Tensors | Differential geometry | Tensors in general relativity
In physics and mathematics, a pseudotensor is usually a quantity that transforms like a tensor under an orientation-preserving coordinate transformation (e.g. a proper rotation) but additionally changes sign under an orientation-reversing coordinate transformation (e.g., an improper rotation), which is a transformation that can be expressed as a proper rotation followed by reflection. This is a generalization of a pseudovector. To evaluate a tensor or pseudotensor sign, it has to be contracted with some vectors, as many as its rank is, belonging to the space where the rotation is made while keeping the tensor coordinates unaffected (differently from what one does in the case of a base change). Under improper rotation a pseudotensor and a proper tensor of the same rank will have different sign which depends on the rank being even or odd. Sometimes inversion of the axes is used as an example of an improper rotation to see the behaviour of a pseudotensor, but it works only if vector space dimensions is odd otherwise inversion is a proper rotation without an additional reflection. There is a second meaning for pseudotensor (and likewise for pseudovector), restricted to general relativity. Tensors obey strict transformation laws, but pseudotensors in this sense are not so constrained. Consequently, the form of a pseudotensor will, in general, change as the frame of reference is altered. An equation containing pseudotensors which holds in one frame will not necessarily hold in a different frame. This makes pseudotensors of limited relevance because equations in which they appear are not invariant in form. (Wikipedia).
An general explanation of the underactive thyroid.
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Differential Equations | Homogeneous linear equations with constant coefficients
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Lec 8 - Phys 237: Gravitational Waves with Kip Thorne
Watch the rest of the lectures on http://www.cosmolearning.com/courses/overview-of-gravitational-wave-science-400/ Redistributed with permission. This video is taken from a 2002 Caltech on-line course on "Gravitational Waves", organized and designed by Kip S. Thorne, Mihai Bondarescu and
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The term "tensor" is often misunderstood. Let's figure out what they are through vector examples like velocity, angular momentum, the stress tensor, and the electromagnetic tensor. Brilliant for 20% off: http://brilliant.org/ScienceAsylum ________________________________ VIDEO ANNOTATIONS/
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Is an Ice Age Coming? | Space Time | PBS Digital Studios
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Noether's Theorem and The Symmetries of Reality
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Narcissism is the word we routinely use to describe someone self-satisfied and arrogant. But what do we really mean by the word – and are we applying it correctly? If you like our films, take a look at our shop (we ship worldwide): https://goo.gl/YfXSQO Join our mailing list: http://bit.ly
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In this video I remind you of the derivatives of a few transcendental functions such as exponent x and the trigonometric functions.
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Lec 8b - Phys 237: Gravitational Waves with Kip Thorne
Watch the rest of the lectures on http://www.cosmolearning.com/courses/overview-of-gravitational-wave-science-400/ Redistributed with permission. This video is taken from a 2002 Caltech on-line course on "Gravitational Waves", organized and designed by Kip S. Thorne, Mihai Bondarescu and
From playlist Caltech: Gravitational Waves with Kip Thorne - CosmoLearning.com Physics
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Start learning today, click https://brilliant.org/blackpenredpen/ to check out Brillant.org. First 200 people to sign up will get 20% off your annual premium subscription! This is why the area is t/2 https://youtu.be/h-gKfQkHQSA read more on hyperbolic functions: https://brilliant.org/w
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