Well, I wasn’t aware that Paul Steinhardt is one of the critics of inflation theory. I knew that there are critical acclaims though. For example Neil Turok and Roger Penrose have proposed that there is something wrong in inflation theory.

Of course I’m still convinced of the theory of inflation, and so far I haven’t seen anything that would even raise a serious doubt. Admittedly there are a few questions regarding the very get-go of inflation; I’m not sure whether we ever get to answer this (and similar) questions. Maybe (just maybe) we’ll get more insights with improved instruments such as the JWST or even gravitational signatures which allow us to “poke” even further back in history, very much closer to the beginning of time itself.

I am curious, how can JWST bring insight into the inflation?

Hi Martin,
Thanks for asking! The JWST is designed to have significantly improved sensors for the IR, hence can look deeper into the past with a better resolution than the HST. From this, the early period of our universe is expected to be seen with greater clarity than ever before. Structure formation, motion (!) and general qualities of the very first galaxies should be identifiable, giving more detailed information about this important phase in our history. Probably most importantly, the data should help to clear the so-called Hubble tension, giving us a better idea of the expansion directly after the CMBR (surface of last scattering).
Hope this answers your question?!

Hello Klaus,
Many thanks for great response! By chance I am a member of the JWST high redshift team but I am not a theoretical physicist, so I am eager to learn the details. Could you be more specific how the galaxy formation would give insight to the inflation? The JWST can perform deep field observations but not a survey to get the large scale structures map. If there is a way to (dis)prove inflation by deep field it would be fantastic! Is there a direct link between early galaxy formation and details of the inflation?

Hi Martin,
Very well: First of all, I might remind you of an article from the ESA-HST page, dtd. 13 Oct 2016 (heic 1620), telling us that the HST revealed data of about roughly 10 times more galaxies in the observable universe than previously thought. As the HST is relatively weak the further it looks back, the results were only sketchy; the JWST will do much better than that, looking back not “just” some 13 billion lightyears, but about 1 billion lightyears further, up to the first formation of stars (and the said galaxies) and possibly peering into the realm of the “Dark Age”. Studying the formation process allows further insights into the “dark sector” of the universe, i.e. the workings of dark matter and the dark energy, the latter most likely being responsible for the expansion “drive” of the universe, hence giving us the Hubble factor (it is NOT a constant!). With this, we have (hopefully) the Hubble factor from the CMBR, then – new or with greater accuracy – the value of the first billion years.This would close a gap which right now is a wild area of equally wild speculation, even suggesting we might need “new physics” or should be fiddling around with various tuning methods of dark energy.
And, btw: I’m not so sure that we cannot achieve the large scale structures map! Of course, it won’t be with the JWST alone, but it gets us the beginning of the process, which is invaluable for the entire map, a large part of which we have already charted.

I am afraid that the theory of eternal inflation (TEF) throws up more questions than answers. At least in Big Bang (BB), the initial accumulation and blowing up of energy, created enough kinetic energy for inflation/expansion, while TEF has no such initial fireworks envisaged. Then how the TEF will work? We definitely need a new theory, like the cooking of rice is not over as yet and the bubbles which escape to the surface create a phenomenon of little BBs and are local to that part of the melting pot. The half cooked rice is akin to the Dark Matter and once the process of cooking is complete the Dark Matter will fill all the void.

No, the quantum microfoundations of inflation appear to imply eternal hyperinflation, contradicting what we are looking for.

I think that these initial conditions are very natural.The eternal inflating universe follows in a natural way from very simply and generic conditions.

I personally have a problem with eternal inflation in the fact that it might not be eternal after all. If I understand correctly the way stuff decays, on average stuff decays 50% after a half-time has passed. However, it could decay 30% or 99% or 100%, just by chance. And if this is true, then if you have eternity to wait, at some point all the inflationary material will decay everywhere in the multiverse, just by chance – it will just happen that 100% of the inflationary material will decay and the previously believed “eternal” inflation will stop. Am I making any mistake, here?

No, it was near but not perfectly fit with all properties of the universe. I think, we need some more knowledge of quantum world to solve this.

I appreciate the insights from Klaus Cormann regarding how much we have to look forward to from the JWST. Hopefully, the added information will help answer these questions. Until the, I am not ready to dismiss the theory of inflation.

Hello Ladies and Gentlemen,

The regions that do not make it to the end are occupying most of the space.

Regions making it to the end are atypical.

The Big Bang does`t make it to the end of inflation theory.

So it is unlikely.

Still curious

I think the inflation theory is truth but it have just some small wrongs by developing we can make it have more truth and predictions.

I’ve always had problems reconciling the inflationary model. So this fits in my mind easier, infinity doesn’t start, it always was and will be.

Not yet, although with the Quantum Physics (Quantum Fluctuations) can undermine the inflation theory

The theory of inflation holds strong in its capacity to resolve critical challenges within the standard Big Bang model. It offers solutions for issues like the uniformity of the universe, the formation of structures, and the universe’s flatness. Nevertheless, challenges remain, including the absence of direct observational confirmation and the proliferation of diverse inflation models. Although promising, further research and observations are necessary to solidify its validity and refine its nuances.