### Conveners

#### Friday afternoon session

- Konstantin Postnov (Sternberg Astronomical Institute)

We represent a numerical method for the simulation of 3D differentially rotating astrophysical MHD flows in cylindrical and spherical geometries. This approach belongs to the class of mixed Euler-Lagrange methods. The grid consists of rings which are rotating in a quasi-Lagrangian manner together with the background (differential and solid state) large-scale rotation, significantly reducing...

An optically thin advective accretion disk appears to be indispensable to explain hard-state

of black hole sources. Any transport of matter therein is assumed to be led by (modified) α-viscosity when the magnetic field is weak. We explore how large scale stronger magnetic

field helps in transporting angular momentum, over α-viscosity based transport, depending

on the field geometry....

We use certain compatibility conditions in the formalism of geometrothermodynamics and the non-extensivity property of black holes to argue that the corresponding fundamental equations should be given in terms of quasi-homogeneous functions. As a result, coupling constants in alternative theories of gravity, such as the cosmological constant, the Born-Infeld constant, etc., turn out to be...

Within the precanonical quantization, which we will outline, the dynamics of quantum fields is controlled by the operator of the De Donder-Weyl Hamiltonian (DWH) whose classical version is derived from the Lagrangian. The operator ordering in the DWH operators of GR and its teleparallel equivalent, which is consistent with the diffeomorphism-invariant measure in the scalar product and the...

Calculations of gravitational waves (GWs), both analytical and numerical, assume that they propagate from source to a detector on Earth in a vacuum spacetime. Whilst the average cosmological density of baryonic plus dark matter is small, a detected GW event may be a considerable distance away from its source, up to order 1 Gpc, and the quantity of intervening matter may not be negligible....

In the past decades, several neutron stars (NSs), particularly pulsars, with mass $M>2M_\odot$, have been observed. Hence, there is a generic question of the origin of massive compact objects. Here we explore the existence of massive, magnetized, rotating NSs by solving axisymmetric stationary stellar equilibria in general relativity using the Einstein equation solver for stellar structure XNS...

This paper revives the Descartes-Leibniz debate on the constant quantity of motion. This idea is based on keeping the total energy E=mc2 as a constant where the energy and the mass are independent of the form and speed even when the latter converges to the speed of light. With the increase of the speed, the object transforms the rest energy denoted here as the unexposed energy. The energy...

We aim to study warm inflation via irreversible thermodynamics of open systems with matter creation/decay within Rastall theory of gravity. Interacting scalar field and radiation are assumed to be the components of cosmological fluid in a spatially flat FRW universe model. Considering the early universe as an open system and implementing the thermodynamics on the interacting cosmological fluid...

By using the gravitational decoupling method to create an exact solution to the field equations, this talk discusses the formulation of a charged anisotropic spherically symmetric strange star model. The initial decoupled system is split into Einstein-Maxwell and quasi-Einstein systems using minimal geometric modification. By employing the complexity factor to solve quasi-Einstein field...

General theory and quantum mechanics are fundamentally very different theories with distinct formulations. Nevertheless, both of them claim to predict how Nature works! The everlasting battle for exploring and understanding the Universe and for privileging a consistent perception of reality is therefore awaiting a consolidator rather than a conqueror. This should be capable of either unifying...