Recent investigations by Noordhuis et al. [1, 2] and others have demonstrated the occurrence of strong local inhomogeneous axion regions in the polar cap regions of neutron stars. These regions are characterized by static magnetic fields B_0 ∼ 10^8T (=10^12G) directed normally outwards from the polar surface (magnetic dipole), together with static electric fields E_0 ∼ 10^-6cB_0 in the same direction (electric dipole). An enormous increase of axion production, up to order 10^50, is predicted in the polar regions. These features are important for phenomena such as polarization plane rotation under both weak and strong axion field populations. We survey the peculiar antenna property of conductive materials, which shows the need for having very strong magnetic fields to make the detection possible. We present the general form of electromagnetic waves in the axion environment, in both the standard form and in a physically instructive hybrid one, showing the nonreciprocity of axion fluid, and calculate the polarization rotation. The rotation is well defined in the case of weak, but still stronger than average value of axion fields in Universe. For very strong fields such a perturbative theory breaks down, however. A noteworthy general property of the rotation of polarization plane is that it can only occur when the axion cloud is varying in space or time. We limit ourselves only variation in space. Finally, as application we discuss the physical picture of local 'gap' regions proposed by Noordhuis et al. in the polar regions of a neutron star. The reason for occurrence of these gaps is plasma effects. To evaluate the time scales involved, we calculate the filling time for surrounding axions flowing into an initial gap. It turns out that the typical filling time is a moderate number of nanoseconds, within the accuracy of atomic clocks precision to be detectable.
We obtain asymptotic estimates of the interaction forces between kink and antikink in a family of field-theoretic models with two vacua in (1+1)-dimensional space-time. In our study we consider a new class of soliton solutions previously found in our paper [Chaos, Solitons and Fractals 165 (2022) 112805]. We focus on the case of kinks having one exponential and one power-law asymptotics. We show that if the kink and antikink are faced each other with long-range tails, the force of attraction between them at large separations demonstrates a power-law decay with the distance. We also performed numerical simulations to measure the interaction force and obtained good agreement between the experimental values and theoretical estimates.
Abstract. The problems of using terrestrial laser scanning imaging for the tasks of ensuring the safety of nuclear energy facilities are considered. The greatest attention is paid to the issues of decommissioning and control of facilities for the disposal of radioactive waste (near-surface burial sites and conservation sites for special radioactive waste) at the stages after closure and long-term exposure. It is shown that digital information models are the best environment for the concentration of all data types necessary for decommissioning and justification of safety. The issues of interfacing data from digital models of objects with data from radiation surveys and other surveys are considered. The use of terrestrial laser scanning imaging in conjunction with radiation studies and other surveys with the preservation of results in the IFC format is proposed.
We analyze the parity violation issue in the Poincaré gauge theory of gravity for the two classes of models which are built as natural extensions of the Einstein–Cartan theory. The conservation laws of the matter currents are revisited and we clarify the derivation of the effective Einstein field equation and the structure of the effective energy–momentum current for arbitrary matter sources.
