Navegação por Autor "Nunes, Rafael da Costa"

Resultados 1-17 de 17

    • Baryon acoustic scale at zeff = 0.166 with the SDSS blue galaxies 

      Avila, Felipe; Carvalho Filho, Edilson de; Bernui, Armando; Lima, Hanna Gabrielle Pereira; Nunes, Rafael da Costa (2024) [Artigo de periódico]
      The baryon acoustic oscillations (BAOs) phenomenon provides a unique opportunity to establish a standard ruler at any epoch in the history of the evolving universe. The key lies in identifying a suitable cosmological tracer ...

    • A consistent view of interacting dark energy from multiple CMB probes 

      Zhai, Yuejia; Giarè, William; Bruck, Carsten van de; Di Valentino, Eleonora; Mena Requejo, Olga; Nunes, Rafael da Costa (2023) [Artigo de periódico]
      We analyze a cosmological model featuring an interaction between dark energy and dark matter in light of the measurements of the Cosmic Microwave Background released by three independent experiments: the most recent data ...

    • Cosmological singularities in f(T,φ) gravity 

      Trivedi, Oem; Khlopov, Maxim Yu; Levi-Said, Jackson; Nunes, Rafael da Costa (2023) [Artigo de periódico]
      The pursuit of understanding the mysteries surrounding dark energy has sparked significant interest within the field of cosmology. While conventional approaches, such as the cosmological constant, have been extensively ...

    • Desenvolvimento de um emulador para o espectro de potência da matéria para modelos de interação no setor escuro 

      Neff, João Pedro Caccia (2024) [Trabalho de conclusão de graduação]
      Este trabalho propõe o desenvolvimento de um emulador para o espectro de potência da matéria utilizando redes neurais implementadas com a biblioteca CosmoPower. O treinamento do emulador é baseado em dados gerados por ...

    • A double take on early and interacting dark energy from JWST 

      Forconi, Matteo; Giarè, William; Mena Requejo, Olga; Ruchika, Ruchika; Di Valentino, Eleonora; Melchiorri, Alessandro; Nunes, Rafael da Costa (2024) [Artigo de periódico]
      The very first light captured by the James Webb Space Telescope (JWST) revealed a population of galaxies at very high redshifts more massive than expected in the canonical ΛCDM model of structure formation. Barring, among ...

    • Exploring modified gravity: constraints on the μ and parametrization with WMAP, ACT, and SPT 

      Andrade, Uendert; Capistrano, Abraão J. S.; Di Valentino, Eleonora; Nunes, Rafael da Costa (2024) [Artigo de periódico]
      The cosmic acceleration problem remains one of the most significant challenges in cosmology. One of the proposed solutions to this problem is the modification of gravity on large scales. In this paper, we explore the ...

    • Forecasting constraints on deviations from general relativity in f ( Q ) gravity with standard sirens 

      D'Agostino, Rocco; Nunes, Rafael da Costa (2022) [Artigo de periódico]
      In this work, we explore how modified gravity theories based on the nonmetricity scalar, known as fðQÞ gravity, affect the propagation of gravitational waves from inspiraling of binary systems. We discuss forecast constraints ...

    • Inferring S8(z) and γ (z) with cosmic growth rate measurements using machine learning 

      Avila, Felipe; Bernui, Armando; Bonilla, Alexander; Nunes, Rafael da Costa (2022) [Artigo de periódico]
      Measurements of the cosmological parameter S8 provided by cosmic microwave background and large scale structure data reveal some tension between them, suggesting that the clustering features of matter in these early and ...

    • Late-time constraints on interacting dark energy : analysis independent of H0, rd, and MB 

      Benisty, David; Pan, Supriya; Staicova, Denitsa; Di Valentino, Eleonora; Nunes, Rafael da Costa (2024) [Artigo de periódico]
      We investigated a possible interaction between cold dark matter and dark energy, corresponding to a well-known interacting dark energy model discussed in the literature within the context of resolving the Hubble tension. ...

    • Late-time interacting cosmologies and the Hubble constant tension 

      Gariazzo, Stefano; Di Valentino, Eleonora; Mena Requejo, Olga; Nunes, Rafael da Costa (2022) [Artigo de periódico]
      In this manuscript we reassess the potential of interacting dark matter–dark energy models in solving the Hubble constant tension. These models have been proposed but also questioned as possible solutions to the H0 problem. ...

    • New cosmological constraints on f(T) gravity in light of full Planck-CMB and type Ia supernovae data 

      Kumar, Suresh; Nunes, Rafael da Costa; Yadav, Priya (2023) [Artigo de periódico]
      We investigate two new observational perspectives in the context of torsional gravitational modification of general relativity, i.e., the f(T) gravity: (i) We use Pantheon data of type Ia supernovae motivated by a time ...

    • New tests of dark sector interactions from the full-shape galaxy power spectrum 

      Nunes, Rafael da Costa; Vagnozzi, Sunny; Kumar, Suresh; Di Valentino, Eleonora; Mena Requejo, Olga (2022) [Artigo de periódico]
      We explore the role of redshift-space galaxy clustering data in constraining nongravitational interactions between dark energy (DE) and dark matter (DM), for which state-of-the-art limits have so far been obtained from ...

    • Propriedades físicas da matéria escura e energia escura mediante simulações de N-corpos 

      Neff, João Pedro Caccia (2024) [Resumo publicado em evento]

    • Reconstructing the growth index γ with Gaussian processes 

      Oliveira, Fernanda Araujo de; Avila, Felipe; Bernui, Armando; Bonilla, Alexander; Nunes, Rafael da Costa (2024) [Artigo de periódico]
      Alternative cosmological models have been proposed to alleviate the tensions reported in the concordance cosmological model, or to explain the current accelerated phase of the universe. One way to distinguish between General ...

    • Restrições observacionais em uma transição tardia como uma solução para a tensão de Hubble 

      Souza, Mateus Scherer de (2024) [Resumo publicado em evento]

    • Testing beyond-Kerr spacetimes with GWTC-3 

      Santos, Rafael Mancini; Nunes, Rafael da Costa; Araujo, José Carlos Neves de (2024) [Artigo de periódico]
      The Kerr spacetime is a fundamental solution of general relativity (GR), describing the gravitational field around a rotating, uncharged black hole (BH). Kerr spacetime has been crucial in modern astrophysics and it serves ...

    • The state of the dark energy equation of state circa 2023 

      Escamilla, Luis A.; Giarè, William; Di Valentino, Eleonora; Nunes, Rafael da Costa; Vagnozzi, Sunny (2024) [Artigo de periódico]
      We critically examine the state of current constraints on the dark energy (DE) equation of state (EoS) w. Our study is motivated by the observation that, while broadly consistent with the cosmological constant value w = ...