Large Scale Fundamental Interactions in the Universe

The author of this paper once attempted to propose a unified framework for gauge fields based on the mathematical and physical picture of the principal fiber bundle: that is, to believe that our universe may have more fundamental interactions than the four, and these fundamental gauge fields are only components on the bottom manifold (i.e. our universe) projected by a unified gauge potential of the principal fiber bundle manifold;these components can satisfy the transformation of gauge potential, or even be transformed from one basic interaction gauge potential to another basic interaction gauge potential, and can be summarized into a unified equation, namely the generalized gauge equation expression, corresponding to gauge transformation invariance;so the invariance of gauge transformation is a necessary condition for unified field theory, and the four (or more) fundamental interaction fields of the universe are unified in a unified gauge field defined by the connection on the principal fiber bundle. In this paper, the author continues to propose a model of large-scale (gravitational) fundamental interactions in the universe based on the mathematical and physical picture of the principal fiber bundle, attempting to explain that dark matter and dark energy are merely reflections of these gravitational fundamental interactions that deviate in intensity from the gravitational fundamental interactions of the solar system at galaxy scales or some cosmic scales which are much larger than the solar system. All these “gravitational” fundamental interactions originate from the unified gauge field of the universe, namely the connection or curvature on the principal fiber bundle. These interactions are their projected representations on the bottom manifold (i.e. our universe) by different cross-sections (gauge transformations). These projection representations of the universe certainly are described by the generalized gauge equation or curvature similarity equation, and under the guidance of curvature gauge transformation factors, oscillate and evolve between the curvatures 1→0→-1→0→1 of the universe.

The Gravitational Constant as the Function of the Cosmic Scale

This paper uses the cosmic evolution picture constructed by the principal and associated fiber bundles and, with the help of gauge invariance, systematically proposes the γfactor theory that the Newton’s law of universal gravitation and the cosmological constant of Einstein’s equation must be corrected in the large-scale space-time structure of the universe. That is, it is found that the calculated value of Newton’s universal gravitation in space-time above the scale of galaxies must be multiplied by 1/γto be consistent with the measured value, and the cosmological constant of Einstein’s equation is no longer a constant but a function that increases with the increase of the scale of cosmic regions. Therefore, the cyclic hypothesis of cosmic evolution is proposed, and it is further found that the gravitational constant that people think is natural is not a constant but a function that changes with the scale of cosmic regions. Therefore, the reason for the dark matter and dark energy hypothesis may be that the gravitational constant is a variable. The existence of actual dark matter and dark energy may be just an illusory hypothesis, and their origin comes from the understanding that the gravitational constant is constant.

Exists Gravitation Inverse Matter

Existence of gravitation inverse matter in finite space is shown inevitable. As an example, direction of gravitation of rest mass of electron is opposite to that of positron. That is, electron and positron are gravitationally repulsive to each other. The physical space has previously been shown of finite extent. Therefore, if gravitation normal matter is found prevailing in the physical space then, according to the law of mass/charge balance in finite space, the Universe, i.e., the physical space and all that it contains/confines, must be a shell-structured black hole in a higher dimensional space.

Dark Matter, Dark Energy, and Occam’s Razor

Even though dark matter and dark energy have long been accepted as being of fundamental importance in cosmology, in this paper, we will present arguments to show that neither is necessary. Instead, the phenomena they are thought to be responsible for are consequences of a vacuum whose curvature varies with time. We will focus on three phenomena that are thought to require the existence of dark energy and dark matter. The first is the idea that dark energy is responsible for the observed accelerating expansion of the universe. We will show instead that with time-varying curvature, Einstein’s equations demand such an acceleration without reference to dark or any other form of energy. Turning to dark matter, it is supposedly required to explain the observed constant velocity profile of the stars making up the disks of spiral galaxies and to explain the strong gravitational lensing observed in galaxy clusters. We will show, however, that both phenomena can again be understood in terms of the vacuum and its curvature. In the former case, we will show that galaxies exist within a rotating volume of the vacuum and that this leads directly to the observed constant velocity profiles. In the latter case, gradients of the vacuum curvature serving as a varying index of refraction are responsible. Using numerical results from our new model of nucleosynthesis, we estimate the degree of bending to expect and find that the results are in accord with observation. Our new model very naturally explains the phenomena attributed to dark matter and dark energy and since neither has been observed after several decades of looking, Occam’s razor tells us that neither exists.

Taiji data challenge for exploring gravitational wave universe

The direct observation of gravitational waves(GWs)opens a new window for exploring new physics from quanta to cosmos and provides a new tool for probing the evolution of universe.GWs detection in space covers a broad spectrum ranging over more than four orders of magnitude and enables us to study rich physical and astronomical phenomena.Taiji is a proposed space-based gravitational wave(GW)detection mission that will be launched in the 2030s.Taiji will be exposed to numerous overlapping and persistent GW signals buried in the foreground and background,posing various data analysis challenges.In order to empower potential scientific discoveries,the Mock Laser Interferometer Space Antenna(LISA)data challenge and the LISA data challenge(LDC)were developed.While LDC provides a baseline framework,the first LDC needs to be updated with more realistic simulations and adjusted detector responses for Taiji’s constellation.In this paper,we review the scientific objectives and the roadmap for Taiji,as well as the technical difficulties in data analysis and the data generation strategy,and present the associated data challenges.In contrast to LDC,we utilize second-order Keplerian orbit and second-generation time delay interferometry techniques.Additionally,we employ a new model for the extreme-mass-ratio inspiral waveform and stochastic GW background spectrum,which enables us to test general relativity and measure the non-Gaussianity of curvature perturbations.Furthermore,we present a comprehensive showcase of parameter estimation using a toy dataset.This showcase not only demonstrates the scientific potential of the Taiji data challenge(TDC)but also serves to validate the effectiveness of the pipeline.As the first data challenge for Taiji,we aim to build an open ground for data analysis related to Taiji sources and sciences.More details can be found on the official website(taiji-tdc.ictp-ap.org).

A Different Cosmology—Thoughts from Outside the Box

In this paper, we present a new cosmology based on the idea of a universe dominated by vacuum energy with time-varying curvature. In this model, the universe began with an exponential Plank era inflation before transitioning to a spacetime described by Einstein’s equations. While no explicit model of the Plank era is yet known, we do establish a number of properties that the vacuum of that time must have exhibited. In particular, we show that structures came into existence during that inflation that were later responsible for all cosmic structures. A new solution of Einstein’s equations incorporating time-varying curvature is presented which predicts that the scaling was initially power law with a parameter of y=1/2 before transitioning to an exponential acceleration of the present-day scaling. A formula relating the curvature to the vacuum energy density is also a part of the solution. A non-conventional model of nucleosynthesis provides a solution for the matter/antimatter asymmetry problem and a non-standard origin of the CMB. The CMB power spectrum is shown to be a consequence of uncertainties embedded during the initial inflation and the existence of superclusters. Using Einstein’s equations, we show that so-called dark matter is, in fact, vacuum energy. A number of other issues are discussed.

Global sensitivity and uncertainty analysis of the VIP ecosystem model with an expanded soil nitrogen module for winter wheat-summer maize rotation system in the North China Plain

Accurately simulating the soil nitrogen(N)cycle is crucial for assessing food security and resource utilization efficiency.The accuracy of model predictions relies heavily on model parameterization.The sensitivity and uncertainty of the simulations of soil N cycle of winter wheat-summer maize rotation system in the North China Plain(NCP)to the parameters were analyzed.First,the N module in the Vegetation Interface Processes(VIP)model was expanded to capture the dynamics of soil N cycle calibrated with field measurements in three ecological stations from 2000 to 2015.Second,the Morris and Sobol algorithms were adopted to identify the sensitive parameters that impact soil nitrate stock,denitrification rate,and ammonia volatilization rate.Finally,the shuffled complex evolution developed at the University of Arizona(SCE-UA)algorithm was used to optimize the selected sensitive parameters to improve prediction accuracy.The results showed that the sensitive parameters related to soil nitrate stock included the potential nitrification rate,Michaelis constant,microbial C/N ratio,and slow humus C/N ratio,the sensitive parameters related to denitrification rate were the potential denitrification rate,Michaelis constant,and N2 O production rate,and the sensitive parameters related to ammonia volatilization rate included the coefficient of ammonia volatilization exchange and potential nitrification rate.Based on the optimized parameters,prediction efficiency was notably increased with the highest coefficient of determination being approximately 0.8.Moreover,the average relative interval length at the 95% confidence level for soil nitrate stock,denitrification rate,and ammonia volatilization rate were 11.92,0.008,and 4.26,respectively,and the percentages of coverage of the measured values in the 95% confidence interval were 68%,86%,and 92%,respectively.By identifying sensitive parameters related to soil N,the expanded VIP model optimized by the SCE-UA algorithm can effectively simulate the dynamics of soil nitrate stock,denitrification rate,and ammonia volatilization rate in the NCP.

The Rise of Xiaoshuo as a Literary Concept： Lu Xun and the Question of ＂Fiction＂ in Chinese Literature

Originally derived from historical and philosophical writings, xiaoshuo is the modem Chinese term for fictional work of any length. However, how this term came to be used to translate the Western concepts of ＂fiction＂ and ＂novel＂ is a question that remains to be fully explored. This paper focuses on Lu Xun＇s seminal work Zhongguo xiaoshuo shilue （A brief history of Chinese fiction; 1925） so as to investigate the ways in which the Western concept of fiction is built into Lu Xun＇s historicization of xiaoshuo. I argue that Lu Xun＇s articulation of xiaoshuo is distinguished by his emphasis on both the term＇s universality and its ＂Chinese-ness.＂