scholarly journals Estimate of energy constituents of the universe in ΛCDM

2017 ◽  
Vol 95 (1) ◽  
pp. 21-24
Author(s):  
Jung-Jeng Huang ◽  
Meng-Jong Wang

We propose that the Hubble law can be viewed as the de Broglie relation on a cosmic scale. We show how the entropy of the Universe can be estimated in the ΛCDM model and its extended version, and how the quest for the maximal entropy leads to the energy constituents of the current Universe.

2021 ◽  
pp. 2150111
Author(s):  
Fei-Quan Tu ◽  
Bin Sun ◽  
Meng Wan ◽  
Qi-Hong Huang

Entropy is a key concept widely used in physics and other fields. At the same time, the meaning of entropy with different names and the relationship among them are confusing. In this paper, we discuss the relationship among the Clausius entropy, Boltzmann entropy and information entropy and further show that the three kinds of entropy are equivalent to each other to some extent. Moreover, we point out that the evolution of the universe is a process of entropy increment and life originates from the original low entropy of the universe. Finally, we discuss the evolution of the entire universe composed of the cosmological horizon and the space surrounded by it and interpret the entropy as a measure of information of all microstates corresponding to a certain macrostate. Under this explanation, the thermodynamic entropy and information entropy are unified and we can conclude that the sum of the entropy of horizon and the entropy of matter in the space surrounded by the horizon does not decrease with time if the second law of thermodynamics holds for the entire universe.


Author(s):  
Татьяна Юрьевна Сем

Статья посвящена мифологическому образу космического оленя в традиционной культуре тунгусо-маньчжуров. В работе рассматриваются материалы фольклора, шаманства, промысловых и календарных ритуалов, а также искусства. Впервые систематизированы материалы по всем тунгусо-маньчжурским народам. Образ космического оленя в фольклоре эвенов имеет наиболее близкие аналогии с амурскими народами, которые представляют его с рогами до небес. Он сохранился в сказочном фольклоре с мифологическими и эпическими элементами. В эвенском мифе образ оленя имеет космические масштабы: из тела его происходит земля и всё живущее на ней. У народов Амура образ оленя нашел отражение в космогенезе, отделении неба от земли. Своеобразие сюжета космической охоты характеризует общесибирскую мифологию, относящуюся к ранней истории. В ней наиболее ярко проявляется мотив смены старого и нового солнца, хода времени, смены времен года, календарь тунгусо-маньчжуров. В результате анализа автор пришел к выводу, что олень в тунгусо-маньчжурской традиции моделирует пространство и время Вселенной, характеризует образ солнца и хода времени. Космический олень является архетипичным символом культуры тунгусо-маньчжуров, сохранившим свое значение до настоящего времени в художественной культуре This article is devoted to the mythological image of cosmic deer in traditional Tungus-Manchu culture. It examines materials of folklore, shamanism, trade and calendar rituals as well as art and for the first time systematizes materials from all of the Tungus-Manchu peoples. The image of cosmic deer in the folklore of the Evens has its closest analogy in that of the Amur peoples, reflected in the image of a deer with horns reaching up to the sky. This image is preserved in fairytales with mythological and epic elements. In the Even myth, the image of a deer is on a cosmic scale, as the cosmos issues from its body. Among the Amur peoples, the image of a deer is also related to cosmogenesis, to the separation of the earth from the sky. The plot of a cosmic hunt is reflected in pan-Siberian mythology, dating back to the Bronze Age. It clearly illustrates the motif of the change of the old and new sun, the passage of time, the change of seasons, the Tungus-Manchu calendar. The author comes to the conclusion that deer in the Tungus-Manchu tradition, in depicting the image of the sun and the passage of time, model the space and time of the Universe. The cosmic deer is an archetypal symbol of Tungus-Manchu culture, which has retained its significance in artistic culture to the present day.


2011 ◽  
Vol 01 ◽  
pp. 228-233
Author(s):  
YUNGUI GONG

The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models. Remarkably, the growth rate can be approximated as Ωγ. We discuss the dependence of the growth index γ on the dimensionless matter energy density Ω for a more accurate approximation of the growth factor. The observational data are used to fit different models. The data strongly disfavor the Dvali-Gabadadze-Porrati model. For the ΛCDM model, we find that [Formula: see text]. For the Dvali-Gabadadze-Porrati model, we find that [Formula: see text].


Author(s):  
L Kazantzidis ◽  
H Koo ◽  
S Nesseris ◽  
L Perivolaropoulos ◽  
A Shafieloo

Abstract We search for possible deviations from the expectations of the concordance ΛCDM model in the expansion history of the Universe by analysing the Pantheon Type Ia Supernovae (SnIa) compilation along with its Monte Carlo simulations using redshift binning. We demonstrate that the redshift binned best fit ΛCDM matter density parameter Ω0m and the best fit effective absolute magnitude $\cal M$ oscillate about their full dataset best fit values with considerably large amplitudes. Using the full covariance matrix of the data taking into account systematic and statistical errors, we show that at the redshifts below z ≈ 0.5 such oscillations can only occur in 4 to 5% of the Monte Carlo simulations. While statistical fluctuations can be responsible for this apparent oscillation, we might have observed a hint for some behaviour beyond the expectations of the concordance model or a possible additional systematic in the data. If this apparent oscillation is not due to statistical or systematic effects, it could be due to either the presence of coherent inhomogeneities at low z or due to oscillations of a quintessence scalar field.


2014 ◽  
Vol 11 (02) ◽  
pp. 1460014 ◽  
Author(s):  
Winfried Zimdahl

Interactions inside the cosmological dark sector influence the cosmological dynamics. As a consequence, the future evolution of the Universe may be different from that predicted by the ΛCDM model. We review main features of several recently studied models with nongravitational couplings between dark matter and dark energy.


2006 ◽  
Vol 21 (25) ◽  
pp. 5151-5162 ◽  
Author(s):  
HOLGER B. NIELSEN ◽  
MASAO NINOMIYA

The universe is certainly not yet in a total thermodynamical equilibrium. Thus some law of special initial conditions is needed. A universe or a system imposed to behave periodically will then require "initial conditions." Those initial conditions will not look like the type we already have, which have been suffered the heat death. In other words, the required initial conditions should not have been obtained the maximal entropy — like a random state. The intrinsic periodicity successfully explains why entropy is not maximal but it fails, phenomenologically, in leading to a constant entropy.


2011 ◽  
Vol 03 ◽  
pp. 163-169
Author(s):  
M. NOVELLO

Recently a mechanism to generate mass from gravitational interaction, based on Mach principle, according to which the inertia of a body is a property of matter as well as of the background provided by the rest-of-the-universe was presented in Refs. 1, 2. In these papers such an idea was realized for scalar and spinor fields treating the rest-of-the-universe in its vacuum state. In the present paper, using an extended version of Mach principle, the same strategy will be applied to show how the Heisenberg-Nambu-Jona-Lasinio non-linear equation for fermions Ψ arises as a consequence of the gravitational interaction of Ψ with the rest-of-the-universe.


2010 ◽  
Vol 710 (2) ◽  
pp. 1825-1834 ◽  
Author(s):  
Chas A. Egan ◽  
Charles H. Lineweaver

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