--%>
Assignment Help - homework help

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 Newton or SI unit of force

    Newton: N (after Sir I. Newton, 1642-1727): The derived SI unit of force, stated as the force needed to give a mass of 1 kg of an acceleration of 1 m/s2; it therefore has units of kg m/s2.

    		•
  • Q : Secondary electron image and back

    What is main difference between secondary electron image and the back scattered electron image? State briefly.

    		•
  • Q : Polar Materials The molecules of many

    The molecules of many dielectrics possess an electric dipole moment without having an external electric field. In such molecules centres of their positive and negative charges are displaced with respect to each other and therefore form a dipole. Such materials are kno

    		•
  • Q : Define Mole or SI unit of substance

    Mole: mol: The basic SI unit of substance, stated as the quantity of substance which contains as many elementary units (that is, atoms, molecules, ions, and so forth) as there are atoms in 0.012 kg of carbon-12.

    		•
  • Q : Define Photovoltaics Photovoltaics (PV)

    Photovoltaics (PV): It transform light directly into electricity. The typical current residential installation of 12m2 could produce around 1,300 kWh pa with a peak of around 1.9kW, though larger and more efficient installations are possibl

    		•
  • Q : Why electron and proton encompass

    Explain in short why electron and proton encompass similar charge while the proton is 1836 times heavier?

    		•
  • Q : Definition of Pascals principle Briefly

    Briefly state the definition of Pascal’s principle?

    		•
  • Q : Rest mass energy of the electron What

    What do you mean by the rest mass energy of the electron?

    		•
  • Q : What is Loschmidt constant or Loschmidt

    Loschmidt constant: Loschmidt number: NL: The total number of particles per unit volume of an ideal gas at standard pressure and temperature. It has the value of 2.687 19 x 1025 m-3.

    		•
  • Q : Explain Davisson-Germer experiment

    Davisson-Germer experiment (C.J. Davisson, L.H. Germer; 1927): The experiment which conclusively proved the wave nature of electrons; diffraction patterns were examined by an electron beam penetrating into the nickel target.

    		•