Unanswered Questions
131 questions with no upvoted or accepted answers
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Force to fix $\sigma_{8}$ or $A_{s}$ for Forecasts
In the context of Forecasts with Fisher's formalism, I make vary cosmological parameters to compute the elements of the Fisher matrix.
First, I generate with CAMB code a linear power spectrum. Then, ...
CommunityBot
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2
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57
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Is there a way to calculate how much damage black hole merger shockwaves inflict on nearby objects?
Black hole mergers lose respective rotational energy during a merger. I understand that the energy 'emitted' is scattered as gravitational 'energy' that can henceforth be detected by gravitational ...
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What is the meaning of ellipticity of a galaxy being more than 1?
I was recently doing a project on calculating ellipticities of galaxies using SDSS data. I downloaded the stokes parameter values (q and u) from data
$e = 1 - \frac{b}{a} = 1 - \frac{1 - \sqrt{Q^2 + ...
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How to write a normalized, dimensionless form of Binet's relativistic equation?
$$\frac{\delta^2 u}{\delta \theta^2} + u = \frac{\mu}{h^2} + 3 \mu u^2$$
This is Binet's relativistic equation. Here $u = 1/r$ where $r$ is the radial distance, and $\mu$ is the reduced mass of the ...
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A high-temperature isolated neutron star could be super-Eddington?
If the surface temperature of a young neutron star is hot enough, say, several KeV, its blackbody radiation could be super-Eddington?
Did any paper discuss this scenario before?
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What are the procedures and protocols to use with Gauss'method and personal observations?
I would like to use the Gauss' method to determine the orbit of planets of solar system.
I would like to calculate their orbits with personal observations.
What is the methodology/procedure/protocol ...
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What's the profound reason(s) why the star formation rate drives the scatter of the mass-metallicity relation in galaxies?
Since decades it's well known that a correlation between stellar mass and metallicity (Z; both stellar and gas-phase Z, but here I focus on the gas-phase Z) exists (e.g., Tremonti+04; analysis of >...
CommunityBot
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Predicting Temperature Variation on Planets with High Eccentricity or Long Diurnal Periods
Whew! That title was a mouth-full, but accurate I hope. What I'm trying to figure out is a model for calculating the approximate temperature variation for a generally earth-like planet (similar ...
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87
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What is known about the angular momentum distribution within galaxy clusters?
I recently saw a 3D-plot of proper motions of galaxies within the Laniakea super-cluster (https://sketchfab.com/models/754cb85550fb42588175f8a215718521). Is a similar 3D map of the vector field of ...
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Question about finding energy density of a fermionic-bosonic gas
We know that energy density is given by this formula:
$$u = \frac{1}{V}\int_0^\infty\epsilon_pf(\epsilon_p) g_s V/h^3 4\pi p^2 dp$$
Where $\epsilon_p=pc$ for relativistic particles. also $f(\...
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Why does the axial tilt & the rotation speed of Saturn & Jupiter vary so much?
I have seen Jupiter and its 4 largest moons in a telescope, several times. The moons are always aligned in a line. This is fine. Very interesting. But.. in case of Saturn, not only that we can see its ...
- 126k
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cross-matched SDSS-WISE catalog
Please where can I find cross-matched SDSS and WISE dataset for a machine learning project?
(Galaxy-star-qso classification task)
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Determining Time Based on Arc Seconds
So our arc day starts at 20°41'32 which is midnight (0:00) and ends 24 hours later at 21°42'42. According to my calculations it traveled 0 degrees, 59 minutes, and 30 seconds or 3570 arc seconds in 24 ...
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Calculating the absolute magnitude of a solar system body
I am trying to calculate the absolute magnitude of a solar system object, given its albedo, and assuming all of its luminosity comes from reflecting light from the sun. Using $L_{sun}$ = solar ...
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What would be the new Equation of motion if the magnetic field's origin is shifted from the origin of a co-rotating spherical polar coordinates?
The equation of motions due to the dipole magnetic force of a planet in a frame corotating with the planet and origin at the centre of planet assumed to be sphere components wise are given as below:
\...
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