The instability of a black hole with $f(R)$ global monopole under extended uncertainty principle

Monopole core instability and Alice rings in spinor Bose-Einstein condensates

We show how the length scale hierarchy, resulting from different interaction strengths in an optically-trapped spin-1 sodium-23 Bose-Einstein condensate, can lead to intriguing core deformations in singular topological defects. In particular, a point defect can be unstable with respect to the formation of a stable half-quantum vortex ring (an Alice ring), providing a realistic scheme to use dissipation as a sophisticated state engineering tool. We compute the threshold for stability of the point monopole, which is beyond the current experimental regime.

磁性黑洞的超辐射不稳定性

Superradiant Instability of Magnetic Black Holes

本文研究带磁荷旋转黑洞的超辐射不稳定性，发现其不稳定性时标远短于中性黑洞，确定沿旋转轴延伸的南北单极子模式为最不稳定模式，同时证实带电无质量场无此类不稳定性。

Corrections to the fine structure constant in higher dimensional global monopole spacetime

In this paper we use the Generalized Uncertainty Principle in order to obtain the corrections to the fine structure constant in (D+1)-dimensional global monopole spacetime. The result is particularized to D-dimensional spacetime. We also discuss the particular case D=3 corresponding to the (3+1)-dimensional global monopole spacetime.

Thermodynamic phase transition of a Schwarzschild black hole with global monopole under GUP

In this paper, considering the influence of the principle of generalized uncertainty (GUP), the phase transition of a Schwarzschild black hole with global monopole is discussed. First, we use the generalized Dirac equation to obtain corrected Hawking temperature, local temperature, black hole residue, black hole entropy, thermal capacity, and other thermodynamic quantities. Then, we use images to analyze the effects of generalized uncertainty parameters on phase transitions and the effects of magnetic monopole parameters on phase transitions. Finally, we study the thermodynamic stability and p…

平面上的磁单极磁流体力学：磁声波与发电机不稳定性

Monopole magnetohydrodynamics on a plane: Magnetosonic waves and dynamo instability

本文研究二维凝聚态系统中磁单极存在下的电磁学，发现电阻导致电磁场衰减，但存在磁流体力学区域，其磁声波各向同性且受奇粘滞系数影响，发电机作用需流动可压缩性。

Magnetic condensation, Abelian dominance, and instability of Savvidy vacuum in Yang-Mills theory

We propose a novel type of color magnetic condensation originating from magnetic monopoles so that it provides the mass of off-diagonal gluons in the Yang-Mills theory. This dynamical mass generation enables us to explain the infrared Abelian dominance and monopole dominance by way of a non-Abelian Stokes theorem, which supports the dual superconductivity picture of quark confinement. Moreover, we show that the instability of Savvidy vacuum disappears by sufficiently large color magnetic condensation.

Scattering Cross Section and Stability of Global Monopoles

We study the scattering of scalar waves propagating on the global monopole background. Since the scalar wave operator in this topological defect is not essentially self-adjoint, its solutions are not uniquely determined until a boundary condition at the origin is specified. As we show, this boundary condition manifests itself in the differential cross section and can be inferred by measuring the amplitude of the backscattered wave. We further demonstrate that whether or not the spacetime is stable under scalar perturbations also relies on the chosen boundary condition. In particular, we identi…

Troubles with Global Monopoles in Quantum Gravity

A theory with a global $O(3)$ symmetry broken at a scale $η$ admits topological configurations: global monopoles realized by Goldstone fields winding around the core of false vacuum. One may expect them to behave as heavy, big composite objects, difficult to make and therefore mostly harmless. However, after gravity is turned on, as long as Equivalence Principle holds, one finds that global monopoles have a negative mass, $M \sim - η/\sqrtλ$, where $λ$ is the field theory coupling. This could catalyze an instability in the space of a global monopole, by the production of additional global mono…

A Classical Instability of Reissner-Nordstrom Solutions and the Fate of Magnetically Charged Black Holes

Working in the context of spontaneously broken gauge theories, we show that the magnetically charged Reissner-Nordstrom solution develops a classical instability if the horizon is sufficiently small. This instability has significant implications for the evolution of a magnetically charged black hole. In particular, it leads to the possibility that such a hole could evaporate completely, leaving in its place a nonsingular magnetic monopole.

Magnetic condensation, Abelian dominance and instability of Savvidy vacuum

We show that a certain type of color magnetic condensation originating from magnetic monopole configurations is sufficient to provide the mass for off-diagonal gluons in the SU(2) Yang-Mills theory under the Cho--Faddeev--Niemi decomposition. We point out that the generated gluon mass can cure the instability of the Savvidy vacuum. In fact, such a novel type of magnetic condensation is shown to occur by calculating the effective potential. This enables us to explain the infrared Abelian dominance and monopole dominance by way of a non-Abelian Stokes theorem, which suggests the dual superconduc…

U(1)狄拉克自旋液体的自旋-派尔斯不稳定性

Spin-Peierls instability of the U(1) Dirac spin liquid

本研究针对三角晶格海森堡反铁磁体中的U(1)狄拉克自旋液体，揭示了晶格畸变与磁单极子的耦合会引发自旋-派尔斯不稳定性，同时指出声子能隙可维持自旋液体稳定，结果对笼目晶格等体系也具有适用性。

Black holes with massive graviton hair

No-hair theorems exclude the existence of nontrivial scalar and massive vector hair outside four-dimensional, static, asymptotically flat black-hole spacetimes. We show, by explicitly building nonlinear solutions, that black holes can support massive graviton hair in theories of massive gravity. These hairy solutions are, most likely, the generic end state of the recently discovered monopole instability of Schwarzschild black holes in massive graviton theories.

关于电磁单极子的内部机械性质及其对稳定性的影响

On internal mechanical properties of Electroweak Magnetic Monopoles and their effects on stability

研究电磁单极子的内部机械性质及其稳定性，发现其内部力导致不稳定性，但Born-Infeld扩展模型可能受旋转影响而不一定不稳定。