相关论文: QCD Axion Star Collapse with the Chiral Potential

Taking a comprehensive view, including a full range of boundary conditions, we reexamine QCD axion star solutions based on the relativistic Klein-Gordon equation (using the Ruffini-Bonazzola approach) and its non-relativistic limit, the…

The QCD axion offers a natural resolution to the strong CP problem and provides a compelling dark matter candidate. If the QCD axion constitutes all the dark matter, the simplest models pick out a narrow range of masses around $100\,\mu{\rm…

A number of long-standing puzzles, such as the origin of ultrahigh-energy cosmic rays, could perhaps be solved if we found a mechanism for effectively transferring energy from black holes to particles and, correspondingly, accelerating the…

A critique of the singularity theorems of Penrose, Hawking, and Geroch is given. It is pointed out that a gravitationally collapsing black hole acts as an ultrahigh energy particle accelerator that can accelerate particles to energies…

We investigate the collapse of a circularly symmetric star with outgoing radiation in ($2+1$)-dimensional anti-de Sitter spacetime. The exterior spacetime of the collapsing star is assumed to be described by the non-static generalization of…

According to the traditional scenario for core-collapse supernovae, the core of the collapsing star forms a neutron star and its gravitational energy release sends out a shockwave into the stellar envelope. However, in a significant number…

Mechanisms that dynamically relax the vacuum energy offer a concrete way to approach the cosmological constant problem, but because relaxation is not confined to the vacuum energy alone it can have consequences for the rest of low-energy…

We present novel findings concerning the parameter space of axion stars, extended object forming in dense dark matter environments through gravitational condensation. We emphasize their formation within the dense minihalos that potentially…

We reconsider entropy arguments which have been previously argued to support the idea that the dark matter constituents are primordial black holes with many solar masses. It has recently been shown that QCD axions which solve the strong CP…

If the dark matter particles are axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound systems of axions. In the previously known solutions for axion stars, gravity and the attractive force…

We study the spherical collapse model in dark energy cosmologies, in which dark energy is modelled as a minimally coupled scalar field. We first follow the standard assumption that dark energy does not cluster on the scales of interest.…

Along with compacting baryon (neutron) spacing in a neutron star (NS), two very important factors come into play side by side: the lack of the NS gravitational self-stabilization against shutting to black hole (BH) and the phase transition…

The present surge for the astrophysical relevance of boson stars stems from the speculative possibility that these compact objects could provide a considerable fraction of the non-baryonic part of dark matter within the halo of galaxies.…

Do observations of black hole candidates rule out alternative theories of gravity without horizon formation? This depends on the existence, viability and reasonableness of alternative theories of gravity without black holes. Here a theory…

The QCD axion acquires the potential through the non-perturbative effect of the QCD matters around the QCD phase transition. During this period, the direct interaction between the axion and the QCD matters sets in. Focusing on the impact of…

Recently, two of the present authors showed that even when the axion momentum is much smaller than its mass, the axion can still behave like radiation if its energy density greatly exceeds the maximum potential energy set by the cosine-type…

In the QCD axion scenario, a network of domain walls bounded by cosmic strings fragments into pieces. As these fragments collapse, some of them will form black holes. With standard QCD axion parameters, the black holes will have lunar…

Dark matter in the form of axions is expected to form miniclusters, and their dense regions can harbor compact axion stars. Such axion stars could be discovered by microlensing events. In particular, some candidate events reported by Subaru…

A new argument is presented confirming the point of view that a Schwarzschild black hole formed during a collapse process does not radiate.

The possibility of the existence of quark stars has been discussed by several authors since 1970. Recently, it has been pointed out that two putative neutron stars, RXJ 1856.5 - 3754 in Corona Australis and 3C58 in Cassiopeia are too small…