160 research outputs found
Cosmic voids and the kinetic analysis. II. Link to Hubble tension
We consider a principal problem, that of the possible dominating role of
self-consistent gravitational interaction in the formation of cosmic
structures: voids and their walls in the local Universe. It is in the context
of the Hubble tension as a possible indication of the difference in the
descriptions of the late (local) and early (global) Universe. The kinetic
Vlasov treatment enables us to consider the evolution of gravitating structures
where the fundamental role has the modified gravitational potential with a
cosmological constant, leading to the prediction of a local flow with a Hubble
parameter that is nonidentical to that of the global Hubble flow. The Poisson
equation for a potential with an additional repulsive term, including an
integral equation formulation, is analyzed, and we predict the appearance of
multiply connected two-dimensional gravitating structures and voids in the
local Universe. The obvious consequence of the developed mechanism is that the
cosmological constant poses a natural scaling for the voids, along with the
physical parameters of their local environment, which can be traced in
observational surveys.Comment: 8 pages, A&A, in pres
Stable Core Symmetries and Confined Textures for a Vortex Line in a Spinor Bose-Einstein Condensate
We show how a singly quantized vortex can exhibit energetically stable defect cores with different symmetries in an atomic spin-1 polar Bose-Einstein condensate, and how a stable topologically nontrivial Skyrmion texture of lower dimensionality can be confined inside the core. The core isotropy and the stability of the confined texture are sensitive to Zeeman level shifts. The observed structures have analogies, respectively, in pressure-dependent symmetries of superfluid liquid He3 vortices and in the models of superconducting cosmic strings
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