We want to explain non-observation of electromagnetic counterpart of currently confirmed 10 gravitational wave signals from the black hole mergers assuming their existence in the hidden mirror universe. Mirror matter, which interacts with our world only through gravity, is a candidate of dark matter and its density can exceed ordinary matter density five times. Since mirror world is considered to be colder, star formation there started earlier and mirror black holes had more time to pick up the mass and to create more binary systems within the LIGO reachable zone. Totally we estimate a factor 10 amplification of black holes merging rate in mirror world with respect to our world, which is consistent with the LIGO observations.

In this paper we consider the properties of the 10 confirmed by the LIGO (Laser Interferometer Gravitational-Wave Observatory) Collaboration gravitational wave signals from the black hole mergers. We want to explain non-observation of electromagnetic counterpart and higher then expected merging rates of these events, assuming the existence of their sources in the hidden mirror universe. Mirror matter, which interacts with our world only through gravity, is a candidate of dark matter and its density can exceed ordinary matter density five times. Since mirror world is considered to be colder, star formation there started earlier and mirror black holes had more time to pick up the mass and to create more binary systems within the LIGO reachable zone. In total, we estimate factor of 15 amplification of black holes merging rate in mirror world with respect to our world, which is consistent with the LIGO observations.

We consider the possibility that LIGO events GW190521, GW190425, and GW190814 may have emerged from the mirror world binaries. Theories of star evolution predict so-called upper and lower mass gaps and masses of these merger components lie in that gaps. In order to explain these challenging events very specific assumptions are required and we argue that such scenarios are order of magnitude more probable in mirror world, where star formation begins earlier and matter density can exceed five times the ordinary matter density.

The GELATICA project (GEorgian Large-area Angle and TIme Coincidence Array) consists of several cosmic ray detector arrays located in two cities in Georgia. Designed to detect Extensive Air Showers (EAS) with high-precision timing, these observatories aim to reconstruct the arrival directions of cosmic ray showers. GELATICA is the part of the international CREDO collaboration (Cosmic Ray Extremely Distributed Observatory), with a primary goal of searching for Cosmic Ray Ensembles (CRE)—correlated cosmic ray events potentially originating from a common astrophysical or exotic source. This paper presents an overview of GELATICA's instrumentation and methodology, along with an analysis of multi-year data. We evaluate detector performance, characterize the distribution of recorded signals, and assess the potential for detecting CREs via coincident signals across spatially separated arrays. We report the detection of two pairs of events coinciding in time with 0.5 millisecond accuracy. However, the arrival directions of these coincident events do not suggest a common origin. Nevertheless, further data collection and an increased number of observatories could enhance the likelihood of identifying true CRE candidates.

We want to explain non-observation of electromagnetic counterpart of currently confirmed ten gravitational wave signals from the black hole mergers assuming their existence in the hidden mirror universe. Mirror matter, which interacts with our world only through gravity, is a candidate of dark matter and its density can exceed ordinary matter density five times. Since mirror world is considered to be colder, star formation there started earlier and mirror black holes had more time to pick up the mass and to create more binary systems within the LIGO reachable zone. Totally we estimate a factor 10 amplification of black holes merging rate in mirror world with respect to our world, which is consistent with the LIGO observations.