The “critical density” is the average density of matter required for the Universe to just halt its expansion, but only after an infinite amount of time. This means that the universe’s expansion would come to a halt, and not recollapse. A universe with…
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The Second Friedmann Equation describes the acceleration or deceleration of the expansion (or contraction). It describes the forces pushing or pulling on the expansion.
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“An electric charge is the property of matter where it has more or fewer electrons than protons in its atoms. Electrons carry a negative charge and protons carry a positive charge. Matter is positively charged if it contains more protons than electrons,…
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Continuum mechanics deals with the mechanical behavior of materials – modeled as a continuous mass, rather than as a set of discrete particles. One of the centers of research in continuum mechanics is at the University of Birmingham.
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Angular Momentum is the rotational analog of linear momentum. It is denoted by the lowercase omega symbol in particle physics. It may also be denoted elsewhere by the symbol as in: ; Where is mass; is velocity; and, is radius.
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The stress–energy tensor is a tensor physical quantity. A vector quantity is a tensor quantity that contains two components. A scalar quantity is a tensor quantity that contains only one component. These are special cases of tensors, being the simplest kind. But…
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A perfect fluid can be completely characterized by its rest frame mass density and isotropic pressure . Specifically, perfect fluids have no shear stresses, viscosity, or heat conduction. Real fluids are “sticky” and contain (and conduct) heat. Perfect fluids are idealized models…
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Dimensional analysis is the analysis of relationships between different physical quantities by identifying their base quantities and units of measure and tracking these dimensions as calculations or comparisons are performed.
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Poisson’s equation is an elliptic partial differential equation used widely in theoretical physics.
read moreQuantum chaos is a branch of physics which studies how chaotic classical dynamical systems can be described in terms of quantum theory. The primary question that quantum chaos seeks to answer is: “What is the relationship between quantum mechanics and classical chaos?”…
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