Cadernos de Astronomia
type: channel
description: A revista Cadernos de Astronomia é uma publicação semestral do Núcleo Cosmo-Ufes da Universidade Federal do Espírito Santo e que conta também com recursos humanos do Centro Brasileiro de Pesquisas Físicas e da Universidade Federal de Ouro Preto (vide o Corpo Editorial). Propõe-se a publicar artigos destinados à divulgação científica, história da ciência, ensino e pesquisa em astronomia e áreas correlatas. O objetivo é tornar acessível a um amplo público, que inclui estudantes secundários, graduandos e simpatizantes da área, o conhecimento científico relacionado à astronomia, cosmologia e gravitação. Possuindo acesso totalmente gratuito, cada número dedica uma seção inteira a um tema específico, onde especialistas nacionais e internacionais discutem em detalhes aspectos qualitativos e quantitativos do tópico em questão. A partir de 2023 os números semestrais dos CdA serão publicados nos meses de Março e Setembro. Cada um desses números possuem datas limite para receber submissões: Números publicados em Março - Submissões feitas até 10 de Janeiro; Números publicados em Setembro - Submissões feitas até 1º de Julho. Submissões recebidas após as datas limite acima não terão garantias de que, uma vez aceitas para publicação, façam parte do próximo número. Não sendo publicadas no próximo número, elas são automaticamente programadas para publicação no número subsequente a ser lançado.
publisher: UFES
language: en
publication name: Cadernos de Astronomia
issn: 2675-4754
items: Front matters
items: Dark energy and the challenges to the standard cosmological model
items: Cosmological considerations on the general theory of relativity.
items: Challenges in astroparticles
items: Massive neutrinos in cosmology: geometry and growth of structures
items: Many worlds interpretation of quantum mechanics? - It is simple!
items: Kepler's laws: inferring the mass of Sagittarius A*
items: Challenges in the search for gravitational wave signals
items: Photometry and calibration of Type Ia supernovae
items: Cosmological tensions in H0 and S8: current overview
items: Earth's and Mars' atmospheres: an astrobiological approach
items: Front Matter
items: Niède Guidon, Serra da Capivara and celestial records in rock art: science, culture and archaeoastronomy in the Piauí caatinga
items: The 2025 Nobel Prize in Physics
items: Little red dots
items: Commented translation of Heisenberg's paper, “On the reinterpretation of kinematic and mechanical relations in quantum theory”
items: The mathematical symphony of the quantum world
items: Formation and evolution of large-scale structures from the perspective of halo models
items: The quantum mechanics in construction
items: Telescopes: history and applications in astronomy
items: Quantum degeneracy and white dwarfs
items: Density functional theory: foundations, challenges, and new horizons in the quantum mechanics of atoms, molecules, and solids
items: Revisiting Duhem: quasars, cosmology, and the tripartite relationship between theories and experiments.
items: Quantum effects in curved spaces: from the particle concept to field theory
items: The problem of time in gravitation and cosmology
items: Tests of quantum gravity in the laboratory
items: The black hole information paradox
items: Quantum effects in gravitation and gravitational analogues
items: A forgotten Pioneer: Guido Beck and the prediction of gravitational waves
items: The rebirth of general relativity: theses and historiographical perspectives

Front matters
type: item
description: It includes the editorial information for this edition, the Letter to the Reader, and the Table of Contents.
subject: Editorial
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Os Editores
rights: Copyright (c) 2026 Os Editores https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 1
ending page: 5
doi: 10.47456/Cad.Astro.v7n1.52275

Dark energy and the challenges to the standard cosmological model
type: item
description: Observational evidence that the Universe is undergoing accelerated expansion represents one of the main challenges of modern cosmology, usually attributed to the presence of a dominant component known as dark energy. The standard cosmological model, ΛCDM, provides a consistent description of a wide range of observations, but faces significant difficulties from both a theoretical and observational standpoint. In this article, we present a review of the ΛCDM model, discussing its theoretical foundation and the main observational tests that support its validity. We emphasize recent observational strains, such as those associated with the Hubble constant (H0) and the amplitude of matter fluctuations (S8), as well as recent results from the DESI survey that suggest possible deviations from the standard model. We also discuss the implications of these strains and possible extensions of the model, highlighting the role of scenarios with dynamic dark energy. This overview seeks to provide an updated view of the challenges faced by contemporary cosmology and the prospects for understanding cosmic acceleration.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Jailson Alcaniz
creator: Rodrigo Von Marttens
creator: Saulo Carneiro
rights: Copyright (c) 2026 Rodrigo Von Marttens, Jailson Alcaniz, Saulo Carneiro https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 62
ending page: 76
doi: 10.47456/Cad.Astro.v7n1.52249

Cosmological considerations on the general theory of relativity.
type: item
description: We present the translation of the article published by Albert Einstein in 1917. In it, he introduces, for the first time, a cosmological constant, a term that today plays a very important role in the standard model of cosmology. Some introductory comments are presented, followed by the Portuguese version of the text originally written in German.
subject: Textos Clássicos
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Albert Einstein
creator: Júlio César Fabris
creator: Oliver Fabio Piattella
rights: Copyright (c) 2026 Albert Einstein; Júlio C. Fabris (trad.), Oliver F. Piattella (trad.) https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 145
ending page: 155
doi: 10.47456/Cad.Astro.v7n1.52177

Challenges in astroparticles
type: item
description: Astroparticle physics plays a central role in addressing fundamental questions in modern physics by connecting particle physics, cosmology, and astrophysics. Among the main problems, we highlight the nature of dark matter and dark energy, primordial inflation, the matter-antimatter asymmetry of the universe, and the origin of ultra-high-energy cosmic messengers. In this article, we review the main observational evidence for dark matter, which spans scales from galactic to cosmological, and discuss the two most explored scenarios for its nature: primordial black holes and new fundamental particles beyond the Standard Model. We explore the main theoretical and experimental bottlenecks that challenge the search for the nature of dark matter, highlighting those associated with extended mass distributions of primordial black holes and the absence of weakly interacting massive particle signals in direct, indirect, and accelerator detection experiments. We also discuss the role of next-generation experiments, including very high-energy gamma-ray telescopes and multi-messenger detectors. Finally, we conclude that the combination of high-precision observations and theoretical advances will be crucial to elucidating the microphysics of dark matter and deepening our understanding of the extreme universe.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Clarissa Siqueira
rights: Copyright (c) 2026 Clarissa Siqueira https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 52
ending page: 61
doi: 10.47456/Cad.Astro.v7n1.52150

Massive neutrinos in cosmology: geometry and growth of structures
type: item
description: Neutrinos are the most abundant particles in the Universe after photons, yet their masses remain unknown. In this article we show how modern cosmology provides a powerful way to investigate this fundamental property through the Cosmic Microwave Background, baryon acoustic oscillations, and the growth of large-scale structure. We discuss how neutrinos, relativistic in the early Universe and non-relativistic at late times, leave imprints both on the expansion history and on the formation of the cosmic web. We also show how recent galaxy survey data, such as DESI, combined with cosmological simulations, allow increasingly precise constraints on the sum of neutrino masses, turning the Universe into a powerful detector of these particles.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Guilherme Brando
rights: Copyright (c) 2026 Guilherme Brando https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 25
ending page: 39
doi: 10.47456/Cad.Astro.v7n1.51840

Many worlds interpretation of quantum mechanics? - It is simple!
type: item
description: We describe in a relatively popular way the main ideas of the many-worlds interpretation of quantum mechanics. We discuss the question about its “counter-intuitiveness” citing some literature works written before and after its invention.
subject: Divulgação Científica, Ciência e Sociedade
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Alexander Kamenshchik
rights: Copyright (c) 2026 Alexander Yu. Kamenshchik https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 84
ending page: 96
doi: 10.47456/Cad.Astro.v7n1.51564

Kepler's laws: inferring the mass of Sagittarius A*
type: item
description: This article aims to present an investigative approach to the study of black holes in light of Newtonian Mechanics, with a mathematical formulation developed by a high school student. The proposal involves the use of fundamental concepts such as Newton's Laws, Kepler's Laws, and the Law of Universal Gravitation. The study begins with a historical and theoretical contextualization, followed by a brief discussion of the scientific confirmation of the existence of black holes, highlighting the case of Sagittarius A*, a supermassive object located at the center of the Milky Way. Through orbital analysis of stars near this object, based on literature data, and using Kepler's Third Law, its mass was estimated. The data were processed using a spreadsheet, allowing for statistical analysis. The comparison between the obtained results, namely (4.46 ± 0.01) × 10⁶ M⊙, and those found in the literature showed an uncertainty of ≈ 4%. Thus, the potential of classical mechanics as an introductory tool in teaching advanced concepts in astronomy becomes evident.
subject: Artigos
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Mateus Barbosa Ferreira
creator: Adriano Mesquita Oliveira
rights: Copyright (c) 2026 Mateus Barbosa Ferreira, Adriano Mesquita Oliveira https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 112
ending page: 118
doi: 10.47456/Cad.Astro.v7n1.51335

Challenges in the search for gravitational wave signals
type: item
description: This paper presents the challenges faced in the search for gravitational-wave signals by the LIGO detectors, arising from the presence of noise in the data. Such noise can couple to the interferometers through different physical mechanisms associated with the environment or the instrumentation. As a consequence, it can affect the parameter estimation of real detections, reduce the statistical significance of observed events, or, in some cases, mimic astrophysical signals.
subject: Divulgação Científica, Ciência e Sociedade
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Tábata Aira Ferreira
rights: Copyright (c) 2026 Tábata Aira Ferreira https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 77
ending page: 83
doi: 10.47456/Cad.Astro.v7n1.51540

Photometry and calibration of Type Ia supernovae
type: item
description: Type Ia supernovae provided the first evidence, by the end of the 1990's, that the expansion of the Universe is accelerated. Since then, various groups, using different observations have been confirmed this pioneer result, indicating that the Universe is in phase dominated by a cosmological constant, which is the simplest mechanism to explain the cosmic acceleration, in the context of general relativity. However, as the observation techniques were improving, the number of observed events increased to a point at the statistical uncertainties are not the biggest problem. The main focus of new projects shifted to controlling systematic errors due to modeling of the phenomenon, observation conditions e equipment limitations. In this work, we present a small glimpse of the photometry challenge, regarding the observation of astronomical events em large wavelenght bands and, from this information, infer intrinsic properties of such events. In addition, in briefly consider the challenge of controlling the propagation of uncertainties to the estimated distances e, consequently, to the cosmological parameters obtained from them.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Ribamar Reis
creator: Beatriz Siffert
rights: Copyright (c) 2026 Ribamar R. R. Reis, Beatriz B. Siffert https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 40
ending page: 51
doi: 10.47456/Cad.Astro.v7n1.51476

Cosmological tensions in H0 and S8: current overview
type: item
description: The standard cosmological model has provided, for several decades, a consistent description of a wide range of cosmological and astrophysical observations. Despite this success, persistent discrepancies in the determination of fundamental parameters, in particular the Hubble constant (H0) and the amplitude of structure growth, commonly parametrized by S8, reveal significant tensions between probes of the early and late universe, with varying levels of statistical significance. These tensions may be partially associated with systematic uncertainties that are not yet fully understood, but they also motivate the investigation of extensions of ΛCDM, including modifications to dark energy, the dark sector, and gravity on large scales. In this didactic review, we present an overview of the main observations currently involved in these discrepancies, discuss their potential observational biases, and synthesize the most relevant theoretical scenarios, highlighting the prospects offered by current-generation cosmological surveys.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Emanuelly Silva
creator: Miguel Sabogal
creator: Rafael Nunes
rights: Copyright (c) 2026 Emanuelly Silva, Miguel Sabogal, Rafael Nunes https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 6
ending page: 24
doi: 10.47456/Cad.Astro.v7n1.51444

Earth's and Mars' atmospheres: an astrobiological approach
type: item
description: This article compares the atmospheres of Earth and Mars from an astrobiological perspective, examining their evolution, composition, and the processes that determine habitability. For Earth, it discusses formation and climate regulation by the oceans and the sequestration of CO2 through sedimentation, the rise of an O2-rich atmosphere (the Great Oxidation Event, GOE), and the roles of N2, O2, and O3 in maintaining liquid water and supporting life. For Mars, it analyzes the current low-pressure, CO2-dominated atmosphere, atmospheric and water loss, the intensity of surface radiation, and the soil’s oxidizing chemistry that compromise the preservation of organic matter. The text emphasizes the complementarity between atmospheric studies and subsurface investigations, identifying subsurface refugia, with lower radiation doses and reduced chemical oxidation, as the most promising locations for biosignature preservation. The article adopts a didactic, integrative approach intended to help students and enthusiasts in astronomy and astrobiology understand the key processes that govern planetary habitability.
subject: Artigos
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Gustavo Rodrigues
creator: Anthony Henrique Perucci Mostaro
rights: Copyright (c) 2026 Gustavo Santos Rodrigues, Anthony Henrique Perucci Mostaro https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 119
ending page: 133
doi: 10.47456/Cad.Astro.v7n1.51028

Front Matter
type: item
description: Editorial information of the 6th volume, issue 2, from Cadernos de Astronomia (2025). Copyright page, Letter to Readers and Table of Contents.
subject: Editorial
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Os Editores
rights: Copyright (c) 2025 Os Editores https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 1
ending page: 5

Niède Guidon, Serra da Capivara and celestial records in rock art: science, culture and archaeoastronomy in the Piauí caatinga
type: item
description: This article explores the trajectory of archaeologist Niède Guidon and her scientific-cultural legacy based on her discoveries in Serra da Capivara, Piauí. Based on her contribution to Brazilian archaeology and the importance of Serra da Capivara National Park as a world heritage site, we discuss the role of science and education in preserving historical memory and valuing indigenous cultures. Finally, we analyze the archaeoastronomical potential of the region's rock paintings, exploring the possible relationship between prehistoric graphic records and celestial observations of its ancient inhabitants. The analysis adopts an interdisciplinary perspective, integrating archaeology, cultural astronomy and history of science.
subject: Divulgação Científica, Ciência e Sociedade
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Viviana Borges Corte
creator: Rizalva dos Santos Cardoso Rabelo
rights: Copyright (c) 2025 Viviana Borges Corte, Rizalva dos Santos Cardoso Rabelo https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 152
ending page: 160
doi: 10.47456/Cad.Astro.v6n2.50413

The 2025 Nobel Prize in Physics
type: item
description: <pre id="tw-target-text" class="tw-data-text tw-text-large tw-ta" dir="ltr" tabindex="-1" role="text" data-placeholder="Tradução" data-ved="2ahUKEwiM24zG16uQAxU6rJUCHVvwJVoQ3ewLegQIDBAV" aria-label="Texto traduzido: Brief comments by Brazilian physicists Ulysses Câmara da Silva (Federal University of Espírito Santo), Nelson Pinto Neto (Brazilian Center for Physics Research), and Olival Freire (Federal University of Bahia) on the 2025 Nobel Prize in Physics, which highlights work demonstrating quantum properties in non-microscopic systems.">Brief comments by Brazilian physicists Ulysses Câmara da Silva (Federal University of Espírito Santo), Nelson Pinto Neto (Brazilian Center for Physics Research), and Olival Freire (Federal University of Bahia) on the 2025 Nobel Prize in Physics, which highlights work demonstrating quantum properties in non-microscopic systems.
subject: Notas
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Júlio C. Fabris
rights: Copyright (c) 2025 Júlio C. Fabris https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 216
ending page: 218
doi: 10.47456/Cad.Astro.v6n2.50399

Little red dots
type: item
description: Explanatory note about the so-called little red dots (LRDs), observed by the James Webb Telescope. These compact, high-mass objects would have formed at a time when the universe was still quite young, which raises questions within the scientific community, since there wouldn't be enough time for objects with such pronounced reddish brightness, characteristic of old galaxies, to form.
subject: Notas
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Stéfani Faller
rights: Copyright (c) 2025 Stéfani Faller https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 219
ending page: 220
doi: 10.47456/Cad.Astro.v6n2.50388

Commented translation of Heisenberg's paper, “On the reinterpretation of kinematic and mechanical relations in quantum theory”
type: item
description: We present the translation of the article published by Werner Heisenberg in 1925, which constitutes a landmark in the development of quantum mechanics. Some introductory comments are presented, followed by the Portuguese version of the text originally written in German.
subject: Textos Clássicos
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Júlio César Fabris
creator: Oliver Fabio Piattella
rights: Copyright (c) 2025 Júlio C. Fabris, Oliver F. Piattella https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 184
ending page: 198
doi: 10.47456/Cad.Astro.v6n2.50081

The mathematical symphony of the quantum world
type: item
description: This text explores the profound and beautiful interplay between quantum physics and mathematics. We jour ney from the crisis of classical physics at the turn of the 20th century to the elegant, abstract mathematical frameworks that define modern quantum mechanics. We will see how physical problems forced the invention of new mathematics and how mathematical structures, in turn, provided the language to describe the quantum realm. Key figures like Planck, Einstein, Heisenberg, Born, von Neumann, Weyl, and Dirac will guide us,revealing a story where physical intuition and mathematical formalism are inextricably linked.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Giuseppe Dito
rights: Copyright (c) 2025 Giuseppe Dito https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 6
ending page: 15
doi: 10.47456/Cad.Astro.v6n2.50080

Formation and evolution of large-scale structures from the perspective of halo models
type: item
description: The current era of large-scale structure research, driven by projects such as DESI, Euclid, and LSST, demands efficient methods for modeling and interpreting vast datasets. The matter power spectrum, P(k, z), is a central statistical estimator in these efforts, but its modeling on nonlinear scales remains an ongoing challenge in the literature. In this context, halo models provide a powerful approach by associating the distribution of matter with halos of different masses. Widely used in tools such as HALOFIT and HM-CODE, these models play a fundamental role in data analysis and cosmological parameter inference. This article aims to provide an introductory and didactic resource that reviews the essential components of halo models, highlighting their advantages, such as flexibility beyond the standard ΛCDM model, and their impact on galaxy property predictions, observational studies, and theoretical modeling. The review is presented in a clear and accessible manner, aiming to introduce this approach, which will become increasingly indispensable in modern cosmology.
subject: Artigos
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Emanuelly Silva
creator: Rafael C. Nunes
rights: Copyright (c) 2025 Emanuelly Silva, Rafael C. Nunes https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 161
ending page: 170
doi: 10.47456/Cad.Astro.v6n2.48290

The quantum mechanics in construction
type: item
description: Quantum mechanics was developed in the early 20th century as a computational algorithm to organize and predict the strange results of a wide variety of experiments involving the microscopic world (molecules, atoms, elementary particles), which appeared random but had a predictable probabilistic distribution. Despite its overwhelming success, the conceptual foundations of this algorithm remain unclear and extremely controversial. How can we connect the microscopic world described by quantum mechanics with the macroscopic world of our daily experience? What is the role of observers in this connection? Why don't strange quantum phenomena occur on macroscopic scales? How can we explain the nonlocal nature of quantum phenomena? In this article I will present some attempts to answer these and other basic questions, which constitute different theories with completely different worldviews, commenting on their strengths and weaknesses. We will conclude that quantum theory is still under construction, as there is no consensual formulation. Its development is a fundamental problem in contemporary physics, and in thought in general.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Nelson Pinto Neto
rights: Copyright (c) 2025 Nelson Pinto Neto https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 16
ending page: 26
doi: 10.47456/Cad.Astro.v6n2.50044

Telescopes: history and applications in astronomy
type: item
description: <div id="tw-container" class="nev7se" data-cp="1" data-nnttsvi="1" data-sletp="false" data-sm="1" data-ssbp="false" data-sugg-time="500" data-sugg-url="https://clients1.google.com/complete/search" data-uilc="pt-BR" data-vil=",af,af-ZA,am,am-ET,ar-EG,ar-AE,ar-KW,ar-QA,ar,ar-IL,ar-JO,ar-LB,ar-PS,az,az-AZ,bg,bg-BG,bn,bn-BD,bn-IN,ca,ca-es,cs,cs-CZ,de,de-DE,de-CH,de-AT,de-LI,en,en-US,en-CA,en-AU,en-NZ,en-GB,en-IN,en-KE,en-TZ,en-NG,en-GH,en-PH,en-ZA,es,es-ES,es-AR,es-UY,es-419,es-BO,es-CL,es-CR,es-CO,es-DO,es-EC,es-GT,es-HN,es-NI,es-PA,es-PE,es-PR,es-PY,es-SV,es-VE,es-MX,es-US,eu,eu-ES,fi,fi-FI,fr,fr-FR,fr-CH,fr-BE,gl,gl-ES,gu,gu-IN,he,he-IL,iw,iw-IL,hu,hu-HU,hy,hy-AM,id,id-ID,is,is-IS,it,it-IT,it-CH,ja,ja-JP,jv,jv-ID,ka,ka-GE,km,km-KH,kn,kn-IN,ko,ko-KR,la,lo,lo-LA,lv,lv-LV,ml,ml-IN,mr,mr-IN,ms,ms-MY,nl,nl-NL,nb,nb-NO,ne,ne-NP,pl,pl-PL,pt,pt-BR,pt-PT,ro,ro-RO,ru,ru-RU,si-LK,sk,sk-SK,sr,sr-RS,su,su-ID,sv,sv-SE,sw,sw-TZ,sw-KE,ta,ta-IN,ta-SG,ta-LK,ta-MY,te,te-IN,tr,tr-TR,ur,ur-PK,ur-IN,yue,yue-HK,yue-Hant-HK,zh-HK,zh,zh-CN,zh-cmn,zh-cmn-CN,zh-Hans,zh-Hans-CN,zh-cmn-Hans,zh-cmn-Hans-CN,cmn-CN,cmn-Hans,cmn-Hans-CN,zh-TW,zh-Hant-TW,cmn-TW,cmn-Hant-TW,zh-cmn-TW,zh-cmn-Hant-TW,zu,zu-ZA,hi,hi-IN,tl,tl-PH,pa,pa-IN"> <pre id="tw-target-text" class="tw-data-text tw-text-large tw-ta" dir="ltr" tabindex="-1" role="text" data-placeholder="Tradução" data-ved="2ahUKEwj32f3Sw8CTAxVmg5UCHX0RE2cQ3ewLegQIDBAW" aria-label="Texto traduzido: This article presents an account of an experience carried out in a municipal elementary school in Linhares-ES, with some 9th-grade students. The reflection stems from the participation of the E.M.E.F. “Prefeito Roberto Calmon” school in the Espírito Santo Astronomy Exhibition. With the aim of advancing astronomy studies in the school context, we present a comprehensive research project on the topic: Telescopes, from their beginnings to the present day. Our research sought information about the equipment, personalities, and contributions to astronomy. The top…
subject: Ensino
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Alexsandra de Souza Batista
creator: Francisco Soares dos Anjos Neto
creator: Ray Rodrigues Oliveira Borges
creator: Ruan Silva De Sá
creator: Roger da Trindade Gomes
rights: Copyright (c) 2026 Alexsandra de Souza Batista , Francisco Soares dos Anjos Neto, Ray Rodrigues Oliveira Borges , Ruan Silva De Sá, Roger da Trindade Gomes https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 134
ending page: 144
doi: 10.47456/Cad.Astro.v7n1.49992

Quantum degeneracy and white dwarfs
type: item
description: White dwarfs are highly compact stellar remnants resulting from the evolutionary process of stars with masses up to ten times that of our Sun. Their core is composed predominantly of electronically degenerate matter. In an ordinary star, there is a balance between the intrinsic gravitational attraction and the internal pressure generated by the heat and nuclear radiation from its core. In a white dwarf, collapse is prevented by the electron degeneracy pressure, a quantum effect that arises from the statistical properties of fermions through the Pauli exclusion principle. In this article, we present a simple theoretical model for the structure of white dwarfs and discuss some of its applications in astrophysics.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Marco Moriconi
creator: Rodrigo Negreiros
rights: Copyright (c) 2025 Marco Moriconi, Rodrigo Negreiros https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 139
ending page: 151
doi: 10.47456/Cad.Astro.v6n2.49837

Density functional theory: foundations, challenges, and new horizons in the quantum mechanics of atoms, molecules, and solids
type: item
description: On the centennial of quantum mechanics, this work provides a comprehensive review of the theoretical foundations, current challenges, and emerging frontiers in many-body quantum theory, with particular emphasis on Density Functional Theory (DFT), the GW approximation, and their applications in fields such as astronomy and in novel methodologies grounded in Machine Learning (ML) and evolutionary algorithms. By surveying these diverse applications, from astrophysical systems to artificial intelligence, we underscore the inherently interdisciplinary character of this sixty-year-old framework, which continues to be indispensable for advancing our understanding of the properties of matter and for driving technological innovation.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Matheus Barbosa
creator: Leonardo Villegas-Lelovsky
creator: Alberto Torres
creator: Alan Barros de Oliveira
creator: Amaury Souza
creator: Breno R. L. Galvao
creator: Alexandre R. Rocha
creator: Mário S. C. Mazzoni
creator: Matheus Matos
rights: Copyright (c) 2025 Matheus S. Barbosa, Leonardo Villegas-Lelovsky, Alberto Torres , Alan B. de Oliveira, Amaury de Melo Souza, Breno R. L. Galvao, Alexandre R. Rocha, Mário S. C. Mazzoni, Matheus J. S. Matos https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 110
ending page: 138
doi: 10.47456/Cad.Astro.v6n2.49847

Revisiting Duhem: quasars, cosmology, and the tripartite relationship between theories and experiments.
type: item
description: This essay examines the work of the physicist and philosopher of science Pierre Duhem, whose contributions anticipated by more than fifty years several elements later developed in the epistemologies of Popper, Kuhn, and Lakatos. Duhem argued that scientific progress cannot be adequately described as a simple confrontation between theory and experiment. Instead, it involves a tripartite relationship in which competing theories are compared in light of experimental results, with experiments functioning mainly as a basis for comparison and theory choice. To illustrate Duhem’s theses, we discuss the early detections of quasars and their role in the cosmological debate between the Big Bang and the Steady State theories. The observed variation in the number of quasars over cosmic time indicated that the Universe is a dynamically evolving physical system, a feature predicted by the Big Bang theory but not explained within the Steady State model.
subject: Divulgação Científica, Ciência e Sociedade
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Danilo Rodrigues
creator: Jose Chiappin
creator: Ramachrisna Teixeira
creator: Jojomar Lucena da Silva
rights: Copyright (c) 2026 Danilo Rodrigues, Jose Raymundo Novaes Chiappin, Ramachrisna Teixeira, Jojomar Lucena da Silva https://creativecommons.org/licenses/by/4.0
date: 2026-04-09
publication date: 2026-04-09
starting page: 97
ending page: 111
doi: 10.47456/Cad.Astro.v7n1.49709

Quantum effects in curved spaces: from the particle concept to field theory
type: item
description: Quantum field theory is currently the most accurate description of matter, but this framework is the result of a long evolution of the concept of particle in physics. In this article, we trace this development: starting from classical mechanics, where particles are treated as point-like objects; moving to quantum mechanics, where they are described as waves associated with probabilities; and finally arriving at quantum field theory, where particles appear as excitations of fundamental fields. We show that in curved or expanding spacetimes, the definition of a particle is no longer unique: different observers can adopt different vacuum states and consequently identify particles in different ways. We also discuss the role of the quantum vacuum and its connection to the cosmological constant problem, one of the major open questions in contemporary physics. By connecting quantum theory, general relativity, and cosmology, the article addresses both the progress achieved and the conceptual challenges that remain in describing the universe at its most extreme scales.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Sandro Dias Pinto Vitenti
rights: Copyright (c) 2025 Sandro Dias Pinto Vitenti https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 27
ending page: 41
doi: 10.47456/Cad.Astro.v6n2.49699

The problem of time in gravitation and cosmology
type: item
description: IIn this outreach review, we discuss key concepts of quantum theory and their application to the construction of a quantum theory of gravitation and cosmology. Of special significance is the problem of time: how can we understand the evolution of a quantum Universe if there is no classical variable that represents an absolute time?
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Leonardo Chataignier
rights: Copyright (c) 2025 Leonardo Chataignier https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 87
ending page: 109
doi: 10.47456/Cad.Astro.v6n2.49554

Tests of quantum gravity in the laboratory
type: item
description: This work introduces some of the main topics related to recent efforts to conduct experiments that prove the quantum nature of gravity in the laboratory. An overview of the conceptual problems involved will be presented, describing the most well-known theories as well as discussing some of the most relevant approaches for laboratory experiments, such as the Diósi-Penrose decoherence model. Using the formalism of canonical quantization of linearized gravity, it is demonstrated how predictions are beginning to be extracted from the known theories for a regime that is still little explored experimentally. Next, some of the main experimental proposals in the literature are discussed, particularly the possibility of generating entanglement between two massive sources in a state of quantum superposition and the tests involving optomechanical systems. The conclusions list open problems related to traditional methods of gravity quantization in the low-energy regime and discuss the most promising experimental paths to test predictions that could confirm the quantum nature of the gravitational field.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Francisco Bento Lustosa
rights: Copyright (c) 2025 Francisco Bento Lustosa https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 42
ending page: 61
doi: 10.47456/Cad.Astro.v6n2.49482

The black hole information paradox
type: item
description: In 1974, a discovery shook the scientific community. Stephen Hawking showed that, when quantum mechanics is taken into account, black holes are not black but emit thermal radiation, as measured by stationary observers far away from the black hole. Since then, the resulting process of black hole evaporation has sparked a debate that divides physicists to this day: what happens to the information that falls into the black hole? In this article, we will review the process of black hole evaporation, showing in particular that there is nothing paradoxical about the loss of information in the end. We will then examine the alternatives to information loss, highlighting their pros and cons.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: André G. S. Landulfo
rights: Copyright (c) 2025 André G. S. Landulfo https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 72
ending page: 86
doi: 10.47456/Cad.Astro.v6n2.49480

Quantum effects in gravitation and gravitational analogues
type: item
description: Modern physics reveals that the quantum vacuum, far from being an absolutely empty space, exhibits peculiar properties when analyzed in a curved spacetime, such as in the vicinity of black holes. The interaction between quantum fields and spacetime geometry is formally described by Quantum Field Theory in Curved Spacetimes, which treats gravitational effects as classical manifestations of spacetime curvature, as established by General Relativity. Hawking radiation, for instance, describes how quantum fluctuations near a black hole lead to thermal emission to the exterior, resulting in its gradual evaporation. Another example is the Unruh effect, which predicts that an accelerated observer perceives a thermal bath of radiation in a region where an inertial observer would see only the particle vacuum. However, these phenomena are difficult to detect directly due to the extreme scales involved, which result in thermal emissions of extremely low temperatures. To overcome this limitation, scientists have developed analogue models of gravity. These analogue models are systems (for example, fluid flows and ultracold gases) that reproduce, in the laboratory, conditions equivalent to curved spacetimes. Experiments based on these models allow us to study how spacetime structure influences the quantum behavior of the vacuum, bridging theory and observation and deepening our understanding of the interface between gravity and quantum mechanics.
subject: Seção Temática
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Lucas Tobias de Paula
creator: Murillo Spadin Domingues
creator: Maurício Richartz
rights: Copyright (c) 2025 Lucas Tobias de Paula, Murillo Spadin Domingues, Maurício Richartz https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 62
ending page: 71
doi: 10.47456/Cad.Astro.v6n2.49451

A forgotten Pioneer: Guido Beck and the prediction of gravitational waves
type: item
description: In 1925, the young Austrian physicist Guido Beck obtained the first exact solution to the equations of general relativity that exhibits the phenomenon of energy transport via gravitational waves. Despite its relevance and pioneering character, Beck's work remained unknown to the physics community for decades. Here we present a translation into Portuguese of the original article, written in German, in which Beck presents these results, along with an overview of the early years of his career, when he worked in the field of general relativity.
subject: Textos Clássicos
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Alexandre S. da Cruz
creator: Rafael Velloso
creator: Antonio Augusto Passos Videira
rights: Copyright (c) 2025 Alexandre Sampaio da Cruz, Rafael Velloso, Antonio Augusto Passos Videira https://creativecommons.org/licenses/by/4.0
date: 2025-10-29
publication date: 2025-10-29
starting page: 199
ending page: 215
doi: 10.47456/Cad.Astro.v6n2.49164

The rebirth of general relativity: theses and historiographical perspectives
type: item
description: In this article, we discuss the thesis, common among physicists and historians, that, after three decades of stagnation, there was a “renaissance” of interest in general relativity in the 1950s and 1960s. We present two versions of this thesis: one places the shift in the 1950s, following the first conferences dedicated to general relativity, and the other identifies the shift in the 1960s, due to advancements in astrophysics. We review the main arguments supporting this thesis by physicists and historians, recall some of the criticisms it has received, and analyze the key historical evidence that emerges in this historiographical debate. Finally, we reflect on the validity of this thesis and on the current challenges in research on the history of general relativity.
subject: Divulgação Científica, Ciência e Sociedade
  topic: section
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
subject: Array
  topic: keywords
creator: Juliana Correia Ferreira
creator: Juliana Youssef
creator: Thiago Hartz
rights: Copyright (c) 2025 Juliana Correia Ferreira, Juliana Youssef, Thiago Hartz https://creativecommons.org/licenses/by/4.0
date: 2025-04-03
publication date: 2025-04-03
starting page: 95
ending page: 112
doi: 10.47456/Cad.Astro.v6n1.46016