Recent content by windy miller

https://arxiv.org/abs/2503.14452

What do the latest results from the Atacama Cosmology Telescope mean for inflation? Are simple models like Staroninsky ruled out? What is favoured?

Thanks for this guys

I understand that most physicists reject the idea the idea that Big Bang is a singularity. I see, for example, in this survey, most reject associating the Big Bang with a singularity. https://arxiv.org/pdf/2503.15776. However , if we hypothetically took a realist view of singularities. I(n...

thanks guys, thought that was the case.

There is a new paper on singularities https://arxiv.org/abs/2501.17910 My understanding is that most cosmologists dont take singularities very seriously as we need a quantum theory fo gravity to resolve them. In particular the statement that time ends in a black hole or began at the big bang...

Let me know if you find it thanks.

Variations in the tamperatureo of the CMB are 1 part in 100,00. My understanding is that this was first measured by COBE, But was this value predicted? What were the ranges of estimates for its value before it was measured?

thanks

I understand inflation is thought to predict primordial gravitational waves although their strength is undetermined by the theory with some models of inflation predicting them to be strong and others so weak they can never be detected. However , this paper claims that if we detect a background...

Thanks for taking the time to respond but my post was not really trying to have the concept of the HZ explained but rather to try and get some history . So the questions are 1. did anyone predict the existence of exoplanets based on athropics or not 2 if they did when did they? 3 when was the...

Earth's distance from the sun is said to lie in a small Habitable Zone (HZ) . How did it come to be in such a fortunate position? It seems that someone in the past could have asked this question and concluded on the basis of anthropics there must be a large number of planets in our galaxy. My...

Alan Guth says it about 3 minutes into this video But he is talking about the flatness problem and says the initial expansion rate. So that's what i guess they must be the same thing, are they?

So my understanding is that the claim that the expansion rate of the universe is delicately fine tuned and the flatness of the geometry is delicately fine tuned is one and the same claim. Is that correct. I am aware that inflation can solve this problem but that is not my questions. Many thanks

As I understand it, the flatness problem of Bob Dicke, says a flat universe in unstable and so has to be set very precisely in the early universe to give us the flat universe we see today. Is this the same problem as saying the expansion rate had to be finely tuned and if so how are the two...