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Anomalous Absorption
Anomaly may refer to: Science Natural *Anomaly (natural sciences) **Atmospheric anomaly **Geophysical anomaly Medical *Congenital anomaly (birth defect), a disorder present at birth ** Physical anomaly, a deformation of an anatomical structure ***Congenital vertebral anomaly, any of several malformations of the spine **Collie eye anomaly, eye disease of dogs *** Coronary artery anomaly, a congenital abnormality in the heart ***Ebstein's anomaly, a congenital heart defect in which the opening of the tricuspid valve is displaced *** Uhl anomaly, a congenital heart disease affecting the myocardial muscle *** Vaginal anomalies Biology * Anomalous, a species of moth in the Noctuid family * Chromosome anomaly, a disorder caused by a structural error in a chromosome or an atypical number of chromosomes *Genetic anomaly, a disorder caused by mutation *Teratology, the study of developmental anomalies Physics *Anomalous diffusion is the movement of molecules from a region of lower conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomaly (natural Sciences)
In the natural sciences, especially in atmospheric and Earth sciences involving applied statistics, an ''anomaly'' is a persisting deviation in a physical quantity from its expected value, e.g., the systematic difference between a measurement and a trend or a model prediction.Wilks, D.S. (1995) ''Statistical Methods in the Atmospheric science'', Academic Press. (page 42) Similarly, a standardized anomaly equals an anomaly divided by a standard deviation. A group of anomalies can be analyzed spatially, as a map, or temporally, as a time series. It should not be confused for an isolated outlier. There are examples in atmospheric sciences and in geophysics. Calculation The location and scale measures used in forming an anomaly time-series may either be constant or may themselves be a time series or a map. For example, if the original time series consisted of daily mean temperatures, the effect of seasonal cycles might be removed using a deseasonalization filter. Robust statis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomalon
:Anomalon ''is also the type genus of the ichneumon-wasp subfamily Anomaloninae.'' See '' Anomalon (genus)''. In physics, an anomalon is a hypothetical type of nuclear matter that shows an anomalously large reactive cross section. They were first noticed in experimental runs in the early 1980s as short tracks in film emulsions or plastic leaf detectors connected to medium-energy particle accelerators. The direction of the tracks demonstrated that they were the results of reactions taking place within the accelerator targets, but they stopped so quickly in the detectors that no obvious explanation for their behavior could be offered. A flurry of theoretical explanations followed, but over time a series of follow-up experiments failed to find strong evidence for the anomalons, and active study of the topic largely ended by the late 1980s. Description Early particle accelerators generally consisted of three parts, the accelerator, a metal target, and some sort of detector. Detectors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flyby Anomaly
The flyby anomaly is a discrepancy between current scientific models and the actual increase in speed (i.e. increase in ''kinetic energy'') observed during a planetary flyby (usually of Earth) by a spacecraft. In multiple cases, spacecraft have been observed to gain greater speed than scientists had predicted, but thus far no convincing explanation has been found. This anomaly has been observed as shifts in the S-band and X-band Doppler and ranging telemetry. The largest discrepancy noticed during a flyby has been 13 mm/s. Observations Gravitational assists are valuable techniques for Solar System exploration. Because the success of such flyby maneuvers depends on the exact geometry of the trajectory, the position and velocity of a spacecraft during its encounter with a planet is continually tracked with great precision by the Deep Space Network (DSN). The flyby anomaly was first noticed during a careful inspection of DSN Doppler data shortly after the Earth flyby of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eccentric Anomaly
In orbital mechanics, the eccentric anomaly is an angular parameter that defines the position of a body that is moving along an elliptic Kepler orbit. The eccentric anomaly is one of three angular parameters ("anomalies") that define a position along an orbit, the other two being the true anomaly and the mean anomaly. Graphical representation Consider the ellipse with equation given by: :\frac + \frac = 1, where ''a'' is the ''semi-major'' axis and ''b'' is the ''semi-minor'' axis. For a point on the ellipse, ''P'' = ''P''(''x'', ''y''), representing the position of an orbiting body in an elliptical orbit, the eccentric anomaly is the angle ''E'' in the figure. The eccentric anomaly ''E'' is one of the angles of a right triangle with one vertex at the center of the ellipse, its adjacent side lying on the ''major'' axis, having hypotenuse ''a'' (equal to the ''semi-major'' axis of the ellipse), and opposite side (perpendicular to the ''major'' axis and touching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apsidal Precession
In celestial mechanics, apsidal precession (or apsidal advance) is the precession (gradual rotation) of the line connecting the apsides (line of apsides) of an astronomical body's orbit. The apsides are the orbital points closest (periapsis) and farthest (apoapsis) from its primary body. The apsidal precession is the first time derivative of the argument of periapsis, one of the six main orbital elements of an orbit. Apsidal precession is considered positive when the orbit's axis rotates in the same direction as the orbital motion. An apsidal period is the time interval required for an orbit to precess through 360°. History The ancient Greek astronomer Hipparchus noted the apsidal precession of the Moon's orbit (as the revolution of the Moon's apogee with a period of approximately 8.85 years); it is corrected for in the Antikythera Mechanism (circa 80 BCE) (with the supposed value of 8.88 years per full cycle, correct to within 0.34% of current measurements). The pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apsis
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parity Anomaly
In theoretical physics a quantum field theory is said to have a parity anomaly if its classical action is invariant under a change of parity of the universe, but the quantum theory is not invariant. This kind of anomaly can occur in odd-dimensional gauge theories with fermions whose gauge groups have odd dual Coxeter numbers. They were first introduced by Antti J. Niemi and Gordon Walter Semenoff in the letterAxial-Anomaly-Induced Fermion Fractionization and Effective Gauge-Theory Actions in Odd-Dimensional Space-Times and by A. Norman Redlich in the letteGauge Noninvariance and Parity Nonconservation of Three-Dimensional Fermionsand the articlParity violation and gauge noninvariance of the effective gauge field action in three dimensions It is in some sense an odd-dimensional version of Edward Witten's SU(2) anomaly in 4-dimensions, and in fact Redlich writes that his demonstration follows Witten's. The anomaly in 3-dimensions Consider a classically parity-invariant gau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mixed Anomaly
In theoretical physics, a mixed anomaly is an example of an anomaly: it is an effect of quantum mechanics — usually a one-loop diagram — that implies that the classically valid general covariance and gauge symmetry of a theory of general relativity combined with gauge fields and fermionic fields cannot be preserved simultaneously in the quantum theory. The adjective "mixed" usually refers to a mixture of a gravitational anomaly and gauge anomaly, but may also refer to a mixture of two different gauge groups tensored together, like the ''SU(2)'' and the ''U(1)'' of the Standard Model. The anomaly usually appears as a Feynman diagram with a chiral fermion running in the loop (a polygon) with ''n−k'' external gravitons and ''k'' external gauge bosons attached to the loop where n=1+D/2 where D is the spacetime dimension. Chiral fermions only occur in even spacetime dimensions. For example, the anomalies in the usual 4 spacetime dimensions arise from triangle Feynman diagra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Konishi Anomaly
In theoretical physics, the Konishi anomaly is the violation of the conservation of the Noether current associated with certain transformations in theories with N=1 supersymmetry. More precisely, this transformation changes the phase of a chiral superfield. It shouldn't be confused with the R-symmetry that also depends on the fermionic superspace variables. The divergence of the corresponding Noether current for the Konishi transformation is nonzero but can be exactly expressed using the superpotential. Konishi anomaly is named after its discoverer Kenichi Konishi, who is currently full professor of Theoretical Physics at the Physics Department E.Fermi of University of Pisa, Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical .... References * Supersymmetric quantum field ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Anomaly
In theoretical physics, a gravitational anomaly is an example of a gauge anomaly: it is an effect of quantum mechanics — usually a one-loop diagram—that invalidates the general covariance of a theory of general relativity combined with some other fields. The adjective "gravitational" is derived from the symmetry of a gravitational theory, namely from general covariance. A gravitational anomaly is generally synonymous with ''diffeomorphism anomaly'', since general covariance is symmetry under coordinate reparametrization; i.e. diffeomorphism. General covariance is the basis of general relativity, the classical theory of gravitation. Moreover, it is necessary for the consistency of any theory of quantum gravity, since it is required in order to cancel unphysical degrees of freedom with a negative norm, namely gravitons polarized along the time direction. Therefore, all gravitational anomalies must cancel out. The anomaly usually appears as a Feynman diagram with a chira ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Anomaly
In theoretical physics, a global anomaly is a type of anomaly: in this particular case, it is a quantum effect that invalidates a large gauge transformation that would otherwise be preserved in the classical theory. This leads to an inconsistency in the theory because the space of configurations which is being integrated over in the functional integral involves both a configuration and the same configuration after a large gauge transformation has acted upon it and the sum of all such contributions is zero and the space of configurations cannot be split into connected components for which the integral is nonzero. Alternatively, the existence of a global anomaly implies that the measure of Feynman's functional integral cannot be defined globally. The adjective "global" refers to the properties of a group that are detectable via large gauge or diffeomorphism transformations, but are not detectable locally via infinitesimal transformations. For example, all features of a discrete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gauge Anomaly
In theoretical physics, a gauge anomaly is an example of an anomaly: it is a feature of quantum mechanics—usually a one-loop diagram—that invalidates the gauge symmetry of a quantum field theory; i.e. of a gauge theory. All gauge anomalies must cancel out. Anomalies in gauge symmetries lead to an inconsistency, since a gauge symmetry is required in order to cancel degrees of freedom with a negative norm which are unphysical (such as a photon polarized in the time direction). Indeed, cancellation occurs in the Standard Model. The term gauge anomaly is usually used for vector gauge anomalies. Another type of gauge anomaly is the gravitational anomaly, because coordinate reparametrization (called a diffeomorphism) is the gauge symmetry of gravitation. Calculation of the anomaly Anomalies occur only in even spacetime dimensions. For example, the anomalies in the usual 4 spacetime dimensions arise from triangle Feynman diagrams. Vector gauge anomalies In vector gauge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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