scholarly journals Primordial monopolium as dark matter

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Vicente Vento
Keyword(s):  
Dark Matter ◽  
Magnetic Fields ◽  
Magnetic Moment ◽  
Free Space ◽  
Energy State ◽  
Bound State ◽  
Time Dependent ◽  
Astrophysical Scenario ◽  
Kaluza Klein

AbstractThe existence of monopoles is a characteristic signature of Kaluza–Klein multidimensional theories. The topology of these solutions is extremely interesting. The existence of a dipole solution, which we have associated to a monopole–anti-monopole bound state, is the leitmotiv of this investigation. The dipole in its lowest energy state, which we here call also monopolium, is electromagnetically inert in free space interacting only gravitationally. Monopolium when interacting with time dependent magnetic fields acquires a time dependent induced magnetic moment and radiates. We have analyzed the most favorable astrophysical scenario for radiative monopolium and found that the amount of radiation is so small that is not detectable by conventional equipments. These findings suggest that Kaluza–Klein monopolium, if existent, would be a candidate for a primordial dark matter constituent.

scholarly journals A Quantum Charged Particle under Sudden Jumps of the Magnetic Field and Shape of Non-Circular Solenoids

2019 ◽  
Vol 1 (2) ◽  
pp. 193-207 ◽  
Author(s):  
Viktor V. Dodonov ◽  
Matheus B. Horovits
Keyword(s):  
Magnetic Field ◽  
Charged Particle ◽  
Magnetic Fields ◽  
Electric Fields ◽  
Cross Sections ◽  
Magnetic Moment ◽  
Landau Gauge ◽  
Time Dependent ◽  
The Mean ◽  
The Magnetic Field

We consider a quantum charged particle moving in the x y plane under the action of a time-dependent magnetic field described by means of the linear vector potential of the form A = B ( t ) − y ( 1 + β ) , x ( 1 − β ) / 2 . Such potentials with β ≠ 0 exist inside infinite solenoids with non-circular cross sections. The systems with different values of β are not equivalent for nonstationary magnetic fields or time-dependent parameters β ( t ) , due to different structures of induced electric fields. Using the approximation of the stepwise variations of parameters, we obtain explicit formulas describing the change of the mean energy and magnetic moment. The generation of squeezing with respect to the relative and guiding center coordinates is also studied. The change of magnetic moment can be twice bigger for the Landau gauge than for the circular gauge, and this change can happen without any change of the angular momentum. A strong amplification of the magnetic moment can happen even for rapidly decreasing magnetic fields.

Movement of magnetic bacteria in time-varying magnetic fields

1994 ◽  
Vol 273 ◽  
pp. 189-211 ◽  
Author(s):  
Bernhard Steinberger ◽  
Nikolai Petersen ◽  
Harald Petermann ◽  
Dieter G. Weiss
Keyword(s):  
Magnetic Fields ◽  
Motion Analysis ◽  
Magnetic Moment ◽  
Model Experiment ◽  
Magnetic Particles ◽  
Time Dependent ◽  
Time Varying ◽  
Drag Coefficients ◽  
Surrounding Liquid

The magnetic moment of individual living magnetic bacteria was determined by motion analysis in a time-dependent magnetic field. For this purpose we had to estimate the drag exerted on the moving bacterium by the surrounding liquid. First, the bacterium was approximated by an ellipsoid. In order to determine drag coefficients for more complicated (and realistic) forms, a model experiment was built. In this experiment enlarged models of bacteria were rotated in a viscous liquid and the torque acting upon them was measured. Computing algorithms were developed in order to calculate drag coefficients of magnetic bacteria and to simulate their motion in magnetic fields. The experimental and numerical determination of the drag coefficients agree within their error bounds. Besides the determination by motion analysis, the bacterial magnetic moment was also calculated from the number and size of magnetic particles contained in the bacterium as seen in an electron microscope. The results of both calculations agree well.

scholarly journals Hamiltonian Approach to Magnetic Fields with Toroidal Surfaces

1985 ◽  
Vol 40 (10) ◽  
pp. 959-967
Author(s):  
A. Salat
Keyword(s):  
Magnetic Field ◽  
Hamiltonian System ◽  
Magnetic Fields ◽  
Constant Pressure ◽  
Time Dependent ◽  
Hamiltonian Approach ◽  
One Dimensional ◽  
Mhd Equilibrium ◽  
Magnetic Surfaces ◽  
Rotational Transform

The equivalence of magnetic field line equations to a one-dimensional time-dependent Hamiltonian system is used to construct magnetic fields with arbitrary toroidal magnetic surfaces I = const. For this purpose Hamiltonians H which together with their invariants satisfy periodicity constraints have to be known. The choice of H fixes the rotational transform η(I). Arbitrary axisymmetric fields, and nonaxisymmetric fields with constant η(I) are considered in detail.Configurations with coinciding magnetic and current density surfaces are obtained. The approach used is not well suited, however, to satisfying the additional MHD equilibrium condition of constant pressure on magnetic surfaces.

scholarly journals Detecting dark photons from atomic rearrangement in the galaxy

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
James Eiger ◽  
Michael Geller
Keyword(s):  
Dark Matter ◽  
Ground State ◽  
Bound State ◽  
Current Data ◽  
Dark Sector ◽  
Atomic Process ◽  
The Galaxy ◽  
Atomic States ◽  
Atomic Rearrangement

Abstract We study a new dark sector signature for an atomic process of “rearrangement” in the galaxy. In this process, a hydrogen-like atomic dark matter state together with its anti-particle can rearrange to form a highly-excited bound state. This bound state will then de-excite into the ground state emitting a large number of dark photons that can be measured in experiments on Earth through their kinetic mixing with the photon. We find that for DM masses in the GeV range, the dark photons have enough energy to pass the thresholds of neutrino observatories such as Borexino and Super-Kamiokande that can probe for our scenario even when our atomic states constitute a small fraction of the total DM abundance. We study the corresponding bounds on the parameters of our model from current data as well as the prospects for future detectors.

scholarly journals Dark matter, muon anomalous magnetic moment, and the XENON1T excess

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Debajyoti Choudhury ◽  
Suvam Maharana ◽  
Vandana Sahdev ◽  
Divya Sachdeva
Keyword(s):  
Dark Matter ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Muon Anomalous Magnetic Moment

GROUND STATE CHARGE OF FERMION SOLITON SYSTEM IN 1+1 AND 3+1 DIMENSIONS

1993 ◽  
Vol 08 (04) ◽  
pp. 705-721
Author(s):  
M. RAVENDRANADHAN ◽  
M. SABIR
Keyword(s):  
Ground State ◽  
Energy State ◽  
Flow Analysis ◽  
Background Field ◽  
Bound State ◽  
Fermion Mass ◽  
Spectral Flow ◽  
Bound State Spectrum ◽  
Spectral Asymmetry ◽  
State Charge

Ground state charge of some fermion soliton system without C-invariance is calculated in 1+1 and 3+1 dimensions by a combination of adiabatic method and spectral flow analysis. Induced charge is calculated by evolving adiabatically the fields from a vacuum having a background field which has a zero energy state and spectral symmetry. The spectral flow is calculated by an analysis of the bound state spectrum. In 1+1 dimension our calculations are in agreement with the results already found in the literature. In 3+1 dimension we study the interaction of fermions with monopoles and dyons. In the case of monopoles, even though there is spectral asymmetry, ground state charge is found to be ±1/2. It is shown that ground state charge gets contribution only from the lowest angular momentum states and is discontinuous at the fermion mass.

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