Recent content by GeorgeDishman

This is a few years old now but I just came across lectures by Alan Guth in which he discusses this and answers my questions. He says there was sufficient time for the normal processes of thermal to act to produce equilibrium within a small patch before inflation then expanded to greater than...

Thank you, I eyeballed it with a missing zero as just under 0.2 instead of 0.02, my radius was too large by an order of magnitude. Sadly, it's about 12600km radius but 28000km off the line of sight. :-(

It was recently announced that J0740+6620 contains what is probably the most massive neutron star found to date: https://arxiv.org/pdf/1904.06759.pdf This paper concludes the companion to the MSP is a helium-atmosphere white dwarf: https://arxiv.org/pdf/1902.11150.pdf Based on a crude...

I've found this paper which probably meets my needs: https://iopscience.iop.org/article/10.1088/0004-637X/778/1/66 Equation (3) gives a range at formation for an isolated NS as: M_birth∼1.08–1.57M_☉ Presumably a star exceeding the Chandrasekhar limit would start to collapse but the implosion...

I'm looking for a paper I can cite that gives a lower credible limit for a neutron star mass, specifically to rule out an NS being below 0.5 Msun which I think should be possible. Do you have a specific source for your statement, it would be very helpful. Thanks. George

Does using the link affect the price at all? I'm hoping it's just the normal price, not 6% higher ;-) and the retailer is just providing commission for upping their volume.

I follow that, thanks. Although I am vaguely familiar with the equations, I need to get better at manipulating them that way so thanks for the tutorial :-)

Thanks for that, I'll read it through again. I'm a bit paranoid about not spreading disinformation or pseudo-science but being just an amateur, it's hard to keep comments like that in perspective. Your comment in parentheses explains the connection, thanks for that.

My comment was cautionary, based on this from Sean Carroll: http://www.preposterousuniverse.com/blog/2013/11/16/why-does-dark-energy-make-the-universe-accelerate/ However, in a FAQ from two years earlier he said: "Does that mean that dark energy has negative pressure? Yes indeed. Negative...

Almost. I'll say what I think and hope an expert will correct it if I'm wrong, I think my explanation might be somewhat contentious. Dark energy contributes to expansion two ways, through the energy content and through pressure both of which appear in the stress-energy tensor. Now some...

There are two competing parts to that, new radiation is being produced by stars and other sources all the time but that is a lesser effect, the main one is that the universe is expanding. The effect of that can easily be calculated, as distances increase in line with the scale fact ##a##...

Unfortunately, you haven't quite followed what the pop-sci sites say. When they talk of the universe being "like" a sphere, that is a 3D analogy to a 4D model. The 3D volume of our real universe is equivalent to only the surface of the higher dimension object. You are used to a normal sphere...

I think this paper analyses the effect you are describing or something very similar. Isn't it the shape of the magnitude vs. redshift curve (because we can only infer distance from redshift)?

Just reading between the lines, I wonder if the O.P. is confusing a 'flat' metric which can be perturbed with the 'absence' of any field where there would be nothing to perturb.

Thanks, I recognise those from the Lineweaver paper. The example I gave is outside our cosmological event horizon so the light will never reach us.