn1/4logn,它是由Bourgain证明的.最近,何斌吾、冷岗松又证明了当r1Bn2 K r2Bn... 设K是Rn中体积为1,质心在原点的凸体,LK是它的迷向常数,寻找LK的上确界,是Banach空间局部理论(现代几何分析)中著名的未解决问题.目前最好的上界估计是LK<cn1/4logn,它是由Bourgain证明的.最近,何斌吾、冷岗松又证明了当r1Bn2 K r2Bn2(r1≥1/2,r2≤n/2)时,LK≤1/(2 3),并猜测在对称几何体中以超立方体的迷向常数为最大,在非对称几何体中以单形的迷向常数为最大.给出了在三维空间中全部正多面体的迷向常数的数值,从而说明这一猜测对三维空间中的正多面体是正确的. 展开更多
关键词 凸体 迷向体 迷向常数 Bourgain问题
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非线性四阶多点边值问题的正解存在性 被引量:3
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作者 孔令彬 辛彤 《东北石油大学学报》 CAS 北大核心 2014年第4期97-102,12,共6页
研究一类含参数的非线性四阶多点边值问题,当参数属于一定范围时,利用常数变易法求得与边值问题等价的函数,并对它进行上下界估计,同时利用锥不动点定理,证明该四阶边值问题正解的存在性.
关键词 四阶边值问题 常数变易法 锥定理 正解
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Gronwall不等式及其应用 被引量:3
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作者 魏章志 梅宇 陈浩 《宿州师专学报》 2003年第3期65-66,共2页
本文介绍了Gronwall不等式及其推广,并将其应用于一阶常微分方程Cauchy初值问题的研究。
关键词 GRONWALL不等式 Cauchy初值问题 LIPSCHITZ常数
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用有限元分析和DICM确定纸浆模塑材料弹性常数的逆问题 被引量:10
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作者 平幼妹 余本农 +2 位作者 计宏伟 邵文泉 滕立军 《包装工程》 CAS CSCD 北大核心 2006年第1期24-27,共4页
用有限元法分析纸浆模塑包装结构,需要事先确定纸浆模塑材料的弹性常数。基于纸浆模塑薄壁圆锥筒的压缩试验,讨论了可以利用有限元分析和数字相关测量方法(D ICM)来识别纸浆模塑材料弹性常数的逆问题。
关键词 逆问题 纸浆模塑 弹性常数 有限元分析 数字相关测量方法
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非线性四阶多点边值问题的正解 被引量:1
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作者 赵冬霞 张玲 田淑杰 《哈尔滨师范大学自然科学学报》 CAS 2017年第5期9-14,共6页
研究一类含参数的非线性四阶多点边值问题,当参数属于一定范围时,利用常数变易法求得与边值问题等价的Green函数,并对其上下界进行估计,利用锥定理,证明四阶边值问题正解的存在性.
关键词 四阶边值问题 常数变易法 正解
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