Big Bang Research Articles

Predicting spatial curvature ΩK in globally CPT -symmetric universes

Boyle and Turok’s CPT-symmetric universe model posits that the Universe was symmetric at the big bang, addressing numerous problems in both cosmology and the Standard Model of particle physics. We extend this model by incorporating the symmetric conditions at the end of the Universe, which impose constraints on the allowed perturbation modes. These constrained modes conflict with the integer wave vectors required by the global spatial geometry in a closed universe. To resolve this conflict, only specific values of curvature are permissible, and in particular the curvature density is constrained to be ΩK∈{−0.016,−0.011,−0.004,…}, consistent with observations. Published by the American Physical Society 2024

Dark sector tunneling field potentials for a dark big bang

All of the significant evidence for dark matter observed thus far has been through its gravitational interactions. After 40 years of direct detection experiments, the parameter space for weakly interacting massive particles (WIMPs) as dark matter candidates is rapidly approaching the neutrino floor. Moreover, there have been no signs of WIMPs in any particle production experiments so far. In this light, we consider a dark sector that is strongly decoupled from the visible sector, interacting exclusively through gravity. In this model, proposed by Freese and Winkler [Dark matter and gravitational waves from a dark big bang, ], dark matter can be produced through a first-order phase transition in the dark sector dubbed “the dark big bang.” We fully determine the allowed region of parameter space for the tunneling potential that leads to the realization of a dark big bang and is consistent with all experimental bounds available. Published by the American Physical Society 2024

Early dark energy during big bang nucleosynthesis

We study the impact of an early dark energy component (EDE) present during big bang nucleosynthesis (BBN) on the elemental abundances of deuterium D/H, and helium Yp, as well as the effective relativistic degrees of freedom Neff. We consider a simple model of EDE that is constant up to a critical time. After this critical time, the EDE transitions into either a radiation component that interacts with the electromagnetic plasma, a dark radiation component that is uncoupled from the plasma, or kination that is also uncoupled. We use measured values of the abundances and Neff as determined by cosmic microwave background observations to establish limits on the input parameters of this EDE model. In addition, we explore how those parameters are correlated with BBN inputs; the baryon to photon ratio ηb, neutron lifetime τn, and number of neutrinos Nν. Finally, we study whether this setup can alleviate the tension introduced by recent measurements of the primordial helium abundance. Published by the American Physical Society 2024

Hybrid α -Ta/ β -Ta lumped element kinetic inductance detectors with photon noise limited sensitivity and stability

The terahertz (THz) band is of immense interest in astronomy as it encompasses significant energy generated following the Big Bang, offering critical insight into processes invisible in other bands, such as the earliest stages of planet, star, and galaxy formation. Kinetic inductance detectors (KIDs) have emerged as a formidable contender in the field of THz astronomy, attributed to their exceptional sensitivity and scalability. In this study, we introduce a kind of KIDs incorporating a lumped element (LE) resonator design, with inductors fabricated on β-Ta film and capacitors on α-Ta film. We characterize the noise of the hybrid α-Ta/β-Ta LEKIDs, achieving an optical noise equivalent power of 8.3 ± 5.7 × 10−19 W/Hz1/2, demonstrating high sensitivity. Additionally, the LEKIDs exhibited stability across multiple thermal cycles. The combination of high sensitivity and stability makes the hybrid LEKIDs promising for the stringent demands of THz astronomy.

Wind Turbine Operation Status Monitoring and Fault Prediction Methods Based on Sensing Data and Big Bang–Big Crunch Algorithm

As wind power generation technology rapidly advances, the threat of wind turbine failures to the secure and stable operation of the power grid is gaining increasing attention. Real-time monitoring of operation status and predicting potential failures in wind turbines are indispensable requirements for the safe integration of wind power. In this paper, a model based on the least squares support vector machine (LSSVM), whose parameters are optimized by the Big Bang–Big Crunch algorithm, is constructed to improve the monitoring of wind turbine operation status and fault prediction accuracy. The research methodology consists of several key stages. Firstly, the initial wind turbine sensing data are preprocessed, utilizing factor analysis to reduce dimensionality and obtain the main influencing factors of wind turbine operation. Then, an improved failure prediction model for wind turbines, based on the least squares support vector machine, is developed using the preprocessed data. The model parameters are optimized by utilizing the Big Bang–Big Crunch optimization algorithm to enhance the prediction accuracy of wind turbine failures. Finally, the feasibility and accuracy of the proposed method are validated through a case study conducted on a regional power grid with wind farm integration.

Characterizing gravitational wave detector networks: from A♯ to cosmic explorer

Abstract Gravitational-wave observations by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo have provided us a new tool to explore the Universe on all scales from nuclear physics to the cosmos and have the massive potential to further impact fundamental physics, astrophysics, and cosmology for decades to come. In this paper we have studied the science capabilities of a network of LIGO detectors when they reach their best possible sensitivity, called A#, given the infrastructure in which they exist and a new generation of observatories that are factor of 10 to 100 times more sensitive (depending on the frequency), in particular a pair of L-shaped Cosmic Explorer observatories (one 40 km and one 20 km arm length) in the US and the triangular Einstein Telescope with 10 km arms in Europe. We use science metrics derived from the top priorities of several funding agencies to characterize the science capabilities of different networks. The presence of one or two A# observatories in a network containing two or one next generation observatories, respectively, will provide good localization capabilities for facilitating multimessenger astronomy and precision measurement of the Hubble parameter. Two Cosmic Explorer observatories are indispensable for achieving precise localization of binary neutron stars, facilitating detection of electromagnetic counterparts and transforming multimessenger astronomy. Their combined operation is even more important in the detection and localization of high-redshift sources, such as binary neutron stars, beyond the star-formation peak, and primordial black hole mergers, which may occur roughly 100 million years after the Big Bang. The addition of the Einstein Telescope to a network of two Cosmic Explorer observatories is critical for accomplishing all the identified science metrics. For most metrics the triple network of next generation terrestrial observatories are a factor 100 better than what can be accomplished by a network of three A# observatories.

REPRESENTATION AND DEMOCRATIC PROCESS IN THE PRODUCTION OF ACCOUNTING STANDARDS BY THE IASB: A DISCURSIVE ANALYSIS

In a globalized world where representation and democratic values ​​are extolled, especially in the West, institutions that do not profess and practice them are criticized for lacking legitimacy. The International Accounting Standards Board (IASB), as a social institution, influences and is influenced by the social environment. However, criticism has been leveled at the institution regarding its legitimacy, especially because it is a private regulatory entity. Such criticism calls into question values ​​such as independence, public interest, due process, accountability, diversity, and representativeness. The objective of this paper is to analyze, based on some documents published by the IASB, the values ​​that this institution professes, seeking to confer the perception of legitimacy before the public. The theoretical premise adopted is that of social constructivism and institutional accounting theory, which advocate that meanings and symbols are social constructions and that, therefore, institutions play an important role in the creation, maintenance, or modification of symbolic universes, as well as in their legitimacy. Discourse Analysis (DA) will be used as an instrument capable of revealing the values ​​advocated by the IASB. In the end, it is found that the IASB has professed values ​​such as representativeness, diversity, transparency, due process, public interest, independence, and accountability, seeking to legitimize itself before the public. In this sense, this article contributes to highlighting that the IASB's discourse is in tune with social values ​​dear to the Western world.

The ‘Universe in a Box’: a hands-on activity to introduce primary school students to cosmology

Abstract Physics Education Research shows that active learning and interdisciplinary strategies can enhance students’ engagement in physics. In primary school, the implementation of active learning pedagogies such as Inquiry-Based Science Education aims to encourage students’ autonomy and participation in their learning process. Indeed, active learning promotes pupils’ creativity, helping them develop the skills that increasingly determine their future employability and personal development, introducing them to STEM. In this regard, stories and storytelling can help improve teaching and students’ physics learning. Telling the Universe and its history can afford this job. The Big Bang, the Cosmic Microwave Background, and the formation of stars and planets are valuable tools for introducing primary school students to physics and the scientific method while fostering their curiosity about science. Moreover, it helps the instructors monitor the development of peculiar misconceptions on these topics, preventing them from fully understanding physics phenomena. In this paper, we present an innovative short-term program (one session of three hours) called ‘The Universe in a Box’ to introduce primary school students (grades 4–5, ages 9–10) to cosmology. We illustrate our design and the educational purposes of the program and present the outcomes from its implementation in five different laboratories in Sardinia, Italy, from 2022 to 2024 (60 students involved). This work can furnish a theoretical and methodological guide for primary school teachers and instructors on integrating formal curricula with contemporary physics topics using interdisciplinary approaches, engaging their students in STEAM (STEM plus Arts).

A super-Eddington-accreting black hole ~1.5 Gyr after the Big Bang observed with JWST

A super-Eddington-accreting black hole ~1.5 Gyr after the Big Bang observed with JWST

Data Analysis of LHC Heavy Ion Collision for QGP Study

Abstract. By recreating the first kind of matter in the history of the universe, the quark-gluon plasma (QGP), through PbPb collisions, scientists can study the state of the early universe after the big bang. In this paper, the data from PbPb collisions collected by the Alice experiment at Large Hardron Collider is analyzed to investigate the properties of the QGP. The team focused on Fourier decomposition of azimuthal and angular correlation analysis, using data at a center-of-mass energy of 5.02 TeV per nucleon pair. The distributions of the transverse momentum p_T, the pseudo-rapidity and the azimuth angle were plotted and analyzed. The shapes of plots didnt perfectly match the predictions because of data fluctuations and the limitations of detectors. However, the trend of positive correlation between the coefficients and the transverse momentum p_T was found. The results confirm previous research findings on the collective motion and anisotropic flow of QGP. The study provides insights into the QGP's behavior and supports the theoretical predictions about its properties.

Indirect Measurement of the 3He(n,p)3H Reaction Cross Section at Big Bang Energies

Neutron-induced nuclear reactions play an important role in the Big Bang Nucleosynthesis. Their excitation functions are, from an experimental point of view, usually difficult to measure. Nevertheless, in the last decades, big efforts have led to a better understanding of their role in the primordial nucleosynthesis network. In this work, we apply the Trojan Horse Method to extract the cross section at astrophysical energies for the 3He(n,p)3H reaction after a detailed study of the 2H(3He,pt)H three-body process. Data extracted from the present measurement are compared with other published sets. The reaction rate is also calculated, and the impact on the Big Bang nucleosynthesis is examined in detail.

Low [O/Fe] Ratio in a Luminous Galaxy at the Early Cosmic Epoch (z > 10): Signature of Short Delay Time or Bright Hypernovae/Pair-instability Supernovae?

Abstract We present an [O/Fe] ratio of a luminous galaxy GN-z11 at z = 10.60 derived with the deep public JWST/NIRSpec data. We fit the medium-resolution grating (G140M, G235M, and G395M) data with the model spectra consisting of BPASS-stellar and Cloudy-nebular spectra in the rest-frame UV wavelength ranges with Fe absorption lines, carefully masking the other emission and absorption lines in the same manner as previous studies conducted for lower-redshift (z ∼ 2–6) galaxies with oxygen abundance measurements. We obtain an Fe-rich abundance ratio [ O / Fe ] = − 0.37 − 0.22 + 0.43 , which is confirmed with the independent deep prism data as well as by the classic 1978 index method. This [O/Fe] measurement is lower than that measured for star-forming galaxies at z ∼ 2–3. Because z = 10.60 is an early epoch after the Big Bang (∼430 Myr) and the first star formation (likely ∼200 Myr), it is difficult to produce Fe by Type Ia supernovae (SNe Ia), which requires sufficient delay time for white-dwarf formation and gas accretion. The Fe-rich abundance ratio in GN-z11 suggests that the delay time is short or that the major Fe enrichment is not accomplished by SNe Ia but by bright hypernovae (BrHNe) and/or pair-instability supernovae (PISNe), where the yield models of BrHNe and PISNe explain Fe, Ne, and O abundance ratios of GN-z11. The [O/Fe] measurement is not too low to rule out the connection between GN-z11 and globular clusters (GCs) previously suggested by the nitrogen abundance but rather supports the connection with a GC population at high [N/O] if a metal dilution process exists.

Professor Namburi Hanumanta Rao: A master innovator who shaped Ayurveda Pharmaceutics

Abstract Many legendary Ayurvedic physicians in Andhra Pradesh have dedicated their lives to patronizing Ayurveda on par with the Allopathic system, and some contributed to Ayurveda through their research, practice, orientation, teaching, manufacturing of medicines, and publication. Namburi Hanumanta Rao (NHR) is a man with all the above skills. Prof. Rao is considered a great Ayurvedic scholar and pioneer in Rasashastra. Prof. Rao did his research in many branches of Ayurveda and had good practice, orientation, teaching ability, skills in manufacturing medicines, and publications. Prof. Rao contributed a lot to propagating Ayurveda on scientific lines. Prof. Rao established Dr. Rao’s Herbal Pharma Pvt. Ltd. in 1987. Diabetes, arthritis, and hair care are three significant components of his pharmacy. He published works like the Manual of Numburi Phased Spot Test (Qualitative standardization of Bhasmas and Sindhuras), Panchabhuta theory (A study of Panchabhuta at the molecular level), and the Nyaya Vaiseshika theory of the Evolution of the Universe closely correlates with the Big Bang theory of modern scientists. He established The Academy of Ayurveda, Sevaniketan, and Yoga Samaj organizations. He innovated many new techniques in Rsasasastra. NHR was a member of many governments and voluntary organizations, received many awards, presented scientific papers in many national and international seminars, visited foreign countries, and served to enrich the Ayurvedic system of medicine in the country and abroad. He was a highly respected personality whose life can be summarized with the quote, “Be Ayurvedist; be Proud of it.”

Experimental demonstration of two types of galaxies: matter galaxies and antimatter galaxies

This paper presents a novel analysis of galaxy formation through the lens of the Small Bang Model, which posits the existence of two distinct types of galaxies generated by micro black holes: matter galaxies generated by antimatter supermassive black holes (SMBHs) and antimatter galaxies generated by matter SMBHs. The relationship between the mass of galaxies and their respective SMBHs is explored, leading to the derivation of two specific mass ratios: 918 for matter galaxies and 324 for antimatter galaxies. By using a dataset of 100 galaxies from a reliable source, the research identifies two separate subsets of galaxies with low measurement error, totaling 41 galaxies. Among these, 31 galaxies (77%) are identified as matter galaxies with a mass ratio of 918, while 10 galaxies (23%) are classified as antimatter galaxies with a mass ratio of 324. The analysis reveals that, despite measurement noise, the data aligns closely with the theoretical predictions for these two distinct types of galaxies. The research provides a strong indication that galaxies and their SMBHs are governed by fixed mass relationships, challenging the idea that these relationships are random or nonlinear. This supports the Small Bang Model, which offers a compelling alternative to the Big Bang Model, with no initial singularity and a universe emerging from a low-energy state. The findings suggest that this model not only explains the formation of spiral galaxies but also accounts for the origin of supermassive black holes at the center of each galaxy. Further study is encouraged, as this discovery opens new avenues for understanding the role of antimatter in the universe and the formation of galaxies.

Absolute Reference for Microwave Polarization Experiments. The COSMOCal Project and its Proof of Concept

Context. The cosmic microwave background (CMB), a remnant of the Big Bang, provides unparalleled insights into the primordial universe, its energy content, and the origin of cosmic structures. The success of forthcoming terrestrial and space experiments hinges on meticulously calibrated data. Specifically, the ability to achieve an absolute calibration of the polarization angles with a precision of <0.°1 is crucial to identify the signatures of primordial gravitational waves and cosmic birefringence within the CMB polarization. Aims. We introduce the COSmological Microwave Observations Calibrator project, designed to deploy a polarized source in space for calibrating microwave frequency observations. The project aims to integrate microwave polarization observations from small and large telescopes, ground-based and in space, into a unified scale, enhancing the effectiveness of each observatory and allowing robust combination of data. Methods. To demonstrate the feasibility and confirm the observational approach of our project, we developed a prototype instrument that operates in the atmospheric window centered at 260 GHz, specifically tailored for use with the NIKA2 camera at the IRAM 30 m telescope. Results. We present the instrument components and their laboratory characterization. The results of tests performed with the fully assembled prototype using a Kinetic Inductance Detectors-based instrument, similar concept of NIKA2, are also reported. Conclusions. This study paves the way for an observing campaign using the IRAM 30 m telescope and contributes to the development of a space-based instrument.

Parametrically amplified super-radiance towards hot big bang universe

Parametrically amplified super-radiance towards hot big bang universe

Self-consistent Strong Screening Applied to Thermonuclear Reactions

Self-consistent strong plasma screening around light nuclei is implemented in the Big Bang nucleosynthesis (BBN) epoch to determine the short-range screening potential, e ϕ(r)/T ≥ 1, relevant for thermonuclear reactions. We numerically solve the nonlinear Poisson–Boltzmann equation incorporating Fermi–Dirac statistics, adopting a generalized screening mass to find the electric potential in the cosmic BBN electron–positron plasma for finite-sized α particles (4He++) as an example. Although the plasma follows Boltzmann statistics at large distances, Fermi–Dirac statistics is necessary when work performed by ions on electrons is comparable to their rest-mass energy. While self-consistent strong screening effects are generally minor owing to the high BBN temperatures, they can enhance the fusion rates of high-Z (Z > 2) elements while leaving fusion rates of lower-Z (Z ≤ 2) elements relatively unaffected. Our results also reveal a pronounced spatial dependence of the self-consistent strong screening potential near the nuclear surface. These findings about the electron–positron plasma’s role refine BBN theory predictions and offer broader applications for studying weakly coupled plasmas in diverse cosmic and laboratory settings.

Einstein, tea leaves, meandering rivers, and the origin of supermassive black holes in ekpyrotic universe

Central supermassive black holes are found in most massive galaxies. However, their origin is still poorly understood. Observations of quasars show that many supermassive black holes existed less than 700 million years after the Big Bang. To explain the existence of such black holes with masses comparable to the stellar mass of the host galaxy, just 500 million years after the Big Bang, it is probably necessary to assume that they originated from heavy seeds. In an ekpyrotic universe, a hot Big Bang occurs as a result of the collision of two branes. Quantum fluctuations create ripples on the brane surfaces, leading to spatial variations in the timing of collisions, thereby creating density perturbations that can facilitate the formation of massive black hole seeds. I hypothesize that perhaps Rayleigh–Bénard–Marangoni-type convection in the extra dimension is a more efficient source of macroscopic density perturbations than quantum fluctuations.

Entanglement production through a cosmological bounce

In quantum cosmology, it is expected that the Big Bang singularity is resolved and the universe undergoes a bounce. We find that for Gaussian initial states, matter-gravity entanglement entropy rises rapidly during the bounce, declines, and then approaches a steady-state value following the bounce. These observations suggest that matter-gravity entanglement is a feature of the macroscopic universe and that there is no Second Law of entanglement entropy.

Revisiting dark photon constraints from CMB spectral distortions

Abstract Spectral distortions of the cosmic microwave background (CMB) provide stringent constraints on energy and entropy production in the post-BBN (Big Bang Nucleosynthesis) era. This has been used to constrain dark photon models with COBE/FIRAS and forecast the potential gains with future CMB spectrometers. Here, we revisit these constraints by carefully considering the photon to dark photon conversion process and evolution of the distortion signal. Previous works only included the effect of CMB energy density changes but neglected the change to the photon number density. We clearly define the dark photon distortion signal and show that in contrast to previous analytic estimates the distortion has an opposite sign and a ≃ 1.5 times larger amplitude. We furthermore extend the treatment into the large distortion regime to also cover the redshift range ≃ 2 × 106 − 4 × 107 between the μ-era and the end of BBN using CosmoTherm. This shows that the CMB distortion constraints for dark photon masses in the range 10−4 eV ≲ md ≲ 10−3 eV were significantly underestimated. We demonstrate that in the small distortion regime the distortion caused by photon to dark photon conversion is extremely close to a μ-type distortion independent of the conversion redshift. This opens the possibility to study dark photon models using CMB distortion anisotropies and the correlations with CMB temperature anisotropies as we highlight here.