scholarly journals Electromagnetic waves propagating in the string axiverse

2018 ◽  
Vol 2018 (4) ◽  
Author(s):  
Daiske Yoshida ◽  
Jiro Soda
Keyword(s):  
Dark Matter ◽  
Electromagnetic Field ◽  
Dispersion Relation ◽  
Resonance Frequency ◽  
Parametric Resonance ◽  
Electromagnetic Waves ◽  
Coupling Constant ◽  
Speed Of Light ◽  
Coherent Oscillation ◽  
Chern Simons

Abstract It is widely believed that axions are ubiquitous in string theory and could be dark matter. The peculiar features of axion dark matter are coherent oscillations and a coupling to the electromagnetic field through the Chern–Simons term. In this letter, we study the consequences of these two features of axions with mass in the range $10^{-13}\,{\rm eV}$ to $10^{3}\,{\rm eV}$. First, we study the parametric resonance of electromagnetic waves induced by the coherent oscillation of the axion. Since the resonance frequency is determined by the mass of the axion dark matter, if we detect this signal, we can get information on the mass of the axion dark matter. Second, we study the velocity of light in the background of the axion dark matter. In the presence of the Chern–Simons term, the dispersion relation is modified and the speed of light will oscillate in time. It turns out that the change in the speed of light would be difficult to observe. We argue that future radio wave observations of the resonance can give rise to a stronger constraint on the coupling constant and/or the density of the axion dark matter.

scholarly journals Gravitational Waves in Axion Dark Matter

Universe ◽  
2020 ◽  
Vol 6 (7) ◽  
pp. 89 ◽  
Author(s):  
Chong-Sun Chu ◽  
Jiro Soda ◽  
Daiske Yoshida
Keyword(s):  
Dark Matter ◽  
Gravitational Waves ◽  
Parametric Amplification ◽  
Coupling Constant ◽  
Speed Of Light ◽  
Coherent Oscillation ◽  
Axion Field ◽  
Specific Frequency ◽  
Chern Simons

Axion dark matter is interesting as it allows a natural coupling to the gravitational Chern–Simons term. In the presence of an axion background, the gravitational Chern–Simons term produces parity violating effects in the gravitational sector, in particular on the propagation of gravitational waves. Previously, it has been shown that the coherent oscillation of the axion field leads to a parametric amplification of gravitational waves with a specific frequency. In this paper, we focus on the parity violating effects of the Chern–Simons coupling and show the occurrence of gravitational birefringence. We also find deviation from the speed of light of the velocity of the gravitational waves. We give constraints on the axion-Chern–Simons coupling constant and the abundance of axion dark matter from the observation of GW170817 and GRB170817A.

scholarly journals Exploring the string axiverse and parity violation in gravity with gravitational waves

2018 ◽  
Vol 27 (09) ◽  
pp. 1850096 ◽  
Author(s):  
Daiske Yoshida ◽  
Jiro Soda
Keyword(s):  
Gravitational Waves ◽  
Circular Polarization ◽  
Parametric Resonance ◽  
Parity Violation ◽  
Coupling Constant ◽  
Coherent Oscillation ◽  
Chern Simons ◽  
Current Bound

We show that the parametric resonance of gravitational waves (GWs) occurs due to the axion coherent oscillation and the circular polarization of GWs is induced by the Chern–Simons coupling. However, we have never observed these signatures in the data of GWs. Using this fact, we give stringent constraints on the Chern–Simons coupling constant [Formula: see text] and the abundance of the light string axion. In particular, we improved the current bound [Formula: see text] by many orders of magnitude.

The Nature of Light

2017 ◽  
Author(s):  
Frank S. Levin
Keyword(s):  
Wave Phenomenon ◽  
Electromagnetic Waves ◽  
Speed Of Light ◽  
Particle Theory ◽  
Christiaan Huygens ◽  
Slit Experiment

Chapter 2 reviews answers to the question of what is light, starting with the ancient Greeks and ending in 1900 with the wave concept of Maxwell’s electrodynamics. For some ancient Greeks, light consisted of atoms emitted from surface of the object, whereas for others it was fire that either entered into or was emitted by eyes, although the latter possibility was effectively eliminated around the year 1000. Competing proposals well after then were that light is either a wave phenomenon or consists of particles, with Isaac Newton’s corpuscular (particle) theory prevailing by the end of the 1600s over the wave concept championed by Christiaan Huygens, who published the first estimate of the speed of light. In the early 1800s, Thomas Young’s two-slit experiment proved that light was a wave, a concept codified and firmly grounded through Maxwell’s theory of electromagnetic waves.

scholarly journals Hypersensitized Metamaterials Based on a Corona-Shaped Resonator for Efficient Detection of Glucose

2020 ◽  
Vol 11 (1) ◽  
pp. 103
Author(s):  
Yadgar I. Abdulkarim ◽  
Fahmi F. Muhammadsharif ◽  
Mehmet Bakır ◽  
Halgurd N. Awl ◽  
Muharrem Karaaslan ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Glucose Concentration ◽  
Electromagnetic Waves ◽  
Surface Current ◽  
Superior Performance ◽  
Promising Candidate ◽  
Efficient Detection ◽  
Circular Structure ◽  
Clear Shift ◽  
Current Electric Field

In this work, a new design for a real-time noninvasive metamaterial sensor, based on a corona-shaped resonator, is proposed. The sensor was designed numerically and fabricated experimentally in order to be utilized for efficient detection of glucose in aqueous solutions such as water and blood. The sensor was inspired by a corona in-plane-shaped design with the presumption that its circular structure might produce a broader interaction of the electromagnetic waves with the glucose samples. A clear shift in the resonance frequency was observed for various glucose samples, which implies that the proposed sensor has a good sensitivity and can be easily utilized to distinguish any glucose concentration, even though their dielectric coefficients are close. Results showed a superior performance in terms of resonance frequency shift (1.51 GHz) and quality factor (246) compared to those reported in the literature. The transmission variation level ∆|S21| was investigated for glucose concentration in both water and blood. The sensing mechanism was elaborated through the surface current, electric field and magnetic field distributions on the corona resonator. The proposed metamaterials sensor is considered to be a promising candidate for biosensor and medicine applications in human glycaemia monitoring.

scholarly journals ELECTROMAGNETIC INTERACTION OF ANYONS IN NONRELATIVISTIC QUANTUM FIELD THEORY

1994 ◽  
Vol 09 (06) ◽  
pp. 953-967 ◽  
Author(s):  
J. L. CORTÉS ◽  
J. GAMBOA ◽  
L. VELÁZQUEZ
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Interaction ◽  
Magnetic Coupling ◽  
Nonrelativistic Limit ◽  
Quantum Field ◽  
Nonrelativistic Quantum ◽  
Statistical Field ◽  
Mechanical Formulation ◽  
Dynamical Spin ◽  
Chern Simons

The nonrelativistic quantum-field-theoretic Lagrangian which describes an anyon system in the presence of an electromagnetic field is identified. A nonminimal magnetic coupling to the Chern–Simons statistical field as well as to the electromagnetic field together with a direct coupling between both fields are the nontrivial ingredients of the Lagrangian obtained from the nonrelativistic limit of the fermionic relativistic formulation. The results, an electromagnetic gyromagnetic ratio 2 for any spin together with a nontrivial dynamical spin-dependent contact interaction between anyons as well as the spin dependence of the electromagnetic effective action, agree with the quantum-mechanical formulation.

scholarly journals Superheavy dark matter and parametric resonance

1999 ◽  
Vol 449 (3-4) ◽  
pp. 230-236 ◽  
Author(s):  
Masato Arai ◽  
Hideaki Hiro-Oka ◽  
Nobuchika Okada ◽  
Shin Sasaki
Keyword(s):  
Dark Matter ◽  
Parametric Resonance ◽  
Superheavy Dark Matter

scholarly journals BOSE–FERMI EQUIVALENCE IN THREE-DIMENSIONAL NONCOMMUTATIVE SPACETIME

2008 ◽  
Vol 23 (35) ◽  
pp. 3015-3022
Author(s):  
K. M. AJITH ◽  
E. HARIKUMAR ◽  
M. SIVAKUMAR
Keyword(s):  
Partition Function ◽  
Gauge Field ◽  
Three Dimensional ◽  
Coupling Constant ◽  
Spin Factor ◽  
Noncommutative Spacetime ◽  
Chern Simons

We study the fermionisation of Seiberg–Witten mapped action (to order θ) of the λϕ4 theory coupled minimally with U(1) gauge field governed by Chern–Simons action. Starting from the corresponding partition function we derive nonperturbatively (in coupling constant) the partition function of the spin-1/2 theory following Polyakov spin factor formalism. We find that the dual interacting fermionic theory is nonlocal. This feature also persists in the limit of vanishing self-coupling. In θ → 0 limit, the commutative result is obtained.

scholarly journals Massive scalar field perturbation on Kerr black holes in dynamical Chern–Simons gravity

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Shao-Jun Zhang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Massive Scalar ◽  
Coupling Constant ◽  
Field Mass ◽  
Field Perturbation ◽  
Massive Scalar Field ◽  
Kerr Black Holes ◽  
Chern Simons

AbstractWe study massive scalar field perturbation on Kerr black holes in dynamical Chern–Simons gravity by performing a $$(2+1)$$ ( 2 + 1 ) -dimensional simulation. Object pictures of the wave dynamics in time domain are obtained. The tachyonic instability is found to always occur for any nonzero black hole spin and any scalar field mass as long as the coupling constant exceeds a critical value. The presence of the mass term suppresses or even quench the instability. The quantitative dependence of the onset of the tachyonic instability on the coupling constant, the scalar field mass and the black hole spin is given numerically.

Propagation of ultrashort optical pulses in anisotropic optical media with carbon nanotubes

2021 ◽  
pp. 2150197
Author(s):  
N. N. Konobeeva ◽  
M. B. Belonenko
Keyword(s):  
Carbon Nanotubes ◽  
Electromagnetic Field ◽  
Vector Potential ◽  
Pulse Shape ◽  
Electromagnetic Waves ◽  
Optical Pulses ◽  
Effective Equation ◽  
Ultrashort Optical Pulses ◽  
Optical Media ◽  
Crystal Type

In this paper, we investigate the evolution of electromagnetic waves in a nonlinear anisotropic optical medium with carbon nanotubes (CNTs). Based on Maxwell’s equation, an effective equation is obtained for the vector potential of the electromagnetic field, which takes into account different values of the velocity and polarization with two directions. The dependence of the pulse shape on the crystal type, as well as the angle between the electric field and the CNTs axis is revealed.

scholarly journals Dispersion of Localized Mode Polaritons in K3Cu(CN)4

1975 ◽  
Vol 30 (4) ◽  
pp. 537-540
Author(s):  
Wilhelm Nitsch
Keyword(s):  
Experimental Data ◽  
Dispersion Relation ◽  
Dispersion Curves ◽  
Coupling Constant ◽  
Localized Mode

Abstract The dispersion of polaritons of symmetry A1 and E is investigated in the region of four isotopic vibrations originating from C13- and N15 -atoms in their natural abundances. The measured dispersion curves are explained in terms of a theory for localized mode polaritons (LMP) developed by Ohtaka. The dispersion relation is generalized for a polyatomic crystal and applied to K3Cu(CN)4. The comparison of experimental data with calculated dispersion curves shows a quite satisfying agreement for a certain value of the coupling constant which is approximately the same for E-type and A1-type polaritons.

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