Conveners
Black hole formation, evolution and the black hole mass gap: Tuesday block 1
- Grant Mathews (University of Notre)
Black hole formation, evolution and the black hole mass gap: Tuesday block 2
- Grant Mathews (University of Notre)
Description
There is much current interest in the formation and evolution of black holes in relation to the black hole mass gap. The pair instability supernova in massive stars is believed to prohibit the formation of black holes in the range of 50-120 solar masses. Nevertheless, possible detections suggest the existence of black holes with masses well inside the "mass gap". Many ideas have emerged to explain the existence of black holes in the mass gap. This session will include talks summarizing various approaches to this dilemma.
In recent work [1,2] we have shown that within the natural warm inflationary paradigm (WNI) observational constraints on the primordial power spectrum from the cosmic microwave background (CMB) can be satisfied without going beyond the Planck scale of the effective field theory. Moreover, WNI can inevitably provide perfect conditions for the production of primordial black holes (PBHs) in the...
In this talk, I will discuss the probability distribution of the spins of primordial black holes (PBHs) formed in a matter-dominated universe. For this evaluation, I focus on cosmological perturbations that follow a Gaussian distribution and examine their linear-order effects on the tidal torque they generate. By the time the fluid gravitationally collapses to form a PBH, nonlinear effects...
We find an exact time-dependent instanton solution on a vacuum Kerr-like warped spacetime in conformal dilaton gravity. The antipodal boundary condition on the hypersurface of a Klein bottle $\sim \mathbb{C}^1\times\mathbb{C}^1$ is used to describe the Hawking particles. We used the Hopf fibration to get $S^2$ as the black hole horizon, where the centrix is not in a torus but in the Klein...
Most observed binary black hole (BBH) mergers belong to the stellar-mass BBH population produced by the collapse of isolated stars. A pair-instability supernova (PISN) mechanism prevents the formation of black holes from the stellar collapse with mass greater than 50 and less than 120 solar masses. Any BBH merger with a component black hole in the PISN mass gap is likely to originate from an...
Observationally, it is well established that the masses of central black holes are tightly correlated with galaxy properties, most notably the bulge’s velocity dispersion. Cosmological hydrodynamical simulations can capture most of these correlations, but it is yet not understood why this occurs. To gain greater insight into central black hole growth we use machine learning algorithms to study...
In this talk I will show that the theoretical model of physical black holes predict that gravitational wave echos acoompanies with all the black hole merger events in real world. The first part of my talk will be introducing the concept of physical black holes, highlighting that all the black holes in observed in astronomy should be discribed by dynamical, horizonless and singular free metric....
Existence of naked singularities is a topical and fundamental issue of physics. The formation mechanism of such objects, particularly those with near-solar-mass, is not yet clear. Since, recent gravitational wave events have suggested the existence of near-solar-mass collapsed objects which cannot be formed via stellar evolution, here we investigate a likely formation channel, and especially...
Spherical collapse in general relativity has been studied with different methods, especially by using a priori given equations of state that describe the collapsing matter as a perfect fluid. We propose an alternative perspective, in which the initial density of the perfect fluid is given as a polynomial function of the radial coordinate that is regular everywhere inside the fluid. We then...
Electric and magnetic fields of a charged ring located in the vicinity of Kerr black hole are computed with multipole decomposition. Lines of force of electric and of magnetic fields in the ZAMO frame are presented and analyzed for different positions of the ring and selected values of the Kerr parameter. Special attention is paid to the case when position of the ring approaches the event...
