# Resolving Hubble Tension with New Gravitational Scalar Tensor Theories

Banerjee S, Petronikolou M, Saridakis EN (2023)

**Publication Type:** Conference contribution

**Publication year:** 2023

### Journal

**Publisher:** Sissa Medialab Srl

**Book Volume:** 436

**Conference Proceedings Title:** Proceedings of Science

**Event location:** Corfu, GRC

### Abstract

We investigate the cosmological applications of new gravitational scalar-tensor theories and we analyze them in the light of H0 tension. In these theories the Lagrangian contains the Ricci scalar and its first and second derivatives in a specific combination that makes them free of ghosts, thus corresponding to healthy bi-scalar extensions of general relativity. We examine two specific models, and for particular choices of the model parameters we find that the effect of the additional terms is negligible at high redshifts, obtaining a coincidence with ΛCDM cosmology, however as time passes the deviation increases and thus at low redshifts the Hubble parameter acquires increased values (H0 ≈ 74km/s/Mpc) in a controlled way. The mechanism behind this behavior is the fact that the effective dark-energy equation-of-state parameter exhibits phantom behavior, which implies faster expansion, which is one of the theoretical requirements that are capable of alleviating the H0 tension. Lastly, we confront the models with Cosmic Chronometer (CC) data showing full agreement within 1σ confidence level.

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### How to cite

**APA:**

Banerjee, S., Petronikolou, M., & Saridakis, E.N. (2023). Resolving Hubble Tension with New Gravitational Scalar Tensor Theories. In *Proceedings of Science*. Corfu, GRC: Sissa Medialab Srl.

**MLA:**

Banerjee, Shreya, Maria Petronikolou, and Emmanuel N. Saridakis. "Resolving Hubble Tension with New Gravitational Scalar Tensor Theories." *Proceedings of the Corfu Summer Institute "22nd Hellenic School and Workshops on Elementary Particle Physics and Gravity", CORFU 2022, Corfu, GRC* Sissa Medialab Srl, 2023.

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