https://uniba.sk/ Najnovšie novinky sk https://uniba.sk/fileadmin/tt_news_article.gif https://uniba.sk/ Najnovšie novinky TYPO3 - get.content.right http://blogs.law.harvard.edu/tech/rss Thu, 31 Dec 2026 00:00:00 +0100 https://uniba.sk/ Thursday 15.6.2023 at 10:00, Lecture room F1/364 prof. Gennady Kozlov (JINR Dubna / CERN Geneva):
Boson stars, primary photons and phase transition
Abstract:
We analyze the possibility that the dark matter candidate is from the approximate scale symmetry theory of the hidden scalar sector. The study includes the warm dark matter scenario and the Bose-Einstein condensation which may lead to massive dark scalar boson stars giving rise to direct detection through observation of the primary (direct) photons. The dynamical system of the scalar particles, the dilatons, at finite temperature and chemical potential is considered. The fluctuation of the particle density increases sharply within the increasing of the temperature. When the phase transition approaches, the fluctuation of the particle density has the non-monotonous rising when the ground state of the relative chemical potential tends to one with the infinite number of the particles. Our results suggest that the phase transition in the boson star may be identified through the fluctuation in yield of primary photons induced directly by the conformal anomaly. The fluctuation rate of the primary photons grows up intensively in the infra-red to become very large at the phase transition. ]]> [FMFI] Prednášky a semináre [FMFI] Kalendár Jaroslav.Stanicek@fmph.uniba.sk Sun, 11 Jun 2023 21:52:00 +0200 https://uniba.sk/ FMPH CU is organizing during 12-15 June 2023 the CRESST Symposium to discuss present status and... 2, and in this mass range it is a world leader in DM experiments. The CRESST uses highly sensitive cryogenic particle detectors to detect the small amount of energy deposited in a detection crystal by a single-particle interaction.  The detectors are cooled down to 15 mK, which enables to register even small temperature increases (of a millionth of a degree) using very sensitive devices to detect temperature changes. The CRESST collaboration developed very sensitive coincidence detection systems, combining temperature signals with scintillation signals, as a few percent of the deposited energy is emitted in the form of scintillation light. Various crystals were used in the experiments, including, e.g., CaWO₄, LiAlO2, Si, diamond, etc. The CRESST experiment obtained the world’s lowest limit for the scattering of light-dark matter particles on protons (5･10^-35 cm² at mass of 1 GeV/c²). The CRESST experiment is located in the LNGS (Laboratori Nazionali del Gran Sasso),  a deep underground laboratory operating under the Gran Sasso mountain in Italy. The LNGS is the world's largest underground laboratory (shielded by 1400 m of rocks) which is hosting several experiments. The CRESST collaboration combines about 60 physicists from eight institutes representing Germany, Italy, Austria, Slovakia, and the UK. Our contribution (R. Breier, M. Ješkovský, J. Kaizer, I. Kontuľ, P. Povinec, J. Zeman) to the experiment has been in the development of methods for radiopurity investigations of construction parts of the detectors (as the main contribution to their background has been from natural radionuclides), as well as in Monte Carlo simulations of the detector background due to interactions of cosmic-ray particles and radiation emitted from decays of natural radionuclides). As the known matter represents only 5% of all matter (25% is estimated to be DM and 70% is dark energy), this fundamental research represents greatest challenge for a better understanding of physics and in general the Universe.]]> [FMFI] Konferencie [FMFI] Titulka - úzke novinky Pavel.Povinec@fmph.uniba.sk Sat, 10 Jun 2023 22:45:00 +0200 https://uniba.sk/ [Druzba] - Titulka - slider Wed, 26 Jul 2023 15:08:00 +0200 https://uniba.sk/ [Druzba] - Titulka - slider Wed, 26 Jul 2023 15:08:00 +0200 https://uniba.sk/ [Druzba] - Titulka - slider Wed, 26 Jul 2023 15:09:00 +0200 https://uniba.sk/ [Translate to English:] Družba - obr. D5 [Druzba] - Titulka - slider Wed, 26 Jul 2023 15:12:00 +0200 https://uniba.sk/ [Druzba] - Titulka - slider Wed, 26 Jul 2023 15:12:00 +0200 https://uniba.sk/ [Mlyny] Titulka - slider Wed, 26 Jul 2023 15:14:00 +0200 https://uniba.sk/ [Mlyny] Titulka - slider Wed, 26 Jul 2023 15:15:00 +0200 https://uniba.sk/ [Mlyny] Titulka - slider Wed, 26 Jul 2023 15:16:00 +0200