The possibility of one process for making stars and black holes proposed here is -

Gravitational and electromagnetic waves focus on a “seed” of PPD (ProtoPlanetary Disk) material, “concentrically constructing” a planet (building it up layer by layer, incorporating water from the solar nebula into its minerals as its size increases^) from vector-tensor-scalar geometry’s 1÷2 interaction.^^ This produces bodies whose relatively low mass barely enables hydrogen-to-helium fusion before producing high-mass stars. Therefore, low-mass stars outnumber their high-mass cousins. And low-mass stars are outnumbered by brown dwarfs, the failed stars that aren’t quite massive enough to sustain fusion. In turn, brown dwarfs are outnumbered by planets.

^ The work of planetary scientist Lydia Hallis and her colleagues suggests an origin of Earth’s water from the solar nebula, probably delivered by adsorption onto dust grains. (Hallis et al 2015, “Evidence for primordial water in Earth’s deep mantle” - Science 13, Nov 2015, Vol. 350, Issue 6262, pp. 795-797, DOI: 10.1126/science.aac4834.)

^^ Two adjoining sides of a parallelogram represent the vectors of the photon’s spin 1 and the graviton’s spin 2. The resultant diagonal represents the interaction of the sides/vectors (1÷2 = the spin ½ of every matter particle). Tensor calculus changes the coordinates of the sides into the coordinates of a position on a line (a single point on the diagonal). This scalar point is associated with particles of spin 0. If the mass produced (see final paragraph … in parentheses) during the 1÷2 interaction (the energy and momentum of the photons and presently hypothetical gravitons exert a pressure we call mass via the relativistic energy–momentum equation) happens to be 125 GeV/c2, its union with spin 0 produces the Higgs boson. 125 GeV/c2 united with spin 0 means the central scalar point of the Higgs boson is related to the vector of the graviton’s spin 2, and the Higgs field is therefore united with the supposedly unrelated gravitational field (together with the latter’s constant interaction with the electromagnetic field).

The interacting gravity and electromagnetism produce mass e.g. they can form a Higgs boson or the nuclear forces' bosons as well as matter. On a cosmic level - if gravitational and electromagnetic waves focus on a protoplanetary disk surrounding a newborn star, the quantum spin of the particles of matter in the disk (1 / 2) could imprint itself on the waves’ interaction and build up a planet layer by layer from vector-tensor-scalar geometry’s 1÷2 interaction. This method of building planets is preferred to collisions between rocks and dust in the disk because most planetary systems seem to outweigh the protoplanetary disks in which they formed, leaving astronomers to re-evaluate planet-formation theories. (AstroNews: Astronomy magazine, February 2019, p. 17.) If the waves focus on a region of space where there’s no matter, the opposite interaction occurs and the graviton’s spin 2 is divided by the photon’s spin 1 to produce 2÷1. The mass produced has the spin inherent in each of the gravitons composing the body of gravitational waves, and could be an alternative method to supernovas for producing black holes (either stellar-size or rapidly-forming supermassive ones).Virtually all galaxies seem to have big black holes in their centres, and the mass of the black hole correlates remarkably tightly with the mass of the central bulge of the galaxy: this is a result of one process (vector-tensor-scalar geometry) producing either a 1/2 or 2/1 interaction.

What do I mean by “imprint”? To explain using something different – when a laser scanner reads a barcode, the information in the barcode is “imprinted” in the scanner. When gravitational and electromagnetic waves scan a protoplanetary disk, the info in the disk is recorded or imprinted in the waves. When they scan "empty" space-time, the info pertaining to the graviton's spin of 2 (2/1) is imprinted since gravity is space-time according to General Relativity: it says gravity is just another term for the curvature of space-time.

(Material from a star could fall onto a neutron star, heating it up and causing it to emit radiation. Now suppose the paragraph above is true. Then, the energy and momentum of the photons and presently hypothetical gravitons would be the interaction of electromagnetism (the charged particles and strong magnetism) with the neutron star's powerful gravity. The heating could produce gravitational and electromagnetic radiation which would produce the mass and quantum spin of subatomic particles. Instead of only radiation being emitted, jets of matter would be emitted too - the matter would be emitted as beams or jets from the neutron star’s magnetic poles.