Cosmic Rhythms

Session

Flash talks and Poster session II

11 Sept 2026, 14:30

Auditório Ministro João Alberto Lins e Barros (CBPF)

44. A novel framework for light-cone perturbations

Dr Matheus Rodrigues Medeiros Silva

11/09/2026, 14:30

Poster + Fireslide

In this talk, we present a novel framework to compute gauge-invariant cosmological observables, such as the luminosity distance–redshift relation, the redshift drift, and the relation between galaxy number counts and luminosity distance. Our approach is based on constructing first- and second-order perturbations around a homogeneous and isotropic background within geodesic light-cone (GLC)...

12. Effective Phantom Behavior from Dark Sector Interactions in a Hybrid Scalar-Field Model

Kaynan Pompeu (IFT - Unesp)

11/09/2026, 14:32

Poster + Fireslide

Recent data has pointed out that dark energy may not be consistent with a cosmological constant. Combined datasets increasingly indicate that its equation of state may exhibit dynamical behavior, potentially crossing the “phantom divide” ($w < -1$) at low redshifts. This feature has been discussed as one possible aspect of the so-called BAO tension and is difficult to reproduce within simple...

26. Investigating Degeneracies in the Effective Field Theory of Interacting Dark Energy

Ricardo Alexandre Fernandes Filho (Universidade federal do Espírito Santo)

11/09/2026, 14:34

Poster + Fireslide

The nature of dark energy and dark matter remains one of the central open problems in modern cosmology. In this context, the Effective Field Theory (EFT) of dark energy provides a general and systematic framework to investigate departures from the standard cosmological model and to describe possible interactions in the dark sector. In this work, we study interacting dark energy scenarios...

46. Implications of Oscillatory Gravitational Strength for the H0 and S8 Tensions

Lucas Patric Cardoso Leão (Universidade Federal de Minas Gerais)

11/09/2026, 14:36

Poster + Fireslide

The $\Lambda$CDM cosmological model faces persistent challenges, most notably the statistically significant discrepancies in the Hubble constant ($H_0$) and the amplitude of matter fluctuations ($S_8$). In this context, we study the cosmological effects of a Bergmann-Wagoner scalar-tensor model with cold dark matter (ST-CDM for short) featuring an oscillatory gravitational strength,...

53. Observational Confrontation of Energy Condition Bounds in f(R) Theories: an Application to the Hu-Sawicki Model

Lucca Lopes Dias Santos (Universidade de Brasília)

11/09/2026, 14:38

Poster + Fireslide

The dark energy component in the Standard Model of Cosmology accounts for the recent accelerated expansion of the universe. An alternative approach involves geometric modifications to general relativity, leading to modified theories of gravity. When applied to a gravity theory, energy conditions impose constraints on the Ricci and energy-momentum tensors, which translate into inequalities....

31. Statistical Analysis of the Cosmic Web Skeleton in different Cosmologies

Laura de Carvalho (Universidade Federal da Bahia)

11/09/2026, 14:40

Poster + Fireslide

The large-scale distribution of matter in the Universe is organized into a complex network known as the cosmic web, where filaments act as the primary bridges for mass transport and connectivity between clusters. This work proposes a characterization of the filamentary network using the Quijote suite of n-body simulations, which allows for the exploration of a wide range of cosmological...

88. Cosmological Constraints from the Galaxy Power Spectrum with Model Independence

Mr Leonam Barradas Coelho (OV)

11/09/2026, 14:42

Poster + Fireslide

The galaxy power spectrum is a powerful probe of the large-scale structure of the universe and allows us to obtain constraints for many cosmological parameters. However, standard analyses assume a cosmological model to define the theoretical linear power spectrum shape, which makes the analysis model dependent. The recently proposed FreePower method seeks to produce model independent analyses...

38. Forecasting cosmological constraints from the velocity angular power spectrum of type Ia supernovae.

João Pedro Bonifácio (Universidade Federal do Rio de Janeiro)

11/09/2026, 14:44

Poster + Fireslide

Type Ia Supernovae (SNIa) are fundamental distance indicators for cosmology thanks to their nature as standardizable candles. The Rubin Observatory Legacy Survey of Space and Time will provide a sample of millions of SNIa due to its large sky coverage and high cadence. Apart from the direct measurement of cosmological parameters with traditional methods of SNIa analysis, this sample enables...

85. Peculiar velocities as a probe of LSS

Mr Camilo Crisman (CBPF)

11/09/2026, 14:46

Large-scale structure

Poster + Fireslide

Type Ia supernova magnitudes are correlated due to their peculiar velocities, which are sourced by the large-scale structure of the Universe. This effect provides a way to probe the growth of structures and the distribution of matter, with strong potential in light of upcoming, larger supernova catalogues. In this talk, I analyze the Pantheon+ and DES-Y5 samples in combination with Planck CMB...

77. Dark Siren Cosmology

Tatiane de Paula Moraes (Federal University of Espirito Santo)

11/09/2026, 14:48

Poster + Fireslide

A decade after the first gravitational-wave detection, the field has rapidly expanded, opening new opportunities to address key cosmological problems such as the Hubble tension and the study of large-scale structure. As the number of detections continues to increase, the development of robust and efficient computational tools has become essential. In this work, we focus on dark siren...