scholarly journals Electroweak axion string and superconductivity

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Yoshihiko Abe ◽  
Yu Hamada ◽  
Koichi Yoshioka
Keyword(s):  
Electric Current ◽  
Early Universe ◽  
Parameter Space ◽  
Cosmic String ◽  
Topological Charge ◽  
Attractive Force ◽  
Electroweak Scale ◽  
Large Current

Abstract We study the axion strings with the electroweak gauge flux in the DFSZ axion model and show that these strings, called the electroweak axion strings, can exhibit superconductivity without fermionic zeromodes. We construct three types of electroweak axion string solutions. Among them, the string with W-flux can be lightest in some parameter space, which leads to a stable superconducting cosmic string. We also show that a large electric current can flow along the string due to the Peccei-Quinn scale much higher than the electroweak scale. This large current induces a net attractive force between the axion strings with the same topological charge, which opens a novel possibility that the axion strings form Y-junctions in the early universe.

scholarly journals Axion strings are superconducting

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Hajime Fukuda ◽  
Aneesh V. Manohar ◽  
Hitoshi Murayama ◽  
Ofri Telem
Keyword(s):  
Magnetic Field ◽  
Charge Density ◽  
Electric Current ◽  
Early Universe ◽  
Drag Force ◽  
Parameter Space ◽  
Electromagnetic Force ◽  
Large Current ◽  
Primordial Magnetic Field ◽  
Relic Abundance

Abstract We explore the cosmological consequences of the superconductivity of QCD axion strings. Axion strings can support a sizeable chiral electric current and charge density, which alters their early universe dynamics. We examine the possibility that shrinking axion string loops can become effectively stable remnants called vortons, supported by the repulsive electromagnetic force of the string current. We find that vortons in our scenario are generically unstable, and so do not pose a cosmological difficulty. Furthermore, if a primordial magnetic field (PMF) exists in the early universe, a large current is induced on axion strings, creating a significant drag force from interactions with the surrounding plasma. As a result, the strings are slowed down, which leads to an orders of magnitude enhancement in the number of strings per Hubble volume. Finally, we study potential implications for the QCD axion relic abundance. The QCD axion window is shifted by orders of magnitude in some parts of our parameter space.

scholarly journals Angle deficit and nonlocal gravitoelectromagnetism around a slowly spinning cosmic string

2020 ◽  
Vol 29 (14) ◽  
pp. 2043027
Author(s):  
Jens Boos
Keyword(s):  
Gravitational Field ◽  
Symmetry Breaking ◽  
Early Universe ◽  
Physical Interpretation ◽  
Cosmic String ◽  
Cosmic Strings ◽  
Radial Distance ◽  
Gravitomagnetic Field ◽  
Simply Connected

Cosmic strings, as remnants of the symmetry breaking phase in the Early universe, may be susceptible to nonlocal physics. Here, we show that the presence of a Poincaré-invariant nonlocality—parametrized by a factor [Formula: see text]—regularizes the gravitational field and thereby changes the properties of spacetime: it is now simply connected and the angle deficit around the cosmic string becomes a function of the radial distance. Similar changes occur for the nonlocal gravitomagnetic field of a rotating cosmic string, and we translate these mathematical facts into the language of nonlocal gravitoelectromagnetism and thereby provide a physical interpretation. We hope that these insights might provide a helpful perspective in the search for traces of nonlocal physics in our universe.

THE ORDER PARAMETER FIELD FOR COSMIC STRING, INFLATION AND DARK ENERGY

2003 ◽  
Vol 18 (36) ◽  
pp. 2587-2597 ◽  
Author(s):  
PENG-MING ZHANG ◽  
YI-SHI DUAN ◽  
LI-MING CAO
Keyword(s):  
Dark Energy ◽  
Scalar Field ◽  
Early Universe ◽  
Cosmic String ◽  
Order Parameter ◽  
Cosmic Strings ◽  
Complex Scalar ◽  
Parameter Field ◽  
Complex Scalar Field

We present a whole frame for the cosmic strings, inflation and dark energy with the complex scalar field which can be regarded as the order parameter of our universe. One can find that the comic strings emerge in the zeros of the complex scalar field in the early universe. And with the evolution of complex scalar field, inflation and dark energy can be understood in this frame.

scholarly journals Material Test Comparison of Pure Aluminum (Al) and Pure Aluminum-Coated (Al) with Silver (Ag) Substrat Using Electroplating Method

2021 ◽  
Vol 1 (2) ◽  
pp. 40-46
Author(s):  
Aming Sungkowo ◽  
Trikolas Trikolas ◽  
Rosyid Ridlo Al Hakim ◽  
Slamet Riyadi ◽  
Yanuar Zulardiansyah Arief ◽  
...  
Keyword(s):  
Electric Current ◽  
Pure Aluminum ◽  
Material Testing ◽  
Coating Process ◽  
Material Test ◽  
Large Current ◽  
Research Goal ◽  
Electroplating Process ◽  
Aluminum Material

Electroplating uses aluminum material, where it’s easy to obtain, lighter, and cheaper than other metals. The research goal was to determine the ability of the electric current to power aluminum (Al) coated with silver (Ag) by the electroplating method, to determine the effect of the magnitude of the electric current and the length of time the coating process took on the weight of Al coated with Ag and to determine the strength of the metal Al after tested using Brinnell test. The method used is to compare pure Al and pure Al coated with Ag by electroplating at different currents to determine the effect of the electroplating process. A Brinnell test was carried out to determine the hardness of the Al material after electroplating. The results are the amount of current that flows during the electroplating is directly proportional to the thickness of the electroplating layer attached to the Al surface. If the electroplating process uses a large current, the attached layer will look rough and not smooth, which also affects the material testing by using the Brinnell method. The Brinnell test proves that the hardness value of the Al material is directly proportional to the thickness of the layer.

MONOPOLE ACCRETION BY COSMIC STRINGS

1990 ◽  
Vol 05 (17) ◽  
pp. 1313-1320
Author(s):  
A.M. MATHESON ◽  
D.M. UPTON
Keyword(s):  
Black Holes ◽  
Neutron Star ◽  
Early Universe ◽  
Cosmic String ◽  
Cosmic Strings ◽  
Magnetic Monopoles ◽  
Accretion Process

We study the accretion of super-heavy magnetic monopoles around cosmic string loops in the very early universe. For sufficiently massive monopoles, a possible result of this accretion process is the formation of monopole-black holes, leading ultimately to a monopole-to-photon ratio comparable to the limits required by neutron star observations.

scholarly journals COSMIC STRING SPACETIME IN DILATON GRAVITY AND FLAT ROTATION CURVES

2004 ◽  
Vol 19 (39) ◽  
pp. 2929-2940 ◽  
Author(s):  
TAE HOON LEE
Keyword(s):  
Phase Transition ◽  
Gauge Symmetry ◽  
Early Universe ◽  
Cosmic String ◽  
Topological Defect ◽  
Galactic Rotation ◽  
Dilaton Gravity ◽  
Rotation Curves ◽  
Flat Rotation Curves ◽  
Vacuum Solutions

In dilaton gravity theories, we consider a string-like topological defect formed during U (1) gauge symmetry-breaking phase transition in the early Universe, and far from the cosmic string we have vacuum solutions of the generalized Einstein equation. We discuss how they can be related to the flatness of galactic rotation curves.

On the self-similar exact MHD jet solution

2014 ◽  
Vol 746 ◽  
pp. 5-30 ◽  
Author(s):  
R. I. Mullyadzhanov ◽  
N. I. Yavorsky
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Reverse Flow ◽  
Pitchfork Bifurcation ◽  
Poloidal Magnetic Field ◽  
Boundary Layer Equations ◽  
Large Current ◽  
Current Confinement ◽  
Self Similar ◽  
The Wire

AbstractWe consider an axisymmetric steady flow of a viscous incompressible conducting fluid. The flow is induced by the point source of momentum and point electrode discharging the electric current, both of which are located at the end of a thin semi-infinite insulated wire. We seek the solution in the conical self-similar class where the velocity and magnetic field decrease as the inverse distance from the origin. The solution is obtained for various parameters of the problem, namely the Reynolds number, dimensionless electric current and Batchelor number (magnetic Prandtl number). A reverse flow along the wire occurs, leading to the confinement of the current density in the direction of the jet. If the Batchelor number is zero, the solution obtains a singularity at finite values of the current leading to its breakdown; otherwise, the solution exists at all parameter values. We derive the boundary-layer equations near the wire for large current values and obtain the solution. The pitchfork bifurcation with non-zero poloidal magnetic field occurs and causes the rotation of the fluid, which eliminates the current confinement effect. We describe the conditions when the solution for the swirling jet exists. The connection of this problem to the ones considered previously is discussed.

Exceptional nexus with a hybrid topological invariant

Science ◽  
2020 ◽  
Vol 370 (6520) ◽  
pp. 1077-1080 ◽  
Author(s):  
Weiyuan Tang ◽  
Xue Jiang ◽  
Kun Ding ◽  
Yi-Xin Xiao ◽  
Zhao-Qing Zhang ◽  
...  
Keyword(s):  
Parameter Space ◽  
Branch Point ◽  
Topological Charge ◽  
Higher Order ◽  
Topological Invariant ◽  
Wave Functions ◽  
Major Advance ◽  
Fundamental Understanding ◽  
Berry Phases ◽  
Complex Planes

Branch-point singularities known as exceptional points (EPs), which carry a nonzero topological charge, can emerge in non-Hermitian systems. We demonstrate with both theory and acoustic experiments an “exceptional nexus” (EX), which is not only a higher-order EP but also the cusp singularity of multiple exceptional arcs (EAs). Because the parameter space is segmented by the EAs, the EX possesses a hybrid topological invariant (HTI), which consists of distinct winding numbers associated with Berry phases accumulated by cyclic paths on different complex planes. The HTI is experimentally characterized by measuring the critical behaviors of the wave functions. Our findings constitute a major advance in the fundamental understanding of non-Hermitian systems and their topology, possibly opening new avenues for applications.

scholarly journals Chiral asymmetry during the EWPT from CP-violating scattering off bubble walls

2018 ◽  
Vol 172 ◽  
pp. 08001
Author(s):  
Alejandro Ayala ◽  
L. A. Hernández ◽  
Jordi Salinas
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Early Universe ◽  
Bubble Wall ◽  
First Order ◽  
Chiral Asymmetry

We compute a net electric current during a first order EWPT arising from the asymmetric propagation of fermion chiral modes due to a CP-violating interaction with the Higgs. The interaction is quantified in terms of a CP-violating phase in the bubble wall that separate both phases. We comment on the possibility of this current to generate a seed magnetic field and its implications for primordial magnetogenesis in the early Universe.

Zitterbewegung in cosmic string spacetime

2019 ◽  
Vol 34 (18) ◽  
pp. 1950135
Author(s):  
Natalia N. Konobeeva ◽  
Mikhail B. Belonenko
Keyword(s):  
Dirac Equation ◽  
Electric Current ◽  
Cosmic String ◽  
Curved Spacetime ◽  
Magnetic Flow ◽  
Motion Effect ◽  
Analytic Expression

In this paper, we investigate the trembling motion effect in the cosmic spacetime. The cosmic string was considered to be charged and carrying a magnetic flow. Zitterbewegung (ZB) is calculated based on the Dirac equation in the curved spacetime. An analytic expression for the electric current is obtained and analyzed.

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