--%>

Explain Cosmological constant

Cosmological constant (Lambda): The constant mentioned to the Einstein field equation, proposed to admit the static cosmological solutions. At the time the present philosophical view was steady-state model of the space, where the Universe has been around for unlimited time. Prior analysis of the field equation pointed that the general relativity permitted dynamic cosmological models only (ones which are either contracting or expanding), however no static models. Einstein mentioned the most natural aberration to the field equation which he could think of: the addition of a term proportional to the space time metric tensor, g, with constant of proportionality being the cosmological constant as:

G + Lambda g = 8 pi T.

Hubble's afterward discovery of the expansion of the Universe pointed that the introduction of the cosmological constant was needless; had Einstein believed what his field equation was stating him, he could have declared the expansion of the Universe as perhaps the supreme and most convincing prediction of general relativity; he termed this the "greatest blunder of my life."

   Related Questions in Physics

  • Q : Define Ehrenfest paradox Ehrenfest

    Ehrenfest paradox (Ehernfest, 1909): The special relativistic "paradox" including a fast rotating disc. As any radial segment of the disc is perpendicular to the direction of motion, there must be no length contraction of the radius;

  • Q : Explain Pascals principle Pascal's

    Pascal's principle: The pressure exerted to an enclosed incompressible static fluid is transmitted undiminished to all portions of the fluid.

  • Q : Black-hole dynamic laws or laws of

    Explain  laws of black-hole dynamics or First law of black hole dynamics and Second law of black hole dynamics? 

    Q : Explain Curie-Weiss law Curie-Weiss law

    Curie-Weiss law (P. Curie, P.-E. Weiss): A more broad form of Curie's law that states that the susceptibility, khi, of a paramagnetic substance is associated to its thermodynamic temperature T by the equation:

    Q : Define Uniformity principle Uniformity

    Uniformity principle (E.P. Hubble): The principle which the laws of physics here and now are not dissimilar, at least qualitatively, from the laws of physics in preceding or future epochs of time, or somewhere else in the Universe. This principle was

  • Q : Why tea kettle sing What is the reason

    What is the reason that the tea kettle sing? Briefly state the reason.

  • Q : Problem on Adiabatic law When air is

    When air is compressed adiabatically the law connecting the absolute temperature T and the pressure P is of the form T = A.Pn where A and N are constants. Show by drawing a suitable linear graph that the experimental dat

  • Q : What do you mean by the term cardiac

    What do you mean by the term cardiac output? Briefly explain it.

  • Q : Define Universal constant of gravitation

    Universal constant of gravitation: G The constant of proportionality in the Newton’s law of universal gravitation and that plays a comparable role in Sir Einstein's general relativity. This is equivalent to the 6.672 x 10-1

  • Q : Define Le Chateliers principle Le

    Le Chatelier's principle (H. Le Chatelier; 1888): When a system is in equilibrium, then any modification imposed on the system tends to shift the equilibrium state to decrease the consequence of that applied change.