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Number of Results: 9 Search : expansion

accelerating expansion of the Universe gostareš-e šetâbande-ye giti Fr.: expansion accélérée de l'Univers → |

binomial expansion gostareš-e donâmin Fr.: expansion binomiale A rule for the expansion of an expression of the form x and y can be any → real numbers
and n is an → integer. The
general formula is known as the → binomial theorem. |

cosmic expansion gostareš-e keyhâni Fr.: expansion cosmique Same as the → |

expansion gostareš (#) Fr.: expansion 1) binomial expansion.Noun from → |

expansion of the Universe gostarš-e giti (#) Fr.: expansion de l'Univers The receding of galaxies from one another at a speed proportional to their separation, as
inferred by Edwin Hubble from the observed Doppler shift of distant galaxies.
→ |

expansion parameter pârâmun-e gostareš Fr.: paramètre d'expansion A → t
by _{0}R = aR. The expansion parameter represents
the history of expansion of the Universe._{0} |

free expansion phase fâz-e gostareš-e âzâd Fr.: phase d'expansion libre The first phase of → ^{2}, which
leads to
v = (2_{e}E_{SN} / M)_{e}^{(1/2)},
where M is the ejected mass.
The schematic structure of the SNR at this phase can be described as follows: behind
the strong → _{e}shock front
which moves outward into the ISM, compressed interstellar gas
accumulates forming a → shell of interstellar gas.
This shell of swept-up material in front of shock
does not represent a significant increase in the mass of the system.
After some time the accumulated mass equals the ejected mass of stellar
material, and it will start to affect the expansion of the SNR. By definition,
this is the end of the free
expansion phase, and the corresponding radius of the SNR, called
→ sweep-up radius,
R_{SW}, is defined by
M = (4π/3) _{e}R_{SW}^{3}ρ_{0},
that is R_{SW} =
(3M / 4πρ_{e}_{0})^{(1/3)},
where ρ_{0} is the initial density of the ISM.
This radius is reached at the
sweep-up time t_{SW} = R_{SW}/v.
The free expansion phase lasts some 100-200 years until the
mass of the material swept up by the shock wave exceeds the mass of
the ejected material. Then the following → _{e}snowplow phase
starts. |

post-Newtonian expansion gostareš-e pasâ-Newtoni Fr.: développement post-newtinien |

thermal expansion gostareš-e garmâyi Fr.: expansion thermique The change in dimensions of a material resulting from a change in temperature. |