# Astrophysics and Cosmology

This group gathers researchers working on astrophysics and cosmology topics. It covers theoretical, computational and observational skills, potentiating synergies between them to tackle a number of problems of current interest in the field. The main research areas are the physics of white dwarfs, neutron stars and black holes, the equation of state of dense hadronic matter, radio astronomy, detection and characterisation of exoplanets, dynamics of stellar and planetary systems, celestial mechanics, computational astrophysics, interplay between particle and gravitational physics, the origin of dark matter, dark energy, inflation, and the baryon asymmetry.

## Current projects

## Previous projects

## Recent Publications

## Papers

### International Journals

1 - Bosonic dark matter in neutron stars and its effect on gravitational wave signal

D. R. Karkevandi, S. Shakeri, Violetta Sagun, O. Ivanytskyi

Phys. Rev. D **105**, 023001 (2022)

2 - Evaporating primordial black holes, the string axiverse, and hot dark radiation

Marco Calzà, John March-Russell, João G. Rosa

Submitted not yet accepted (2022)

3 - The neutron star outer crust equation of state: a machine learning approach

Murarka Utsav Anil, Kinjal Banerjee, Tuhin Malik, Constança Providência

JCAP **01 (2022) 01, 045**, 045 (2022)

4 - Spin in a planar relativistic fermion problem

A.S.de Castro, P. Alberto

Phys. lett., A **404**, 127412 (2021)

5 - Central configurations of the five-body problem with two isosceles triangles

Antonio Carlos Fernandes, Luis Fernando Mello, Bráulio Garcia, Lucas Ruiz dos Santos

J. Appl. Math. Phys. **72** (2021)

6 - Neutron stars within the Bogoliubov quark-meson coupling model

Aziz Rabhi, Constança Providência, Steven A. Moszkowski, João da Providência, Henrik Bohr

Phys. Rev. C **103**, 035811 (2021)

7 - Radio astronomy and Space science in Azores: Enhancing the Atlantic VLBI infrastructure cluster

D Barbosa, B Coelho, S Anton, M Bergano, T Boekholt, ACM Correia, D Maia, J Pandeirada, V Ribeiro, J Adams, JP Barraca, D Gomes, B Morgado

Adv. Space Res. **68(7)**, 3064-3078 (2021)

8 - Thermal production of sexaquarks in heavy-ion collisions

D. Blaschke, L. Bravina, K. Bugaev, G. R. Farrar, B. Grinyuk, O. Ivanytskyi, S. Kabana, S. V. Kuleshov, I. K. Potashnikova, Violetta Sagun, A. Taranenko, O. V. Vitiuk, E. Zabrodin, X. Zhang, D. Zhou

Intern. J. Mod. Phys. A **36**, 2141005 (2021)

9 - Revisiting the analysis of HW Virginis eclipse timing data. I. A frequentist data modeling approach and a dynamical stability analysis

Esmer, E.M., O. Baştürk, T.C. Hinse, S.O. Selam, ACM Correia

Astron. Astrophys. **648**, A85 (2021)

10 - A Nonequilibrium Information Entropy Approach to Ternary Fission of Actinides

G. Röpke, J. B. Natowitz, H. Pais

Phys. Rev. C **103**, L061601 (2021)

11 - Strong magnetic fields: neutron stars with an extended inner crust

Helena Pais, Bruno Bertolino, Jianjun Fang, Xiaopeng Wang, Constança Providência

Eur. Phys. J. A **57**, 193-1-193-9 (2021)

12 - An analytical model for tidal evolution in co-orbital systems. I. Application to exoplanets

J. Couturier, P. Robutel, A.C.M. Correia

Celest. Mech. Dyn. Astron. **133(8)**, 37 (2021)

13 - Phase diagram for strongly interacting matter in the presence of a magnetic field using the Polyakov–Nambu–Jona-Lasinio model with magnetic field dependent coupling strengths

João Moreira, Pedro Costa, Tulio E. Restrepo,

Eur. Phys. J. A **57**, 123-10 (2021)

14 - Induced surface and curvature tension equation of state for hadron resonance gas in finite volumes and its relation to morphological thermodynamics

K. A. Bugaev , O. V. Vitiuk , B. E. Grinyuk , P. P. Panasiuk , N. S. Yakovenko , E. S. Zherebtsova , Violetta Sagun , O. I. Ivanytskyi , L. V. Bravina , D. B. Blaschke , S. Kabana , S. V. Kuleshov , A. V. Taranenko , E. E. Zabrodin and G. M. Zinovjev

Intern. J. Mod. Phys. A **36**, No. 34n35, 2141009 (2021)

15 - Six transiting planets and a chain of Laplace resonances in TOI-178

A. Leleu, Y. Alibert, N.C. Hara, M.J. Hooton, T.G. Wilson, P. Robutel, J.-B. Delisle, J. Laskar, S. Hoyer, C. Lovis, E.M. Bryant, E. Ducrot, J. Cabrera, L. Delrez, J.S. Acton, V. Adibekyan, R. Allart, C. Allende Prieto, ACM Correia

Astron. Astrophys. **649**, A26 (2021)

16 - Faint objects in motion: the new frontier of high precision astrometry

Malbet, F., Boehm, C., Alexandre C. M. Correia, et. al.

Exp. Astron. **51(3)**, 845-886 (2021)

17 - Towards a reliable effective field theory of inflation

Mar Bastero-Gil, Arjun Berera, Rudnei O. Ramos, JG Rosa

Phys. Lett. B **813**, 136055 (2021)

18 - New constraints on the planetary system around the young active star AU Mic. Two transiting warm Neptunes near mean-motion resonance

E. Martioli, G. Hébrard, A.C.M. Correia, J. Laskar, Lecavelier des Etangs

Astron. Astrophys. **649**, A177 (2021)

19 - Warm Inflation, Neutrinos and Dark matter: a minimal extension of the Standard Model

Miguel Levy, JG Rosa, Luís B. Ventura

J. High Energy Phys.. **12**, 176 (2021)

20 - Thermal evolution of relativistic hyperonic compact stars with calibrated equations of state

Morgane Fortin, Adriana R. Raduta, Sidney Avancini, Constança Providência

Phys. Rev. D **103**, 083004 (2021)

21 - Unveiling the nuclear matter EoS from neutron star properties: a supervised machine learning approach

Márcio Ferreira, Constança Providência

J. Cosmol. Astropart. Phys **7**, 011 (2021)

22 - Constraints on high density equation of state from maximum neutron star mass

Márcio Ferreira, Constança Providência

Phys. Rev. D **104**, 063006 (2021)

23 - Crust-core transition of a neutron star: effect of the temperature under strong magnetic fields

Márcio Ferreira, Aziz Rabhi, Constança Providência

Eur. Phys. J. A **57**, 263 (2021)

24 - Hybrid stars with large strange quark cores constrained by GW170817

Márcio Ferreira, Renan Câmara Pereira, Constança Providência )

Phys. Rev. D **103**, 123020 (2021)

25 - Critical properties of calibrated relativistic mean-field models for the transition to warm, nonhomogeneous nuclear and stellar matter

Olfa Boukari, Helena Pais, Sofija Antić, Constança Providência

Phys. Rev. C **103**, 055804 (2021)

26 - Analytic continuation of nucleon electromagnetic form factors in the time-like region

P. Alberto , A. Drago, A. Mangoni, S. Moretti, S. Pacetti

J. Phys. G: Nucl. Part. Phys. **48**, 085007 (2021)

27 - Determination of the symmetry energy from the neutron star equation of state

Pedro Barata de Tovar, Márcio Ferreira, Constança Providência

Phys. Rev. D **104**, 123036 (2021)

28 - Binding energy shifts from heavy-ion experiments in a nuclear statistical equilibrium model

S. Mallik, H. Pais, F. Gulminelli

Eur. Phys. J. A **27**, 262 (2021)

29 - Thermal evolution of neutron stars described within the equation of state with induced surface tension

S. Tsiopelas, V. Sagun

Astron. Nachrichten **342(1-2)**, 332-336 (2021)

30 - Light hyperclusters and hyperons in low-density hot stellar matter

Tiago Custódio, Helena Pais, Constança Providência

Phys. Rev. C **104**, 035801 (2021)

### Portuguese Journals

31 - Fontanários: brincando com a Física!

Constança Providência

Gazeta de Física **44, fasc 1**, 42-44 (2021)

32 - É eletricidade ou magnetismo?

Constança Providência

Gazeta de Física **Volume 43 / Fascículo 3/4**, 32 (2021)

## Proceedings

### International Conferences

33 - Hybrid stars from a constrained equation of state

Constança Providência, Márcio Ferreira, Renan Pereira

to appear in AIP Conf Proc (2021)

34 - Evaporating primordial black holes, the string axiverse, and hot dark radiation

Marco Calzà

XVI Black Holes Workshop, University of Aveiro (2021)

35 - Kinematic reconstruction of extended theories of gravity at small and intermediate redshifts

Marco Calzà

15th IberiCOS meeting (2021)

## Communications

### Invited

36 - Neutron star properties from a constrained EoS

Constança Providência, Márcio Ferreira, Renan Pereira

vConf21 - A Virtual Tribute to Quark Confinement and the Hadron Spectrum 2021 - 2-6 August 2021 (2021)

37 - On the eccentricity of warm Neptunes

Correia, ACM

1st Planet Systems Day @ IA, February 2, online meeting. (2021)

38 - Evaporating primordial black holes, the string axiverse, and hot dark radiation

Marco Calzà

University of Trento (2021)

### Oral

39 - New SST Optical Sensor of Pampilhosa da Serra: studies on image processing algorithms and multi-filter characterization of Space Debris

Coelho, B., Barbosa, D., Bergano, M., Correia, A.C.M., Freitas, J., Marques, P., Pandeirada, J., Ribeiro, V.

8th European Conference on Space Debris, 20-23 April (online meeting) (2021)

40 - Nonzero eccentricities of warm Neptunes

Correia, A.C.M.

PLATO Mission Conference, 11-15 October (online meeting) (2021)

41 - Asynchronous and chaotic rotation for compact planetary systems

Correia, A.C.M.

Multi-scale (time and mass) dynamics of space objects, 18-22 October, Iasi, Romania (online meeting) (2021)

42 - Acoplamento spin-órbita em sistemas planetários compactos

Correia, A.C.M.

XX Colóquio Brasileiro de Dinâmica Orbital, 6-10 December (online meeting) (2021)

43 - Evolution of the Pluto-Charon binary under tides

Correia, ACM

52nd Annual Meeting of the DDA, 17-21 May, virtual workshop (2021)

44 - Asynchronous and chaotic rotation for compact planetary systems

Correia, ACM

Exoplanets Orbits & Dynamics, 19-22 January, virtual workshop (2021)

45 - Tidal Evolution of the Pluto-Charon-Sun Triple

Correia, ACM

Triple Evolution and Dynamics 3, 22-25 March, virtual workshop (2021)

46 - Local solutions in modified gravity adopting ad hoc ansatz

Marco Calzà

Journal Club, University of Coimbra (2021)

47 - The Axiverse and how to probe it exploiting evaporating primordial black holes.

Marco Calzà

Journal Club, University of Coimbra (2021)

48 - The unified equation of state with induced surface tension consistent with astrophysical, gravitational, high- and low- energy nuclear physics data

Violetta Sagun, O. Ivanytskyi, Constança Providência

at the Virtual Tribute to Quark Confinement and the Hadron Spectrum 2021 - ConfXIV, 2-6 August (2021)

49 - Neutron stars as dark matter probes

Violetta Sagun, O. Ivanytskyi, D. R. Karkevandi, S. Shakeri, I. Lopes

at the Modern Physics of Compact Stars and Relativistic Gravity, Yerevan, Armenia, 27-30 September (2021)

50 - The impact of dark matter on compact stars

Violetta Sagun, O. Ivanytskyi, I. Lopes

The 57 Karpacz Winter School in Theoretical Physics, Karpacz, Poland, 13-19 June (2021)

51 - How neutron stars can help us to constrain dark matter

Violetta Sagun, O. Ivanytskyi, I. Lopes

The Iberian Cosmology Meeting (IberiCOS 2021), University of Coimbra, Coimbra, 29 March - 1 April (2021)

52 - Constraints on the fermionic dark matter from observations of neutron stars

Violetta Sagun, O. Ivanytskyi, I. Lopes

at the Particles and Nuclei International Conference - PANIC2021, online, 5-10 September (2021)

### Poster

53 - Probing dark matter with neutron stars

Violetta Sagun, O. Ivanytskyi, D. R. Karkevandi, S. Shakeri, E. Giangrandi, I. Lopes

at the Gravitational Wave Physics and Astronomy Workshop (GWPAW 2021),
Hannover, Germany, 14-17 December (2021)

## Other

54 - Ceres – o asteroide planeta anão

Correia, A.C.M.

Boletim da Associação dos Pupilos do Exército **262**, 12 (2021)

55 - Observatório SKA

Correia, A.C.M.

Boletim da Associação dos Pupilos do Exército **260**, 12 (2021)

56 - Tooling4G – Minimize the Airflow Generated Noise on Automotive HVAC Systems

J. F. Caseiro, P. Alberto

White Papers – SHAPE Projects PRACE-6IP (2021)

57 - Spontaneous breaking of the Peccei-Quinn symmetry during warm inflation

JG Rosa, Luís B. Ventura

arXiv: 2105.05771 (2021)

58 - Superradiant pion clouds around primordial black holes

Paulo B. Ferraz, Thomas W. Kephart, JG Rosa

arXiv:2004.11303 (2021)