Use the Friedmann equations to show that the deceleration parameter go and the density parameter N are related through qo = 2/2 for a universe containing only dust.
Q: e gravitational energy of a pair of colliding galaxies , each of mass 10 Mo separated by a distance…
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Q: Suppose the energy density of the cosmological constant is equal to the present critical density En…
A: Einstein came up with the universal or cosmological constant to balance the calculations in his…
Q: Assume a flat Friedmann-Robertson-Walker universe, and that the density parameters for matter…
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Q: Suppose a hypothetical universe is expanding (at some moment in time) at a rate of H. At this same…
A: Given that for a universe Rate of expanding H = 90 km s-1 Mpc-1 And at this time the density ρ =…
Q: Calculate the critical density of our universe.
A: Our universe is expanding and critical density is defined as the average density of matter that is…
Q: The critical mass density needed to just halt the expansion of the universe is approximately 10-26…
A: Given critical mass density needed to halt the expansion of the universe is ρcrirical = 10-26 kg/m3
Q: Explain what is meant by the term cosmological redshift, and contrast it with the Doppler shift that…
A: A Doppler red shift is the expansion of the wavelength and decrease in the frequency when an the…
Q: Critical density of a universe is found to be 6×10-27 kg/m. Estimate the value of Hubble constant.
A: It was observed that galaxies are moving away from each other and the farther they are faster they…
Q: In the early universe, the formation of л* or лº was through thermal interactions. What is the…
A: As mass-energy equivalence says that mass and energy are the same, mass can be converted into energy…
Q: a) If you were to measure the distances and recessional velocities to nearby galaxies, you would…
A: (a) Introduction: Peculiar motion refers to the motion of an object related to a Galactic rest…
Q: An alternative Universe is dominated by a single type of matter with equation of state parameter w =…
A: Given Equation of state parameter ω=-0.1 l=60
Q: The critical mass density needed to just halt the expansion of the universe is approximately 10-26…
A: Given that,The critical mass density = 10-26 kg/m3Average mass = 7 eV/c2As we know that,If m is in…
Q: Show that in matter dominated universe density behave as p x (1+z)3 , in radiation dominated as px…
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Q: Explain why the cosmological principle requires that H0 must have the same value everywhere in…
A: Given Explain why the cosmological principle requires that H0 must have the same value everywhere in…
Q: The mass of the neutrino plays an important role in the universe. Suppose the mass of two neutrinos…
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Q: Describe the Feynman diagram for the exchange of a between a proton and a neutron.
A: When a proton decays into a neutron then an exchange particle is W+ And the other products are…
Q: If a galaxy is 9.3 Mpc away from Earth and recedes at 508 km/s, what is H, (in km/s/Mpc)? 54.62…
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Q: The present number density of electrons in the Universe is the same as that of protons, about 0.2…
A: The present number density of electrons = 0.2m-3. Long before the formation of microwave background,…
Q: Calculate the temperature for which the ratio of free protons to free neutrons in the early stages…
A: Given information: The ratio of free protons to free neutrons is 7.0 It is mentioned that the…
Q: Figure 3 shows a 3.0-kg block that starts from rest at the top of a plane inclined 0-30° above the…
A: Given: The mass of the block is m = 3 kg The angle of inclination of the ramp is 300 The block takes…
Q: The Lyman a line in a galaxy's spectrum was observed to be 208 nm. Calculate the Doppler redshift.
A: When there is relative motion between observer and source the wavelength observed will e shift. When…
Q: The energy density ϵ in radiation is related to its temperature by ϵ=αT4. Compute the temperature…
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Q: ase of this unive hat nearby galaxie stance. He then me
A: From Ryden equation, a(θ)=Ω02Ω0 -1 (1-cosθ)t(θ)=Ω02H0 (Ω0 -1)32 (θ-sinθ) θ= 0 to 2π Here, a=1.
Q: Estimate the critical density of the universe if the Hubble's constant was 100 km/s/Mpc.
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Q: Compute a numerical value (in units of protons/m3 ) for the critical density of our Universe. How…
A: The critical density for the Universe is given by, ρ = 3H28πG where H is the Hubble constant and G…
Q: The largest known redshift attributed to a specifi c molecule is z = 6.42 from the CO molecule in…
A: Given data: The red-shift parameter is z=6.42. The red-shift parameter z and relative velocity…
Q: Calculate the temperature of the universe when photons can no longer disassociate deuterons. Use the…
A: Given: The photons can no longer disassociate deuterons.
Q: An electron jumps from n=3 to n=2 in a hydrogen atom in a distant galaxy, emitting light. If we…
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Q: Estimate the critical density of the universe if the Hubble's constant was 50 km/s/Mpc.
A: The minimum density that is required to stop the expansion of the universe is defined as the…
Q: According to the version of the Big Bang Theory without a Cosmological Constant (and without Dark…
A: Hubble's Law states that as the universe is expanding in all directions, the receding velocity of an…
Q: Assume a flat Friedmann-Robertson-Walker universe. Calculate the redshift z at which the temperature…
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Q: If the average density of the Universe is small compared with the critical density, the expansion of…
A: According to Hubble’s law v = HR The expression for R is R=vΔt Thus, v=HvΔtΔt=1H Here, ∆t is the…
Q: Assume the average density of the universe is 0.1 of the critical density needed for closure. What…
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Q: Consider the following line element, ds^2 = −dt^2 + a^2(t) (dx^2 + dy^2) + b^2(t) dz^2, where a(t)…
A: The objective of the question is to determine whether the given line element obeys the Cosmological…
Q: The rest wavelength of the Hα transition of atomic hydrogen is 656.3 nm (recall that 1 nm=10-9 m).…
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Q: (a) What Hubble constant corresponds to an approximate age of the universe of 1010 y? To get an…
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Q: Assume a power law for the scale factor a = Ctn, where C is a constant. (a) For what values of n are…
A: Given data: Scale factor is, a=Ctn. C is a constant.
Q: Assuming the matter temperature equalled the radiation temperature at the recombination epoch,…
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Q: Using Ho = = 20.8 km/s/Mly and assuming the expansion rate has been constant, find out how long the…
A: It is observed that the galaxies in our universe are moving away from each other. This expansion of…
Q: Assume a flat Friedmann-Robertson-Walker universe, and that the density parameters for matter,…
A:
Q: If some unknown cause of red shift—such as light becoming “tired” from traveling long distances…
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Q: Consider the following line element, ds^2 = −dt^2 + a^2 (t) (dx^2 + dy^2 ) + b^2 (t) dz^2 , where…
A: Required: State whether or not this line element obeys the Cosmological Principle, if applied to…
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