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| viXra.org > Astrophysics > 2508 |
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[9] viXra:2508.0178 [pdf] submitted on 2025-08-30 02:14:45
Authors: Kiyoung Kim
Comments: 8 Pages.
Magnetic field reversal is not a unique property of the Sun. Tau Boötis A, a star located 51 light-years from Earth, with one exoplanet, has been undergoing magnetic field reversals that have been observed since 2008. Many solar-type stars outside our solar system have shown indirect signs of magnetic activity, suggesting possible reversals. While a few of them have been directly observed, their magnetic field changes include shifting magnetic poles. The magnetic field reversal of Tau Boötis A is interpreted to be driven by the interaction with its exoplanet, Tau Boötis Ab, similar to the interaction between the Sun, Jupiter, and Saturn. For solar-type stars with empirical data, the correlation of star’s magnetic activity cycle to its rotation period is compared with another possible correlation of magnetic activity cycle to the rotation period, radius, and B-field intensity of the star—together.
Category: Astrophysics
[8] viXra:2508.0177 [pdf] submitted on 2025-08-30 23:05:08
Authors: Thorsten Hilker
Comments: 16 Pages. In German (Note by viXra Admin: Please submit article written with AI assistance to ai.viXra.org)
This work presents an approach to extending classical gravitational dynamics by modeling tidal forces between rotating celestial bodies as a viscous, velocity-dependent coupling. Using concrete examples (Earth—Moon, Earth—Sun, Mars—Phobos), it is shown that this coupling can explain observed distance changes. The application of this concept demonstrates the evolution of galactic rotation curves in a simulation without dark matter, thus offering an introduction to a potentially fundamental complement to Newtonian physics.
Category: Astrophysics
[7] viXra:2508.0153 [pdf] replaced on 2026-02-27 01:30:05
Authors: Manuel Abarca Hernandez
Comments: 26 Pages.
The purpose of this study is to demonstrate that the NFW DM density profile is consistent with the velocity decay law characterized by a radial dependence of r^-0.25 within the halo regions of MW, M31 and other fives galaxies outside the LG. The velocity decay law was derived from a novel framework known as the DM by Quantum Gravitation theory, hereafter DMbQG. This theory proposes that DM arises from the propagation of the gravitational field through an as-yet-unknown quantum gravitational phenomenon.As the NFW method have been validated extensively is crucial to examine if the new DMbQG theory produces a virial mass indistinguishable from NFW predictions.At the core of the DMbQG framework lies the direct mass formula, which yields the total enclosed mass within a sphere of radius r. The total mass depends on the parameter a^2, where a is the proportionality constant in the velocity decay law.There is a dual approaches to calculate the parameter a : (i) directly from the galactic rotation curve in the halo region, (ii) indirectly from the virial mass and radius derived via the NFW model and using the direct mass. In practice, the total galactic virial mass can be estimated by adding the baryonic mass to the virial DM mass obtained through the NFW method.Consequently, if the parameter a derived from the rotation curve coincides with the value of a obtained using the direct mass formula with the total mass inferred from the NFW formalism, the central thesis of this work is validated.The structure of this paper is as follows: In Chapter 2, the parameter a is calculated for the MW using rotation curve datasets from two independent authors. Chapter 3 introduces the NFW formalism and its principal expressions. Chapter 4 presents the derivation of a^2 from the direct mass formula using the virial mass obtained through the NFW method. In Chapter 5, the parameter a obtained through both approaches is compared for the MW using two independent datasets. Chapter 6 mirrors this analysis for the M31 galaxy, again employing two distinct datasets. Chapters 7, 8 and 9 study the compatibility of NFW method with the decay law velocity in five galaxies outside the Local Group, being four galaxies selected from the SPARC project. Across these seven galaxies, inside and outside the Local Group, the results provide strong support for the velocity decay law into the halo as universal.
Category: Astrophysics
[6] viXra:2508.0132 [pdf] submitted on 2025-08-20 21:41:45
Authors: Li Yuan
Comments: 21 Pages.
This paper is an introductory outline published for a series of discussions on dark matter and dark energy. Dark energy and dark matter are the two differences between cosmic observations and the calculations of existing technological systems. It is divided into ten specific questions.Following the ideas of the ten questions, through calculation and Mathematical deduction, the veil of dark energy and dark matter can be gradually unveiled. It is shown that dark energy and dark matter are the accumulated results of miscalculations caused by a series of historical limitations of mankind.
Category: Astrophysics
[5] viXra:2508.0066 [pdf] submitted on 2025-08-10 01:16:42
Authors: Leonardo Rubino
Comments: 36 Pages.
Calculation of the deflection of light by the Sun - three methods.
Category: Astrophysics
[4] viXra:2508.0046 [pdf] replaced on 2025-08-11 00:57:19
Authors: E. P. J. de Haas
Comments: 40 Pages. (Note by viXra Admin: For the last time, please submit article written with AI assistance to ai.viXra.org)
We present a novel method for estimating the cosmic expansion rate $H_z$ at high redshift ($z approx 2$--$10$) using the internal dynamics and morphology of nearby galaxies—without relying on direct redshift—distance measurements. The approach models rotation curves of systems showing a clear structural transition between a central bar (interpreted as a fossil spiral) and an outer spiral disk. Within a dual-Lagrangian framework, these nested structures are assigned separate dynamical regimes, enabling $H_z$ to be extracted from the mass $M$ and emph{critical radius} $r_c$ of the proto-bar region. The critical radius is defined locally by the condition $v_H(r_c) = v_{m esc}(r_c)$, which yields a emph{local critical density} $ho_c propto H_z^2$. When this purely local relation is mapped onto cosmic time using the $Lambda$CDM matter-era scaling $H(t) propto t^{-1}$, it reproduces the universal $ho_c propto t^{-2}$ law. Applying the method to seventeen galaxies, and scanning early bulge mass fractions from $0.2%$ to $20%$ of today’s $M_{m bulge}$, we find that the $0.5%$—$5%$ range best matches the $Lambda$CDM timeline for disk—spiral onset. A refined backward-time minimization, incorporating a power-law bulge growth model, further narrows the plausible onset window to $0.4$—$1.8$~Gyr after the Big Bang. This technique complements high-redshift probes such as emph{JWST} imaging and CMB extrapolations, offering a new class of local, dynamical constraints on the early universe. If validated and applied to large rotation-curve samples, it could yield hundreds to thousands of independent $H_z$ determinations, refining both the cosmic expansion history and the baryonic structure formation timeline.
Category: Astrophysics
[3] viXra:2508.0015 [pdf] submitted on 2025-08-04 20:09:15
Authors: Andrew Martin
Comments: 23 Pages. (Note by viXra Admin: Please cite listed scientific references and submit article written with AI assistance to ai.viXra.org)
This paper proposes a two part reinterpretation of cosmological redshift and spectral line broadening, based on classical wave behavior rather than spacetime expansion.First: Redshift arises from the medium itself. Light does not travel through a vacuum. Intergalactic space is filled with tenuous plasma that interacts more readily with higher frequencies. As light travels across vast distances, high frequency components are scattered or absorbed more often than lower ones. What reaches us is biased toward longer wavelengths. This is survivorship, not metric expansion.Second: Coherence loss is a direct result of geometry in three dimensions. As wavefronts expand, their surface area grows, and each observer samples a smaller portion of the full wave. If the emitter has any instability in frequency, timing, or angle, this leads to phase variation across the observed wave. The result is line broadening and signal smearing. These effects do not require stretching of space or time. They are a natural outcome of how expanding waves behave in a structured field.Together, these effects explain the two most persistent cosmological signatures, redshift and time dilation, without invoking expansion at all. Light doesn’t just stretch. It is filtered and smeared.
Category: Astrophysics
[2] viXra:2508.0011 [pdf] submitted on 2025-08-03 23:20:17
Authors: Clark M. Thomas
Comments: 3 Pages.
Lambda Dark Matter (LDM) envisions dark matter as awavelength (λ) phenomenon. How particles and energy waves are defined influences how and if LDM could be a valuable part of an emerging Theory of Everything.
Category: Astrophysics
[1] viXra:2508.0010 [pdf] submitted on 2025-08-03 23:52:21
Authors: Rama Kalaga
Comments: 24 Pages. (Note by viXra Admin: Please list author name after article title and submit article written with AI assistance to ai.viXra.org)
This paper investigates the galaxy rotation curve problem while validating dark matter asthe primary solution. Standard Newtonian Dynamics show that stellar speeds decrease withradial distance from the central area of galaxies. Since the early 20th century, physicists have found flat rotation curves during observations, which demonstrate unidentified mass in galaxies that they have termed dark matter. The primary focus of this investigation delves into how welldark matter functions as an answer to resolve the galaxy rotation curve issue. The study evaluatesthe accuracy of dark matter models, particularly the NFW and Burkert profiles, by comparingmathematical model-generated rotation curves with experimental data obtained from the Gaiaand APOGEE databases. The first outcome shows that standard baryonic matter explanations donot duplicate observed rotation patterns, particularly in the Milky Way. The combination of NFWand Burkert profiles produces significant improvements in the match while analyzing older datapoints. Recently acquired data with elevated accuracy shows departures from current dark mattertheory to describe galaxy rotation curves. Current data requires evaluating alternative scientificmodels, including Modified Newtonian Dynamics (MOND) and revised models of dark matterdistributions. This paper indicates that dark matter remains the primary theory for unexplained observations, yet details that high-quality new datasets demand improved theoretical models. The research advances the ongoing astrophysical discussions about how galaxies function and shape dark matter patterns and potential modern physics theories beyond existing theoretical boundaries.
Category: Astrophysics
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