--%>

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 : How asteroids are formed Explain how

    Explain how asteroids are formed? Describe.

  • Q : Explain Gauss law for magnetic fields

    Gauss' law for magnetic fields (K.F. Gauss): The magnetic flux via a closed surface is zero (0); no magnetic charges present; in its differential form, div B = 0

  • Q : Explain Stern-Gerlach experiment

    Stern-Gerlach experiment (O. Stern, W. Gerlach; 1922): The experiment which explains the features of spin (that is intrinsic angular momentum) as a different entity apart from the orbital angular momentum.

  • Q : Explain Archimedes' principle What is 

    What is Archimedes' principle? A body which is submerged in a fluid is buoyed up by a force equivalent in magnitude to the weight of the fluid which is displaced, and directed upward all along a line via the c

  • Q : Define Hoop conjecture Hoop conjecture

    Hoop conjecture (K.S. Thorne, 1972): The conjecture (as so far unproven, although there is substantial proof to support it) that a non-spherical object, non-spherically compressed, will only form a black hole whenever all parts of the

  • Q : Define Occams razor or Ockhams razor

    Occam's [or Ockham's] razor (William of Occam [or Ockham]; c. 1340): It is the suggestion that the simpler a theory is the better. When two theories forecast the phenomena to the similar accuracy, then the one that is simpler is the better one. Furthe

  • Q : Define Einstein-Podolsky-Rosen effect

    Einstein-Podolsky-Rosen effect: EPR effect: Consider the subsequent quantum mechanical thought-experiment: Take a particle that is at rest and has spun zero (0). This spontaneously decays into two fermions (spin 1/2 particles), that stream away in the

  • Q : Define Kirkwood gaps Kirkwood gaps

    Kirkwood gaps (Kirkwood): The gaps in the asteroid belt, caused by the resonance effects from Jupiter. Similar gaps are also exists in Saturn's rings, due to the resonance effects of the shepherd moons.

  • Q : What is Magnetic monopole Magnetic

    Magnetic monopole: The hypothetical particle that comprises sources and sinks of the magnetic field. The magnetic monopoles have never been found, however would only cause pretty minor modifications to the Maxwell's equations. They also appear to be p

  • Q : Steps to the scientific notation

    Illustrate the steps to the scientific notation? Briefly illustrate the steps.