My research interests focus on study the neutron star properties, the strongly interacting matter phase diagram, the deconfinement and liquid-gas phase transitions. Particularly I work on a development of a unified equation of state able to describe strongly interacting matter in all ranges of temperature and baryon density, i.e. heavy-ion collisions and neutron stars.
Research Highlights
- The induced surface tension contribution for the equation of state of
neutron stars
Violetta Sagun, I. Lopes, A. I. Ivanytskyi
Astrophys. J. 871, 157 (2019) - Neutron stars meet constraints from high and low energy nuclear physics
Violetta Sagun, I. Lopes, A. Ivanytskyi
Nuclear Physics A, Proceedings of the ‘XXVIIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2018)’ 982, 883-886 (2019)
Publications [LaTeX]
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 - The effect of self-interacting bosonic dark matter on neutron star properties
E. Giangrandi, Violetta Sagun, O. Ivanytskyi, C. Providência, T. Dietrich
submitted to the APJ (2022)
3 - Numerical simulations of dark matter admixed neutron star binaries
M. Emma, F. Schianchi, Francesco, F. Pannarale, Violetta Sagun, T. Dietrich
Particles 5, 273 (2022)
4 - Colliding and Fixed Target mode in a single experiment - a novel approach to study the matter under new extreme conditions
O. V. Vitiuk, V. M. Pugatch, K. A. Bugaev, N. S. Yakovenko, P. P. Panasiuk, E. S. Zherebtsova, V. M. Dobishuk, S. B. Chernyshenko, B. E. Grinyuk, Violetta Sagun, O. Ivanytskyi
Particles 5, 245 (2022)
5 - 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)
6 - 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)
7 - 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)
8 - Classical excluded volume of loosely bound light (anti) nuclei and their chemical freeze-out in heavy ion collisions
B. E. Grinyuk, K. A. Bugaev, Violetta Sagun, O. I. Ivanytskyi, D. L. Borisyuk, A. S. Zhokhin, G. M. Zinovjev, D. B. Blaschke, L. V. Bravina, E. E. Zabrodin, E. G. Nikonov, G. Farrar, S. Kabana, S. V. Kuleshov, A. V. Taranenko
International Journal of Modern Physics E 29, 2040009 (2020)
9 - Second virial coefficients of light nuclear clusters and their chemical freeze-out in nuclear collisions
K. A. Bugaev, O. V. Vitiuk, B. E. Grinyuk, Violetta Sagun, N. S. Yakovenko, O. I. Ivanytskyi, G. M. Zinovjev, D. B. Blaschke, E. G. Nikonov, L. V. Bravina, E. E. Zabrodin, S. Kabana, S. V. Kuleshov, G. R. Farrar, E. S. Zherebtsova, A. V. Taranenko,
Eur. Phys. J. A 56, 293 (2020)
10 - Neutron stars: New constraints on asymmetric dark matter
O. Ivanytskyi, Violetta Sagun, and I. Lopes
Phys. Rev. D 102, 063028 (2020)
11 - Neutron star cooling within the equation of state with induced surface tension
S. Tsiopelas, Violetta Sagun
Particles 3, 693-705 (2020)
12 - Asteroseismology: radial oscillations of neutron stars with realistic equation of state
Violetta Sagun, I. Lopes G. Panotopoulos
Phys. Rev. D 101, 063025 (2020)
13 - Second look to the Polyakov Loop Nambu-Jona-Lasinio model at finite baryonic density
O. Ivanytskyi, M. Ángeles Pérez-Garcı́a, Violetta Sagun, C. Albertus
Phys. Rev. D 100, 103020 (2019)
14 - The induced surface tension contribution for the equation of state of
neutron stars
Violetta Sagun, I. Lopes, A. I. Ivanytskyi
Astrophys. J. 871, 157 (2019)
15 - On relation between bulk, surface and curvature parts of nuclear
binding energy within the model of hexagonal clusters
Violetta Sagun, K. A. Bugaev, A. I. Ivanytskyi
Phys. Part. Nucl. Lett. 16, No. 6, 671-680 (2019)
Proceedings
International Conferences
16 - Constraints on the fermionic dark matter from observations of neutron stars
Violetta Sagun, E. Giangrandi, O. Ivanytskyi, I. Lopes, K. A. Bugaev
Proceedings of Science (PoS), Proceedings of the Particles and Nuclei International Conference (PANIC2021) 380, 313 (2021)
17 - Chemical freeze-out of light nuclei in high energy nuclear
collisions and resolution of the hyper-triton chemical freeze-out puzzle
K.A. Bugaev, O.V. Vitiuk, B.E. Grinyuk, N.S. Yakovenko, E.S. Zherebtsova, Violetta Sagun, O.I. Ivanytskyi, D.O. Savchenko, L.V. Bravina, D.B. Blaschke, G.R. Farrar, S. Kabana, S.V. Kuleshov, E.G. Nikonov, A.V. Taranenko, E.E. Zabrodin, G.M. Zinovjev
J. Phys.: Conf. Ser., Proceedings of the 5th International Conference on Particle Physics and Astrophysics (ICPPA-2020), 5-9 October 2020, Moscow, Russian Federation 1690, 012123 (2020)
18 - Thermal evolution of neutron stars described within the equation of state with induced surface tension
S. Tsiopelas, Violetta Sagun
Astronomische Nachrichten 342, 332 (2020)
19 - Hard-core Radius of Nucleons within the Induced Surface Tension Approach
K. A. Bugaev, A. I. Ivanytskyi, Violetta Sagun, B. E. Grinyuk, D. O. Savchenko, G. M. Zinovjev, E. G. Nikonov, L. V. Bravina, E. E. Zabrodin, D. B. Blaschke, A. V. Taranenko, L. Turko
Universe, Proceedings of the 7th International Conference on New Frontiers in Physics (ICNFP 2018)) 5(2), 63 (2019)
20 - Possible signals of two QCD phase transitions at NICA-FAIR energies
K. A. Bugaev, A. I. Ivanytskyi, Violetta Sagun, B. E. Grinyuk, D. O. Savchenko, G. M. Zinovjev, E. G. Nikonov, L. V. Bravina, E. E. Zabrodin, D. B. Blaschke, A. V. Taranenko S. Kabana
EPJ Web Conf. 204, 03001 (2019)
21 - On separate chemical freeze-outs of hadrons and light(anti)nuclei in high energy nuclear collisions
K. A. Bugaev, B. E. Grinyuk, A. I. Ivanytskyi, Violetta Sagun, D. O. Savchenko, G. M. Zinovjev, E. G. Nikonov, L. V. Bravina, E. E. Zabrodin, D. B. Blaschke, S. Kabana, A. V. Taranenko
J. Phys.: Conf. Ser., Proceedings of the 4th International Conference on Particle Physics and Astrophysics (ICPPA-2018) 1390, 012038 (2019)
22 - Neutron stars meet constraints from high and low energy nuclear physics
Violetta Sagun, I. Lopes, A. Ivanytskyi
Nuclear Physics A, Proceedings of the ‘XXVIIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2018)’ 982, 883-886 (2019)
Communications
Invited
23 - The impact of dark matter on compact stars and their merger dynamics
Violetta Sagun
Invited seminar at the CENTRA, Instituto Superior Técnico, University of Lisbon, Portugal, 21 July (2022)
24 - Impact of dark matter on compact stars
Violetta Sagun
Invited Theoretical Physics Colloquium hosted by Prof. Igor Shovkovy at the Arizona State University, 29 June (2022)
25 - Thermal evolution of compact stars
Violetta Sagun
Invited seminar at the Institute for Theoretical Physics, University of Wroclaw, Wroclaw, Poland, 29 April (2022)
26 - Impact of dark matter on compact stars and their merger dynamics
Violetta Sagun, Tim Dietrich, Mattia Emma, Edoardo Giangrandi, Oleksii Ivanytskyi, Ilidio Lopes, Francesco Pannarale, Constança Providência, Federico Schianchi
Invited seminar at the Laboratoire de Physique des 2 infinis Irène Joliot-Curie – IJCLab, Université Paris-Saclay, France, 5 November (2022)
27 - Constraints on dark matter from observations of neutron stars and their mergers
Violetta Sagun, Tim Dietrich, Mattia Emma, Edoardo Giangrandi, Oleksii Ivanytskyi, Ilidio Lopes, Francesco Pannarale, Constança Providência, Federico Schianchi
Invited seminar at the Gr@v group, University of Aveiro, Portugal, 19 October (2022)
28 - Probing dark matter with neutron stars
Violetta Sagun, Tim Dietrich, Mattia Emma, Edoardo Giangrandi, Oleksii Ivanytskyi, Ilidio Lopes, Francesco Pannarale, Constança Providência, Federico Schianchi
at the IPA2022: Interplay between Particle and Astroparticle physics 2022, Vienna University of Technology, Vienna, Austria, 5 - 9 September (2022)
29 - Neutron stars meet constraints from astrophysics, gravitation, high- and low- energy nuclear physics
Violetta Sagun
Invited seminar at the Lawrence Berkeley National Laboratory, Berkeley, USA, 7 May (2020)
30 - Neutron stars meet constraints from astrophysics, gravitation, high- and low- energy nuclear physics
Violetta Sagun
Invited seminar at the Monash Centre for Astrophysics (MoCA), Monash University, Melbourne, Australia, 22 May (2020)
31 - Impact of dark matter on the neutron star properties
Violetta Sagun
Invited seminar at the Institute of High Energy Physics (HEPHY), Vienna, Austria, 17 November (2020)
32 - Series of lectures on “Compact stars, equation of state of neutron stars and the NS-NS merger events”
Violetta Sagun
Oslo Winter School “Standard Model, Quantum Chromodynamics, Heavy Ion Collisions”, Skeikampen, Norway, 2 - 12 January (2020)
33 - Thermal production of Sexaquarks in Heavy Ion Collisions
D. Blaschke, L. Bravina, K. Bugaev, G. Farrar, B. Grinyuk, O. Ivanytskyi, S. Kabana, Violetta Sagun, A. Taranenko, E. Zabrodin, X. Zhang and D. Zhou
at the 8-th International Conference on New Frontiers in Physics (ICNFP2019), Kolymbari, Crete, Greece, August 21-29 (2019)
34 - Updated signals of two QCD phase transitions in heavy ion collisions
K. A. Bugaev, Violetta Sagun, B. E. Grinyuk, A. S. Zhokhin, A. I. Ivanytskyi, D. A. Savchenko, G. M. Zinovjev, E. G. Nikonov, L. V. Bravina, E. E. Zabrodin, S. Kabana, D. B. Blaschke and A. V. Taranenko
at the 8-th International Conference on New Frontiers in Physics (ICNFP2019), Kolymbari, Crete, Greece, August 21-29 (2019)
35 - Classical excluded volume of loosely bound light (anti)nuclei and their chemical freeze-out in HIC
K. A. Bugaev, B. E. Grinyuk, A. I. Ivanytskyi, Violetta Sagun, A. S. Zhokhin, D. A. Savchenko, G. M. Zinovjev, E. G. Nikonov, L. V. Bravina, E. E. Zabrodin, S. Kabana, D. B. Blaschke and A. V. Taranenko
at the 8-th International Conference on New Frontiers in Physics (ICNFP2019), Kolymbari, Crete, Greece, August 21-29 (2019)
36 - Neutron stars meet constraints from astrophysics, gravitation, high and low energy nuclear physics
Violetta Sagun
Institute of Theoretical Astrophysics, University of Oslo, Norway, 17 January, (2019)
37 - Unified equation of state consistent with astrophysical, gravitational, high- and low- energy nuclear physics data and its applications
Violetta Sagun
N. Copernicus Astronomical Center, Polish Academy of Sciences, Warsaw, Poland, 11 December (2019)
38 - Dark-matter admixed compact stars and their properties under extreme conditions
Violetta Sagun
Department of Physics, University of Tokyo, Japan, 30 September (2019)
39 - Neutron stars: laboratories for fundamental physics under extreme conditions
Violetta Sagun
Institute of Theoretical Astrophysics, University of Oslo, Norway, 18 January (2019)
40 - Neutron stars meet constraints from astrophysics, gravitation, high and low energy nuclear physics
Violetta Sagun
“Precision Gravity: From the LHC to LISA”, Munich Institute for
Astro- and Particle Physics (MIAPP), Garching, Germany, 26 August - 6 September (2019)
41 - Dark-matter admixed compact stars and their properties under extreme conditions
Violetta Sagun
Department of Physics, University of Tokyo, Japan, 30 September (2019)
Oral
42 - Impact of asymmetric fermionic and bosonic dark matter on neutron star properties
Violetta Sagun, Oleksii Ivanytskyi, Edoardo Giangrandi
at the Institute for Nuclear Theory workshop (INT-20R-1B) “The r-process and the nuclear EOS after LIGO-Virgo’s third observing run”, Institute for Nuclear Theory, Seattle, USA, 23 - 27 May (2022)
43 - Effect of dark matter on observable neutron star’s properties and its discrimination from the strongly interacting matter equation of state
Violetta Sagun, Tim Dietrich, Mattia Emma, Edoardo Giangrandi, Oleksii Ivanytskyi, Ilidio Lopes, Francesco Pannarale, Constança Providência, Federico Schianchi
at the 18th International Conference on QCD in Extreme Conditions (XQCD 2022), Norwegian University of Science and Technology, Trondheim,
Norway, 27 - 29 July (2022)
44 - The effect of dark matter on compact stars and constraints we put on strongly interacting matter at high densities
Violetta Sagun, Tim Dietrich, Mattia Emma, Edoardo Giangrandi, Oleksii Ivanytskyi, Ilidio Lopes, Francesco Pannarale, Constança Providência, Federico Schianchi
at the Institute for Nuclear Theory workshop (INT-22-2b) “Dark Matter in Compact Objects, Stars, and Low-Energy Experiments ”, Institute for Nuclear Theory, Seattle, USA, 1 August - 2 September (2022)
45 - How dark matter affects compact star’s properties and constraints we put on strongly interacting matter at high densities
Violetta Sagun, Tim Dietrich, Mattia Emma, Edoardo Giangrandi, Oleksii Ivanytskyi, Ilidio Lopes, Francesco Pannarale, Constança Providência, Federico Schianchi
at the “XVth Quark Confinement and the Hadron Spectrum” conference, University of Stavanger, Stavanger, Norway, 1 - 6 August (2022)
46 - Bosonic Dark Matter in Neutron Stars and Gravitational Waves
D. R. Karkevandi, S. Shakeri, Violetta Sagun, O. Ivanytskyi
at the Sixteenth Marcel Grossmann Meeting (MG16), online, 5-10 July (2021)
47 - The impact of dark matter on compact stars
Edoardo Giangrandi, Violetta Sagun, Constança Providência, Tim Dietrich
at the 10th IDPASC School - IDPASC (Nazarè, Portugal), online, 6-17 September (2021)
48 - Impact of asymmetric bosonic dark matter on neutron star properties
Edoardo Giangrandi, Violetta Sagun, Oleksii Ivanytskyi, Constança Providência, Tim Dietrich
XII Conference of Young Scientists "Problems of Theoretical Physics" - Bogolyubov Institute for Theoretical Physics (Kyiv, Ukraine), online, 21-23 December (2021)
49 - Probing strongly interacting matter properties with compact objects
Edoardo Giangrandi, Violetta Sagun, Oleksii Ivanytskyi, Constança Providência, Tim Dietrich
at the 21th Zimányi School, Winter Workshop on Heavy-Ion Physics, Budapest, Hungary, 6-10 December (2021)
50 - 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)
51 - 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)
52 - 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)
53 - 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)
54 - 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)
55 - Constraints on the fraction of cold fermionic dark matter particles inside the neutron stars
Violetta Sagun, O. Ivanytskyi, I. Lopes
at the ICPPA - 5th International Conference on Particle Physics and
Astrophysics, 5-9 October (2020)
56 - Dark-matter admixed neutron stars
Violetta Sagun, O. Ivanytskyi, I. Lopes
at the IWARA2020 Video Conference - 9th International Workshop on Astronomy and Relativistic Astrophysics, 6-12 September (2020)
57 - Dark matter effect on the neutron star properties
Violetta Sagun, O. Ivanytskyi, I. Lopes
The 56 Karpacz Winter School in Theoretical Physics, Karpacz, Poland, 24 - 28 February (2020)
58 - Understanding the Neutron Star Physics with the SKA
Violetta Sagun
workshop “Multi-messenger astronomy with SKA precursors and
pathfinders, a capacity building workshop”, Aveiro, Portugal, 12-15 May (2019)
59 - Dark-matter admixed compact stars and their properties under extreme conditions
Violetta Sagun, A. I. Ivanytskyi, I. Lopes
Young Scientists Conference “Problems of Theoretical Physics”, Kyiv,
Ukraine, 23 - 24 December (2019)
60 - Unified equation of state consistent with astrophysical, gravitational, high- and low- energy nuclear physics data
Violetta Sagun, I. Lopes, A. I. Ivanytskyi
workshop “Neutron stars and their environments” (MODE-SNR-PWN), Orléans, France, 8-10 April (2019)
61 - Equation of state of neutron stars consistent with astrophysical,low- and high-energy nuclear physics data and its applications
Violetta Sagun, I. Lopes, A. I. Ivanytskyi, G. Panotopoulos
PHAROS Conference 2019: the multi-messenger physics and astrophysics of neutron stars, Platja d’ Aro, Spain, 22-26
April (2019)
62 - Astrophysical constraints on the dark matter core inside the neutron stars
Violetta Sagun, O. Ivanytskyi, I. Lopes
XIX National Meeting of Astronomy and Astrophysics (ENAA), Instituto Superior Tecnico, Lisbon, Portugal, 12 - 13 September (2019)
63 - Unified equation of state consistent with astrophysical, gravitational, high- and low- energy nuclear physics data
Violetta Sagun, O. Ivanytskyi, I. Lopes
International workshop “Multi-Messenger Astrophysics in the Gravitational Wave Era”, Yukawa Institute for Theoretical Physics, Kyoto University, Japan, 24 September - 11 October (2019)
Poster
64 - GW190814 secondary component as a dark matter admixed neutron star
Violetta Sagun, Oleksii Ivanytskyi, Edoardo Giangrandi
at the PHAROS Conference 2022, Rome, Italy, 16 - 19 May (2022)
65 - 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)
66 - Neutron star cooling within the equation of state with induced surface tension
S. Tsiopelas, Violetta Sagun
at the IWARA2020 Video Conference - 9th International Workshop on Astronomy and Relativistic Astrophysics, 6-12 September (2020)
67 - Thermal production of Sexaquarks in heavy ion collisions
D. Blaschke, L. Bravina, K. Bugaev, G. Farrar, B. Grinyuk, O. Ivanytskyi, S. Kabana, Violetta Sagun, A. Taranenko, E. Zabrodin, X. Zhang, D. Zhou
Quark Matter 2019 (2019)
Thesis supervised
Knowledge Transfer
Projects
Management
Outreach
International Collaborations
- University of Potsdam/Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam (Germany)
- University of Oslo, Oslo (Norway)
- Nicolaus Copernicus Astronomical Center, Warsaw (Poland)
- Institute for Theoretical Physics, University of Wroclaw, Wroclaw (Poland)
- Bogolyubov Institute for Theoretical Physics, Kyiv (Ukraine)
