In general relativity, optical scalars refer to a set of three scalar functions (expansion), (shear) and (twist/rotation/vorticity) describing the propagation of a geodesic null congruence.[1][2][3][4][5]
In fact, these three scalars can be defined for both timelike and null geodesic congruences in an identical spirit, but they are called "optical scalars" only for the null case. Also, it is their tensorial predecessors that are adopted in tensorial equations, while the scalars mainly show up in equations written in the language of Newman–Penrose formalism.
^Eric Poisson. A Relativist's Toolkit: The Mathematics of Black-Hole Mechanics. Cambridge: Cambridge University Press, 2004. Chapter 2.
^Hans Stephani, Dietrich Kramer, Malcolm MacCallum, Cornelius Hoenselaers, Eduard Herlt. Exact Solutions of Einstein's Field Equations. Cambridge: Cambridge University Press, 2003. Chapter 6.
^Subrahmanyan Chandrasekhar. The Mathematical Theory of Black Holes. Oxford: Oxford University Press, 1998. Section 9.(a).
^Jeremy Bransom Griffiths, Jiri Podolsky. Exact Space-Times in Einstein's General Relativity. Cambridge: Cambridge University Press, 2009. Section 2.1.3.
^P Schneider, J Ehlers, E E Falco. Gravitational Lenses. Berlin: Springer, 1999. Section 3.4.2.
In general relativity, opticalscalars refer to a set of three scalar functions { θ ^ {\displaystyle \{{\hat {\theta }}} (expansion), σ ^ {\displaystyle...
Lorentzian manifolds admitting a geodesic null congruence with vanishing opticalscalars (expansion, twist and shear). A well known member of Kundt class is...
density J {\displaystyle \mathbf {J} } (a three-dimensional vector), the scalaroptical conductivity σ {\displaystyle \sigma } and the electric field vector...
approximations are available for analysing and designing optical systems. Most of these use a single scalar quantity to represent the electric field of the light...
An optical cavity, resonating cavity or optical resonator is an arrangement of mirrors or other optical elements that forms a cavity resonator for light...
optics, the superposition principle no longer holds. The first nonlinear optical effect to be predicted was two-photon absorption, by Maria Goeppert Mayer...
confined to a waveguide, and also in light waves in an optical fiber and in a laser's optical resonator. Transverse modes occur because of boundary conditions...
{\displaystyle {\vec {k}}={\vec {e}}_{0}+{\vec {e}}_{1}} has vanishing opticalscalars, but the null geodesic congruence generated by ℓ → = e → 0 − e → 1...
geometrically speaking, it is a null geodesic congruence with vanishing opticalscalars. Physically speaking, it serves as the wave vector defining the direction...
In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability...
entropy which can be identified with the area. 1972 – Sachs introduces opticalscalars and proves peeling theorem. 1972 – Rainer Weiss proposes concept of...
more than one atom in the smallest unit cell exhibit both acoustic and optical phonons. A phonon is the quantum mechanical description of an elementary...
discussion of the geometrical optical approximation in curved space-time and the opticalscalars transport equation. Gordon's optical metric was extended by...
optical system output image g is related to the input image f by convolving the input image with the optical impulse response function of the optical...
a constant amplitude sine wave applied to the input. For optical imaging devices, the optical transfer function is the Fourier transform of the point spread...
In physics, the optical theorem is a general law of wave scattering theory, which relates the zero-angle scattering amplitude to the total cross section...
the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. These optically anisotropic...
object interacts. For example, the term subwavelength-diameter optical fibre means an optical fibre whose diameter is less than the wavelength of light propagating...
A photonic metamaterial (PM), also known as an optical metamaterial, is a type of electromagnetic metamaterial, that interacts with light, covering terahertz...
A holographic optical element (HOE) is an optical component (mirror, lens, directional diffuser, etc.) that produces holographic images using principles...
effectively transport charge. Polarons are also important for interpreting the optical conductivity of these types of materials. The polaron, a fermionic quasiparticle...
In crystal optics, the index ellipsoid (also known as the optical indicatrix or sometimes as the dielectric ellipsoid) is a geometric construction which...
satellites. The vast majority of the world's oceans by area are optically deep. Optically deep water can still be relatively shallow water in terms of total...
Gauss magnetic law Magnetic dipole Magnetic field Magnetic flux Magnetic scalar potential Magnetic vector potential Magnetization Permeability Right-hand...
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