Cosmological Issues Research Articles

Fluctuation-dissipation relation in cosmic microwave background

We study the fluctuation-dissipation relation for sound waves in the cosmic microwave background (CMB), employing effective field theory (EFT) for fluctuating hydrodynamics.Treating sound waves as the linear response to thermal radiation, we establish the fluctuation-dissipation relation within a cosmological framework.While dissipation is elucidated in established linear cosmological perturbation theory, the standard Boltzmann theory overlooks the associated noise, possibly contributing to inconsistencies in Lambda Cold Dark Matter (ΛCDM) cosmology. This paper employs EFT for fluctuating hydrodynamics in cosmological perturbation theory, deriving sound wave noise.Notably, the long-time limit of the noise spectrum is independent of viscosity details, resembling a Brownian motion bounded in a harmonic potential.The net energy transfer between the sound wave system and the radiation environment reaches a balance within Hubble time, suggesting the thermal equilibrium of the sound waves themselves.The induced density power spectrum is characterized as white noise dependent on the inverse of the entropy density, which is negligibly small on the CMB scale. The energy density of the entire sound wave system scales as a -4, akin to radiation. While the numerical factor is not determined in the present calculation, the back reaction of the sound wave system to the background radiation may not be negligible, serving as a potential source for various fitting issues in ΛCDM cosmology.

The Editorial of the T-Consciousness Cosmology Special Issue

Through presenting the Spherical Cosmos model, T-Consciousness Cosmology comprises a collection of theories that examine and analyze topics, such as the origin of the universe, its nature, the manner of its evolution, its fate, and hundreds of other theories in the special issues of T-Consciousness Cosmology.

Model-independent Way to Determine the Hubble Constant and the Curvature from the Phase Shift of Gravitational Waves with DECIGO

In this Letter, we propose a model-independent method to determine the Hubble constant and curvature simultaneously by taking advantage of the possibilities of future spaceborne gravitational-wave detector DECIGO in combination with the radio quasars as standard rulers. Similarly to the redshift drift in the electromagnetic domain, accelerating expansion of the Universe causes a characteristic phase correction to the gravitational waveform detectable by DECIGO. Hence, one would be able to extract the Hubble parameter H(z). This could be used to recover a distance–redshift relation supported by the data not relying on any specific cosmological model. Assuming the FLRW metric and using intermediate-luminosity radio quasars as standard rulers, one achieves an interesting opportunity to directly assess the H 0 and Ω k parameters. To test this method, we simulated a set of acceleration parameters achievable by future DECIGO. Based on the existing sample of 120 intermediate-luminosity radio quasars calibrated as standard rulers, we simulated much bigger samples of such standard rulers possible to obtain with very long baseline interferometry (VLBI). In the case of (N = 100) of radio quasars, which is the size of the currently available sample, the precision of the cosmological parameters determined would be σH0=2.74 km s−1 Mpc−1 and σΩk=0.175 . In the optimistic scenario (N = 1000) achievable by VLBI, the precision of H 0 would be improved to 1%, which is comparable to the result of σH0=0.54 km s−1 Mpc−1 from Planck 2018 TT, TE, EE+lowE+lensing data, and the precision of Ω k would be 0.050. Our results demonstrate that such combined analysis, possible in the future, could be helpful in solving the current cosmological issues concerning the Hubble tension and cosmic curvature tension.

Correlation between acne and insulin resistance; experience from central India.

Acne is a common dermatological condition primarily seen in teenage and adolescent patients and is a major concern for cosmological issues. Along with environmental factors, the proliferation of basal keratinocytes in the sebaceous-pilosebaceous unit, abnormal desquamation of follicular corneocytes, and metabolic abnormalities play a significant role in the pathogenesis of acne development. To study the causal relation between acne vulgaris and insulin resistance by calculating Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) and identify the relation between insulin resistance and the severity of acne. This was a retrospective study, where the data of patients with persistent Acne Vulgaris who were referred to the Endocrine department for evaluation of the hormonal and metabolic causes for acne vulgaris were analysed. The patient's clinical records were evaluated in whom there was no significant hormonal or metabolic abnormality identified known to cause persistent acne were included after proper consent and HOMA-IR was calculated. Of several patients with persistent acne, 150 patients were included in our study with the male-to-female ratio was 23:27. The mean age of patients was 33.2 years. The mean HOMA-IR in our acne patients was 1.62 ranging from 0.9-3.7. Sixty four (42.67%) patients had HOMA-IR more than 2.0, thereby suggesting insulin resistance. Our study suggests the prevalence of insulin resistance in 42.67% of patients with acne, thereby providing the possibility of use of insulin modifiers as an adjunct acne treatment and stratifying the possible risk of metabolic syndrome in patients with acne. Also recommended is the control of dietary factors and lifestyle modification for the management of acne with insulin resistance.

A NEW METHOD OF INVESTIGATION OF THE ORIENTATION OF GALAXIES IN CLUSTERS IN LACK OF INFORMATION ABOUT THEIR MORPHOLOGICAL TYPES

The problem of the formation of structures in the universe is one of the most important issues of modern extragalactic astronomy and cosmology. The tool enabling the verification of a particular formation scenario is analysis the spatial orientation of the galaxies from deprojection of their images. Obtaining correct analysis results obliges to take into account the fact that galaxies are oblate spheroids with the real axis ratio depending on the morphological type, which, however, is not given in most of the currently available astronomical data. According to the approach used in the new method of investigation, on the basis of estimated frequencies of occurrence of given morphological types, obtained using sufficiently numerous observational data, simulations are performed, which enable to recognize new angle distributions used in orientation studies. These distributions already contain information on the frequency of the appearance of galaxies of particular morphological types in clusters, allowing for more accurate results of the statistical tests carried out during the analysis. The method is an extension of results developed in Godłowski 2012 and Pajowska et al. 2019.

Indigenous Knowledge in Esan Proverbs of Edo State Nigeria

The Esan people are an ethnicity in the Edo state of Nigeria. Their language and culture are a subset of the larger Edo ethnic group in Nigeria. A close study of the Esan indigenous knowledge and culture reveals that the appeal of the Esan folk proverbs is in their eclectic nature because of their portrayal of diverse issues in the Esan cosmology and belief system, ranging from folk art to traditional health care beliefs and practices. This finding suggests that the subject of Esan proverbs deserves some scholarly attention. This article, therefore, examines the nature of Esan proverbs even as they perform their didactic and pedagogical functions in contemporary Esan parlance. By its nature, this study adopted a combination of research approaches, which included content analysis, library searches, and ethnographic methods such as interviews and observations. In the ethnographic study of a specific Nigerian with a focus on its proverbs, this paper’s research light shall beam over the five local government areas (LGAs) populated by the Esan people in the Edo State of Nigeria. Apart from its potential for insightful scholarship, the significance of this study on Esan proverbs also lies in the fact that inquiries into the indigenous knowledge system (IKS) portray folk proverbs as veritable windows into the culture and essence of a people. Indigenous knowledge has much more impact on contemporary society than people know.

On the dynamics of a dark sector coupling

Interacting dark energy models may play a crucial role in explaining several important observational issues in modern cosmology and also may provide a solution to current cosmological tensions. Since the phenomenology of the dark sector could be extremely rich, one should not restrict the interacting models to have a coupling parameter which is constant in cosmic time, rather allow for its dynamical behaviour, as it is common practice in the literature when dealing with other dark energy properties, as the dark energy equation of state. We present here a compendium of the current cosmological constraints on a large variety of interacting models, investigating scenarios where the coupling parameter of the interaction function and the dark energy equation of state can be either constant or dynamical. For the most general schemes, in which both the coupling parameter of the interaction function and the dark energy equation of state are dynamical, we find 95% CL evidence for a dark energy component at early times and slightly milder evidence for a dynamical dark coupling for the most complete observational data set exploited here, which includes CMB, BAO and Supernova Ia measurements. Interestingly, there are some cases where a dark energy component different from the cosmological constant case at early times together with a coupling different from zero today, can alleviate both the H0 and S8 tension for the full dataset combination considered here. Due to the energy exchange among the dark sectors, the current values of the matter energy density and of the clustering parameter σ8 are shifted from their ΛCDM-like values. This fact makes future surveys, especially those focused on weak lensing measurements, unique tools to test the nature and the couplings of the dark energy sector.

Quantum gravity, the cosmological constant, and parity transformation

One of the leading issues in quantum field theory and cosmology is the mismatch between the observed and calculated values for the cosmological constant in Einstein's field equations of up to 120 orders of magnitude. In this paper, we discuss new methods to potentially bridge this chasm using the generalized uncertainty principle (GUP). We find that if quantum gravity GUP models are the solution to this puzzle, then it may require the gravitationally modified position operator undergoes a parity transformation at high energies.

Exploring modifications to FLRW cosmology with general entropy and thermodynamics: A new approach

The investigation of modifications to the FLRW cosmology resulting from the consideration of a general entropy for the cosmological apparent horizon is the subject of this study. Building upon the work of Nojiri and colleagues in 2022, who introduced a class of generalized entropies with four parameters capable of converging to familiar entropies and addressing specific cosmological issues, our research explores the impact of correcting the entropy on the energy-momentum tensor of the cosmic fluid from the outset. Our calculations demonstrate that, by employing a correction function f(ρ) to modify the energy-momentum density tensor, the entropic area law (Bekenstein-Hawking entropy) can still be regarded as a general entropy. The construction of the function f(ρ) is facilitated through considerations of the thermodynamics associated with the apparent horizon. Additionally, we investigate the first and second laws of thermodynamics within this framework and illustrate how the limitations imposed on the equation of state of the cosmic fluid can be resolved through the incorporation of this correction function. Finally, we compute cosmography parameters to analyze the kinematics of the universe, with particular attention given to the notable influence of the correction function f(ρ) on these parameters. This paper provides valuable insights into the application of general entropies to the apparent horizon of the universe.

Energy conditions of traversable wormhole in the deformed f(R) gravitational model

One of the most important issues in cosmology is the study of a series of hypothetical objects called wormholes. Recently, researchers have studied these hypothetical objects under different conditions. In this paper, we aim to evaluate the traversable wormhole according to a modified [Formula: see text] gravitational model, specifically [Formula: see text], from the perspective of two essential functions in wormhole structure: shape and redshift function. These hypothetical objects can solve Einstein’s equations by tolerating the violation of null energy conditions (NEC). With respect to these concepts, we examine various energy conditions such as the NEC, weak energy condition (WEC), dominant energy condition (DEC) and strong energy condition (SEC) using radial pressure, tangential pressure and energy density obtained from the wormhole equations. Finally, we evaluate different energy conditions by plotting some figures and checking for satisfaction or violation. We will analyze the results and present the conclusions in tables.

Evidence of a decreasing trend for the Hubble constant

The current discrepancy between the Hubble constant, H0, derived from the local distance ladder and from the cosmic microwave background is one of the most crucial issues in cosmology, as it may possibly indicate unknown systematics or new physics. Here, we present a novel non-parametric method to estimate the Hubble constant as a function of redshift. We establish independent estimates of the evolution of Hubble constant by diagonalizing the covariance matrix. From type Ia supernovae, baryon acoustic oscillation data and the observed Hubble parameter data, a decreasing trend in the Hubble constant with a significance of a 5.6σ confidence level is found. At low redshift, its value is dramatically consistent with that measured from the local distance ladder and it drops to the value measured from the cosmic microwave background at high redshift. Our results may relieve the Hubble tension, with a preference for recent solutions, especially with respect to novel physics.

The Meaning of Human Life in the Context of the Evolution of the Universe: V. I. Vernadsky and P. Teilhard De Chardin

Abstract The authors of the paper reflect on the meaning of human life in relation to the universe, drawing on scientific knowledge about evolution and highlighting interconnections between anthropological and cosmological issues. The paper considers the inspiring ideas of V. I. Vernadsky and P. Teilhard de Chardin, especially their understanding of the noosphere. Despite Vernadsky’s and Teilhard’s contrasting interpretations of the noosphere, the authors conclude that both consider the meaning of human life to be about self-improvement and taking responsibility for future evolution.

Dark matter fermions: from linear to non-linear structure formation

The transition from linear to non-linear structure formation in cosmology is here studied from the point of view of the thermodynamics of self-gravitating fermions. We start by reviewing the principle of maximum entropy production through which such a fermionic system can relax towards spherical equilibrium states able to explain the dark matter (DM) in galaxies. We then analyze the stability, lifetime and morphology of the above configurations, and show that the most general DM profile develops a compact core governed by degeneracy pressure, which is surrounded by an extended halo. For DM particles which are in the range of $\mathcal{O}$(10--100) keV, we apply this theory to the case of the Milky Way, and show that the compact DM-core explains the dynamics of all the best resolved S-cluster stars orbiting SgrA *, without the need of assuming a central black hole (BH). Further consequences of this theory regarding open issues in cosmology are outlined, including the problem of formation of supermassive BHs in the early Universe.

Review: Legions of Pigs in the Early Medieval West, by Jamie Kreiner

In Legions of Pigs, Jamie Kreiner uses pigs as a lens through which she examines the early medieval West from North Africa to the British Isles and Scandinavia. Pigs are unique among the medieval domestic mammals. Unlike cattle, sheep, goats, horses, and donkeys, pigs do not produce secondary products that can be extracted from live animals, such as milk, wool, hair, traction, and transport. Pigs produce meat and other primary products, such as skin and bone, that can be accessed only when a pig is slaughtered. Pigs are also biologically and behaviorally distinct from the other early medieval farm animals. They are smart and will eat almost anything, but they can be dangerous and require careful management so that they do not destroy agricultural fields and other aspects of the landscape and the built environment. Using pigs as a focal point, the chapters in this volume explore worldview and cosmology, agriculture and ecology, social organization, and religion across the late antique and early medieval West.The research that went into this volume is meticulous, and the scope of the volume is impressive. The geographic range includes North Africa, Iberia, and the Norse colonies in Iceland and Greenland, in addition to the more well-studied regions of early medieval western Europe, such as the British Isles and Francia. Kreiner is a documentary historian, but I was impressed with her knowledgeable and creative use of the archaeological and zooarchaeological data on early medieval animal husbandry and agriculture. She draws on zooarchaeological data to show how the relative importance of pigs in early medieval societies varied across both time and space. For example, while pigs played an important role in many early medieval societies, recent archaeological research has shown that they were introduced to Iceland at the beginning of the Norse settlement, but they declined rapidly thereafter, possible due to the damage that they did to the fragile environment.Kreiner begins by describing pigs as animals that provided meat, a commodity that early medieval people wanted, but also as animals that were intelligent and required management. She then links these animals to broader issues of early medieval cosmology and worldview. Her third chapter focuses on pigs in the early medieval landscape. This is where her interdisciplinary skills really shine. Kreiner draws on archaeological data to show how pig husbandry varied across the early medieval world as a result environmental differences and the choices that early medieval farmers and landowners made. She then explores the complex laws and negotiations that governed access to pannage for pigs in the woodlands during the acorn season. Kreiner’s historical data complement the archaeological evidence to provide a rich picture of early medieval pig management. Her next chapter explores the relationships between pigs and humans, ranging from the role of swineherds to the social context of pork consumption. Her final chapter explores the relationship between pigs and Christianity.The volume is extensively documented with over 50 pages of notes and a wide-ranging bibliography. It is also well illustrated with 32 pages of color plates, 7 useful maps that show the locations of the sites and regions discussed in the volume, and many black-and-white in-text figures.Early medieval studies are by their nature interdisciplinary, drawing on evidence from historical records, archaeological excavations, and art historical studies. This volume is one of the most creatively interdisciplinary volumes that I have had the pleasure to read. Kreiner has produced a truly multispecies history, using the relationships between pigs and people to explore the agrarian, social, and cultural history of the early medieval period. As a result, this book will be of great interest to early medievalists who work with texts and material culture, as well as scholars who work in interdisciplinary fields such as historical ecology and animal studies. I will use this book when I teach both medieval archaeology and zooarchaeology. My archaeology students will appreciate Kreiner’s careful and critical use of archaeological and zooarchaeological data, and they will benefit from her use of pigs as a lens to explore broader issues of early medieval cosmology, religion, and social organization. These issues are nearly impossible to study on the basis of archaeological data alone. The volume is clearly and engagingly written, and I recommend it in the highest possible terms.

Conserved relativistic Ertel’s current generating the vortical and thermodynamic aspects of space–time

Motivated by Aoki et al.’s recent research on conserved charges and entropy current, we reinvestigated the conservation of relativistic Ertel’s current, which has received little attention outside the field of geophysical fluid dynamics. Ertel’s charge is an important indicator of the correlation between vortex vectors and entropy gradient fields in Earth’s meridional heat transport. We first show that in the generalized Hamiltonian structure of baroclinic fluids, the duality between the total energy and the Casimir as a function of Ertel’s charge plays an important role in the nonrelativistic case. Then, by extending the result to relativistic cases, we show that this finding has far-reaching implications not only for space–time issues in cosmology but also for the foundation of quantum field theory. An especially important finding is that, as an unreported dual form of the Einstein field equation, we identify a special equation satisfied not only by the vortex tensor field generated by the conserved charge but also by the Weyl tensor in interpreting the physical nature of the metric tensor [Formula: see text], which appears in the cosmological term [Formula: see text].

Athena synergies in the multi-messenger and transient universe

In this paper we explore the scientific synergies between Athena and some of the key multi-messenger facilities that should be operative concurrently with Athena. These facilities include LIGO A+, Advanced Virgo+ and future detectors for ground-based observation of gravitational waves (GW), LISA for space-based observations of GW, IceCube and KM3NeT for neutrino observations, and CTA for very high energy observations. These science themes encompass pressing issues in astrophysics, cosmology and fundamental physics such as: the central engine and jet physics in compact binary mergers, accretion processes and jet physics in Super-Massive Binary Black Holes (SMBBHs) and in compact stellar binaries, the equation of state of neutron stars, cosmic accelerators and the origin of Cosmic Rays (CRs), the origin of intermediate and high-Z elements in the Universe, the Cosmic distance scale and tests of General Relativity and the Standard Model. Observational strategies for implementing the identified science topics are also discussed. A significant part of the sources targeted by multi-messenger facilities is of transient nature. We have thus also discussed the synergy of Athena with wide-field high-energy facilities, taking THESEUS as a case study for transient discovery. This discussion covers all the Athena science goals that rely on follow-up observations of high-energy transients identified by external observatories, and includes also topics that are not based on multi-messenger observations, such as the search for missing baryons or the observation of early star populations and metal enrichment at the cosmic dawn with Gamma-Ray Bursts (GRBs).

Naxi Cosmology of Mt Yulong Sacred Sites with Caveats for Conservation

Mt Yulong is central to Naxi people of Southwest China. Through participatory mapping, free listing, and extended semi-structured interviews, we explored relations of Naxi cosmologies of sacred space with “biodiversity conservation”. For this commonly espoused partnership, we found encouragement, skepticism and challenges. Naxi perspectives on sacred space and conservation ranged in scale from hyper-local, through regional, to historical and cosmological. Some participants worried about conjoining religion with government conservation initiatives. Others argued conceptually that “conservation” prioritizes people while traditional Naxi cosmology stresses equality and brotherhood between people and nature. Challenges for conservation would be to integrate this cosmological view as well as origin myths, Naxi traditions of suicide, and Sanduo, the god of Mt Yulong, who “shines like lightning [and his] mouth spits fire” – not a deity to be engaged without care. Naxi stressed primacy of culture and cosmology. These cosmological issues raised in a local context are of far greater magnitude than one culture and one mountain and may suggest paths to effective conservation of sacred natural spaces around the world.

The Structure of Space and its Impact on Interplanetary Travel and Answers to Fundamental Cosmological Questions

The article presents the far-reaching implications of the theory entitled "Theory of Space" (Sobolewski D. S., Theory of Space, 2016) (Sobolewski D. S., Theory of Space, 2017) (Sobolewski D. S., Theory of Space, 2022 - new unpublished edition) and of the publication "New Generations of Rocket Engines" (Sobolewska, Sobolewska, Sobolewski, Sobolewski, & Sobolewski, 2021). Among others, it presents the shape of curved space in E4 for selected planets of the solar system and the Sun, taking into account boundary hypersurfaces and gravitational interactions. The existence of space tunnels was analysed and the perspective of new technologies enabling interplanetary travel was outlined. Furthermore, due to the revealed structure of space, cosmological issues including the existence of other Universes and possible effects of their interactions are addressed. The constant Gdańsk was also introduced GGdańsk which, together with the introduced equation, makes it possible to determine the maximum immersion depth of an astronomical object of mass M.

Mehmed Emin Üsküdârî’nin Sonsuzluğa Dair Şerhu’l-Berâhîni’l-hamse Adlı Risalesinin Tahlil ve Tahkiki

This article examines the form and content of Sharh al-Barāhīn al-khamsa, written by Mehmed Emīn Üsküdārī (d. 1149/1736-37), an important figure of eighteenth-century Ottoman Turkish philosophical thought, on the problems of the finitude of extensions and the invalidity of the idea of infinite regress. The subject of infinity appeals to a broad range of disciplines, being the mainstay of many theological questions such as the demonstrations for the existence of a necessary existent as well as many other epistemological, ontological, and cosmological issues. This question has historically concerned Peripatetic falāsifa and mutakallimūn from different intellectual traditions and has become part of a cosmopolitan theological and philosophical tradition in which distinct treatises were compiled by scholars of the post-Rāzīan period (mutaʾakhkhirūn). One of the last representatives of the late Ottoman period, Mehmed Emīn Üsküdārī, authored such a treatise on this question. This treatise is important as a window on the infinity question in Ottoman intellectual thought. In addition to the ladder (al-burhān al-sullamī) and collimation (burhān al-musāmata) demonstrations for the discussions on the infinity of extensions, this treatise also uses the mapping (burhān al-tatbīq), correlation (burhān al-tadāyuf), and throne (al-burhān al-ʿarshī) demonstrations as well as two other demonstrations mentioned by the Persian Mīrzā Jān Shīrāzī (d. 995/1587) for the discussions of infinite regress. In this context, Üsküdārī made a short and concise presentation of the aforementioned demonstrations, supporting some of them with geometric diagrams. This article consists of i) an analysis and ii) critical edition as its two main features and examines Üsküdārī’s evaluations of each of the demonstrations, their historical background, and their differences and similarities in terms of novelty and continuity.

Topics in Cosmology—Clearly Explained by Means of Simple Examples

This is a very comprehensible review of some key issues in modern cosmology. Simple mathematical examples and analogies are used, whenever available. The starting point is the well-known Big Bang cosmology (BBC). We deal with the mathematical singularities appearing in this theory and discuss some ways to remove them. Next, and before introducing the inflationary paradigm by means of clear examples, we review the horizon and flatness problems of the old BBC model. We then consider the current cosmic acceleration and, as a procedure to deal with both periods of cosmic acceleration in a unified way, we study quintessential inflation. Finally, the reheating stage of the universe via gravitational particle production, which took place after inflation ended, is discussed in clear mathematical terms, by involving the so-called α-attractors in the context of quintessential inflation.