All Outputs (25)

Sub-percent constraints on cosmological temperature evolution (2016)
Journal Article
Avgoustidis, A., Genova-Santos, R. .., Luzzi, G., & Martins, C. (2016). Sub-percent constraints on cosmological temperature evolution. Physical Review D - Particles, Fields, Gravitation and Cosmology, 93(4), Article 043521. https://doi.org/10.1103/PhysRevD.93.043521

The redshift dependence of the cosmic microwave background temperature is one of the key cosmological observables. In the standard cosmological model one has T (z) = T0(1 + z), where T0 is the present-day temperature. Deviations from this behavior wo... Read More about Sub-percent constraints on cosmological temperature evolution.

Zipping and unzipping in string networks: dynamics of Y-junctions (2015)
Journal Article
Avgoustidis, A., Pourtsidou, A., & Sakellariadou, M. (2015). Zipping and unzipping in string networks: dynamics of Y-junctions. Physical Review D, 91(2), Article 025022. https://doi.org/10.1103/PhysRevD.91.025022

We study, within the Nambu-Goto approximation, the stability of massive string junctions under the influence of the tensions of three strings joining together in a Y-type configuration. The relative angle β between the strings at the junction is in g... Read More about Zipping and unzipping in string networks: dynamics of Y-junctions.

Is the universe transparent? (2015)
Journal Article
Liao, K., Avgoustidis, A., & Li, Z. (2015). Is the universe transparent?. Physical Review D, 92(12), Article 123539. https://doi.org/10.1103/PhysRevD.92.123539

We present our study on cosmic opacity, which relates to changes in photon number as photons travel from the source to the observer. Cosmic opacity may be caused by absorption or scattering due to matter in the Universe, or by extragalactic magnetic... Read More about Is the universe transparent?.

Cosmological effects of scalar-photon couplings: dark energy and varying-α models (2014)
Journal Article
Avgoustidis, A., Martins, C., Monteiro, A., Vielzeuf, P., & Luzzi, G. (2014). Cosmological effects of scalar-photon couplings: dark energy and varying-α models. Journal of Cosmology and Astroparticle Physics, 2014(6), https://doi.org/10.1088/1475-7516/2014/06/062

We study cosmological models involving scalar fields coupled to radiation and discuss their effect on the redshift evolution of the cosmic microwave background temperature, focusing on links with varying fundamental constants and dynamical dark energ... Read More about Cosmological effects of scalar-photon couplings: dark energy and varying-α models.

Evolution of semilocal string networks: large-scale properties (2014)
Journal Article
Achúcarro, A., Avgoustidis, A., Leite, A., Lopez-Eiguren, A., Martins, C., Nunes, A., & Urrestilla, J. (2014). Evolution of semilocal string networks: large-scale properties. Physical Review D, 89(6), Article 063503. https://doi.org/10.1103/PhysRevD.89.063503

We report on a detailed numerical study of the evolution of semilocal string networks, based on the largest and most accurate field theory simulations of these objects to date. We focus on the large-scale network properties, confirming earlier indica... Read More about Evolution of semilocal string networks: large-scale properties.