International Astronomy and Astrophysics Research Journal <p style="text-align: justify;"><strong>International Astronomy and Astrophysics Research Journal</strong>&nbsp;aims to publish high-quality papers (<a href="">Click here for Types of paper</a>) in all areas of Astronomy and Astrophysics. By not excluding papers based on novelty, this journal facilitates the research and wishes to publish papers as long as they are technically correct and scientifically motivated. The journal also encourages the submission of useful reports of negative results. This is a quality controlled, OPEN peer-reviewed, open-access INTERNATIONAL journal.</p> en-US (International Astronomy and Astrophysics Research Journal) (International Astronomy and Astrophysics Research Journal) Tue, 06 Dec 2022 06:18:16 +0000 OJS 60 The Distances between, and the Formation Times of, the Galaxies <p>Since the James Webspace Telescope, JWST came into operation during the first half of the year 2022, cosmological times and distances have been reported, that reach more than 13 billion years and light years. These cosmological data are of a much higher order of magnitude than those handled in traditional astronomy. When analyzing the information published by Naidu, R. P. et al. and other authors, about the Galaxy Glass-z13, GZ, recently discovered by the JWSP, where a redshift, z = 13.1, of the captured signals was measured; it is concluded that GZ is being seen in the form and position in which it was 13,500 million years ago. During this time the light traveled a distance, Dv, equivalent to 13.5 billion light years, for now, been detected in the Milky Way, MW. Next, it is explained what this data means and how it is possible to calculate: 1). The distance, Da, the two galaxies (MW and GZ) are now, 2). The distance, Do, at which the said galaxies were located 13,500 million years ago, 3). The distance, Dm, that each of the galaxies moved, towards opposite directions, 4). The scale factor, a(t), and the relation of the commoving distance, to the proper distance, and 5). The comparison of the above-mentioned cosmological distances, with other local astronomical distances such as the distance between the MW and the Andromeda galaxy and also the distance between the Earth and a planet, but that of the closest star to the Sun, the planet Proxima Centauri b, described by Davis, N. K. S. These comparisons are intended to get a better idea of the orders of magnitude that cosmological distances and astronomical distances mean.</p> Cruz Gomez, M. Javier ##submission.copyrightStatement## Mon, 05 Dec 2022 00:00:00 +0000 The Significance of Shear Stress in Cosmology <p>The concept of shear stress forms a fundamental base for meteorology and oceanography, which is the heritage of classical physics.&nbsp; In this paper, we show by well understood physical reasoning that it is also fundamental to cosmology although this link has not been previously recognised.&nbsp;&nbsp; The key physical model is that of the sea surface where two fluids (air and water) of high density contrast interact giving rise to a constant shear stress layer and wave breaking.</p> <p>In cosmology, we show that two analogous, equal and opposite stress layers, due respectively to the formation of galaxies on the large scale and to their destruction by black holes on the small scale, constitute the physical model for the Universe, in which the mean shear stress is zero. The consequences of this condition for the expanding Universe are shown in a simple model.&nbsp; Two comparative images are also presented which illustrate the similarity between stress fields observed in a laboratory experiment and in the cosmos.</p> John A. T. Bye ##submission.copyrightStatement## Wed, 21 Dec 2022 00:00:00 +0000 Spatially Closed FRW Model Leads to Einstein’s Universe with Cosmological Constant <p>Einstein revisited his equations and altered by introducing something known as a universal constant. Einstein's 1917 concept has been with us ever since in various variants and incarnations, including the broader concept of 'Dark Energy’. Einstein’s field equation has been studying under the assumption of a power law time variation of the expansion factor. The Hubble’s parameter and distance modulus in our descended model are in good concordance with recent data of astrophysical observations under appropriate conditions. Theoretically, the cosmological constant Λ and the density parameter<em>&nbsp; p</em> are determined using dynamical tests like as density and velocity profiles around clusters and virialization. This paper, we discuss and briefly other classes of models that have a close relationship with the Freidmann models, and these are models derived from modified Einstein equations containing the cosmological constant. Thus the cosmological constant is not any old value but rather simply the inverse of the scale factor squared, where the scale factor is a fixed value in static closed universe. Ultimately we derived to describe the final radius of a virialized cluster, in which a repulsive cosmological constant lambda (Λ) gives a smaller value. Based on the results, two scenarios for the universe are proposed, one with a huge proportion of nonbaryonic matter and a zero cosmological constant, and the other with all matter being baryonic. The cosmological constant is added to save inflation and build up a static universe model.</p> A. S. M. Mohiul Islam, Md. Habibur Rahman ##submission.copyrightStatement## Fri, 30 Dec 2022 00:00:00 +0000