宇宙暗能量的地理生物效应及对地球变暖的制约——低碳经济和暗能量

为了研究宇宙暗能量对地球的具体作用,在世界上首创用太阳黑子相对数作为取数建模的基础,用多年太阳黑子相对数的年变化去解密暗能量波,用多年地球气象信息的时空地理分布差异作为暗能量的密码本去解密暗能量的地理效应,还到野外实地考察。结果从地球气象信息的时空地理分布差异和太阳黑子相对数年变化的统计表及数学图像中发现了暗能量的地理效应,具体是温度效应、负压力效应和次生的自然灾害效应,在野外还发现了暗能量的生物效应,百年老树、千年古树对宇宙暗能量有指示作用。用数学、物理、天文、地理、生物和气象的基础理论第一次给出了暗能量的计算公式,明确了暗能量的本质和宇宙膨胀发生红移的根本原因,对低碳经济和宇宙暗能量的关系进行了初步分析。

2003世界十大科技成就

美国<科学>杂志近日评出了2003年世界十大科技成就.

2003年世界十大科技新闻

1、科学家破译4条人体染色体 2003年1月,法国基因测序中心科学家破译了人类第14号染色体的遗传密码。4月和6月,美国科学家又先后破译了人类第7号和Y染色体。

2003年世界科技新闻

用干细胞培育出卵细胞和精细胞法国和美国的科研人员于2003年5月初在《科学》杂志网络版上发表研究成果说,他们将老鼠胚胎干细胞转化成为具有性向的卵细胞。12月11日《自然》杂志网络版报道说,美国麻省白头生物医学研究所的乔治·达里和他的同事从雄性老鼠胚胎上取出干细胞,并将它们放置在空球中培养。然后再将空球中获得的类似精子的细胞注射进未受精的卵子中,获得了老鼠胚胎,其中1/5发育正常。

Nonequilibrium Thermodynamics of Dark Energy on Cosmic Apparent Horizon

In recent several years,some works have been done on cosmic thermodynamics.The apparent horizonwas regarded as the key characteristic supersurface where thermodynamics can be built on perfectly.However,if theirreversible process is considered,the proper position for building thermodynamics will not be the apparent horizonanymore.The new position is related to dark energy state equation and the irreversible process parameters.

Oscillating Flat FRW Dark Energy Dominated Cosmology from Periodic Functional Approach

I discuss the modification of Einstein＇s Theory of General Relativity based on a periodic functional approach. In this new approach, a corrected periodic gravitational coupling constant arises and plays the role of periodic damping term acting on the theory. It is found that it is achievable to have an oscillating universe dominated by dark energy and expanding aceeleratedly in time.

Dark Energy Accretion onto a Black Hole in an Expanding Universe

By using the solution describing a black hole embedded in the FLRW universe,we obtain the evolvingequation of the black hole mass expressed in terms of the cosmological parameters.The evolving equation indicates thatin the phantom dark energy universe the black hole mass becomes zero before the Big Rip is reached.

Dark Energy Model with Non-Minimal Coupling and Cosmological Constant Boundary

In this paper,we study a kind of dark energy models in the framework of the non-minimal coupling.With this kind of models,dark energy could cross the cosmological constant boundary,and at early time,dark energy could have 'tracking' behavior.

Holography,UV/IR Relation,Causal Entropy Bound,and Dark Energy

The constraint on the total energy in a given spatial region is given from holography by the mass of a black hole that just fits in that region, which leads to an UV/IR relation： the maximal energy density in that region is proportional to Mp^2/L^2, where Mp is the Planck mass and L is the spatial scale of that region under consideration. Assuming the maximal black hole in the universe is formed through gravitational collapse of perturbations in the universe, then the ＂Jeans＂ scale of the perturbations gives a causal connection scale RCC. For gravitational perturbations, RCC^-2= Max （H＋ 2H^2, -H） for a fiat universe. We study the cosmological dynamics of the corresponding vacuum energy density by choosing the causal connection scale as the IR cutoff in the UV/IR relation, in the cases of the vacuum energy density as an independently conserved energy component and an effective dynamical cosmological constant, respectively. It turns out that only the case with the choice RCC^-2 = H＋ 2H^2, could be consistent with the current cosmological observations when the vacuum density appears as an independently conserved energy component. In this case, the model is called holographic Ricci scalar dark energy model in the literature.

R^2 Correction and Its Implication of Present Cosmic Accelerating Behavior

In this work we show an model of the universe in which certain quadratic correction is considered. Our results indicate that the R2 term can act as the present impetus of cosmic acceleration, but there may be a future collapsing universe with this component damped. This model can also tolerate a negative cosmological constant ?, although there seems to be no need for a non-vanishing one. In our simplification, this curvature component has a stationary equation of state, which is similar to radiation. Unlike other dark energy models, this 'missing' energy has a negative density. Some details and effects on cold dark matter and Λ-relevant model have been discussed in the frame of curvature-squared gravity theories.

Large Number,Dark Matter,Dark Energy,and Superstructures in the Universe

Since there may exist dark matter particles ν and δ with mass - 10^-1 e V in the universe, the superstructures with a scale of 10^19 solar masses （large number A - 10^19） appeared during the era near and before the hydrogen recombination. Since there are superstructures in the universe, there may be no necessity for the existence of dark energy. For checking the superstructure in the universe by CMB anisotropy, we need to measure CMB angular power spectrum especially around ten degrees across the sky- in more details, While neutrino u is related to electroweak unification, the fourth stable elementary particle 6 may be related to strong-gravity unification, which suggests p ＋ p^- → n ＋ δ^- and that some new baryons appeared in the TeV region.

Dark energy and fate of the Universe

We explore the ultimate fate of the Universe by using a divergence-free parametrization for dark energy w（z）=w0＋wa, [In（2 ＋ z） / （1 ＋ z） - In 2] . Unlike the Chevallier-Polarski-Linder parametrization, this parametrization has well behaved, bounded behavior for both high redshifts and negative redshifts, and thus can genuinely cover many theoretical dark energy models. Alter constraining the parameter space of this parametrization by using the current cosmological observations, we find that, at the 95.4% confidence level, our Universe can still exist at least 16.7 Gyr before it ends in a big rip. Moreover, for the phantom energy dominated Universe, we find that a gravitationally bound system will be destroyed at a time t = P√2｜ 1 ＋ 3w（ 1）] / [6π] 1 ＋ w（-1）｜], where P is the period of a circular orbit around this system, before the big rip.

Interacting model of new agegraphic dark energy:observational constraints and age problem

Many dark energy models fail to pass the cosmic age test because of the old quasar APM 08279+5255 at redshift z=3.91,the ΛCDMmodel and holographic dark energy models being no exception.Inthis paper,we focus onthe topic of the age problem inthe new agegraphic dark energy(NADE)model.We determine the age of the universe in the NADE model by fitting the observational data,including type Ia supernovae(SNIa),baryon acoustic oscillations(BAO)and the cosmic microwave background(CMB).We find that the NADE model also faces the challenge of the age problem caused by the old quasar APM 08279+5255.In order to overcome such a difficulty,we consider the possible interaction between dark energy and dark matter.We show that this quasar can be successfully accommodated in the interacting new agegraphic dark energy(INADE)model at the 2σlevel under the current observational constraints.

Revisit of constraints on holographic dark energy:SNLS3 dataset with the effects of time-varying β and different light-curve fitters

Previous studies have shown that for the Supernova Legacy Survey three-year （SNLS3） data there is strong evidence for the redshifl- evolution of color-luminosity parameter β of type Ia supernovae （SN Ia）. In this paper, we explore the effects of varying β on the cosmological constraints of holographic dark energy （HDE） model. In addition to the SNLS3 data, we also use Planck distance prior data of cosmic microwave background （CMB）, as well as galaxy clustering （GC） data extracted from Sloan Digital Sky Survey （SDSS） data release 7 and Baryon Oscillation Spectroscopic Survey （BOSS）. We find that, for the both cases of using SN data alone and using SN＋CMB＋GC data, involving an additional parameter of β can reduce χ^2 by - 36; this shows that β deviates from a constant at 6σ- confidence levels. Adopting SN＋CMB＋GC data, we find that compared to the constant β case, varying β yields a larger fractional matter density Ωm0 and a smaller reduced Hubble constant h; moreover, varying β significantly increases the value of HDE model parameter c, leading to c ≈ 0.8, consistent with the constraint results obtained before Planck. These results indicate that the evolution of β should be taken into account seriously in the cosmological fits. In addition, we find that relative to the differences between the constant β and varying β（z） cases, the effects of different light-curve fitters on parameter estimation are very small.

Cosmological evolution of quintessence with a sign-changing interaction in dark sector

Dark energy and dark matter are only indirectly measured though their gravitational effects.It is possibie that there is some direct,non-gravitational interaction between DE and DM,which can be used to solve(or,at least alleviate)several important theoretical problems.In the present work,by analysing the cosmological dynamical system with a dark-sector interaction which changes its sign during the cosmological evolution,we find a scaling attractor to help to alleviate the cosmic-coincidence problem.This result shows that this interaction can bring new features to the cosmology.

Constrains on f(T) gravity with the strong gravitational lensing data

Strong lensing is an effective way to probing the properties of dark energy.In this paper,we use the strong lensing data to constrain the f(T)theory,which is a new modified gravity to explain the present accelerating cosmic expansion without the need of dark energy.In our discussion,the CMB and BAO data are also added to constrain model parameters tightly and three different f(T)models are studied.We find that strong lensing has an important role on constraining f(T)models,and once the CMB+BAO data is added,a tighter constraint is obtained.However,the consistency of our result with what is obtained from SNIa+CMB+BAO is actually model-dependent.

Reconstruction of Scalar Field Dark Energy Models in Kaluza-Klein Universe

This paper is devoted to study the modified holographic dark energy model by taking its different aspects in the t/at Kaiuza-Klein universe. We construct the equation of state parameter which evolutes the universe from quintessence region towards the vacuum. It is found that the modified holographic model exhibits instability against small perturbations in the early epoch of the universe but becomes stable in the later times. We also develop its correspondence with some scalar field dark energy models. It is interesting to mention here that ail the results are consistent with the present observations.

Modified Holographic Ricci Dark Energy in Chameleon Brans–Dicke Cosmology and Its Thermodynamic Consequence

The objective of this paper is to discuss the Chameleon Brans–Dicke gravity with non-minimally matter coupling of scalar field. We take modified Holographic Ricci dark energy model in this gravity with its energy density in interaction with energy density of cold dark matter. We assume power-law ansatz for scale factor and scalar field to discuss potential as well as coupling functions in the evolving universe. These reconstructed functions are plotted versus scalar field and time for different values of power component of scale factor n. We observe that potential and coupling functions represent increasing behavior, in particular, consistent results for a specific value of n. Finally, we have examined validity of the generalized second law of thermodynamics and we have observed its validity for all values of n.

Agegraphic Dark Energy with the Sign-Changeable Interaction in Non-Flat Universe

In this paper,we investigate the agegraphic dark energy(ADE) model by including the sign-changeable interaction between ADE and dark matter in non-flat universe.The interaction Q can change its sign from Q < 0 to Q > 0 as the universe expands.This indicates that at first dark matter decays to ADE,and then ADE decays to dark matter.We study the dynamical behavior of the model by using the phase-plane analysis.It is shown numerically that the coupling constant β plays an important role in the evolution of the universe.The equation of state(Eo S) of ADE with the sign-changeable interaction is more likely to cross the phantom divide w_d =-1 from top to bottom with the increasing of the |β|.Whereas in ADE model with usual interaction,wd can cross the phantom divide from bottom to top.We also find that our model is consistent with the observational data.

Effects of Anisotropy on Scalar Field Ghost Dark Energy and the Non-Equilibrium Thermodynamics in Fractal Cosmology

Since the fractal cosmology has been created in early universe, therefore their models were mostly isotropic. The majority of previous studies had been based on FRW universe, while in the early universe, the best model for describing fractal cosmology is actually the anisotropic universe. Therefore in this work, by assuming the anisotropic universe, the cosmological implications of ghost and generalized ghost dark energy models with dark matter in fractal cosmology has been discussed. Moreover, the different kinds of dark energy models such as quintessence and tachyon field, with the generalized ghost dark energy in fractal universe has been investigated. In addition, we have reconstructed the Hubble parameter, H, the energy density, p, the deceleration parameter, q, the equations of state parameter, wD, for both ghost and generalized ghost dark energy models. This correspondence allows us to reconstruct the potential and the dynamics of a fractal canonical scalar field according to the evolution of generalized ghost dark energy density. Eventually, thermodynamics of the cosmological apparent horizon in fractal cosmology was investigated and the validity of the Generalized second law of thermodynamics （GSLT） have been examined in an anisotropic universe. The results show the influence of the anisotropy on the OSLT of thermodynamics in a fractal cosmology.