Customer Reviews

Physical Foundations of Cosmology

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With the rising importance of cosmology has come an increasing flood of textbooks on modern cosmology. While I have not surveyed all the textbooks out there, many of those I have looked at suffered from serious problems. Recently, I had the opportunity of looking at Slava Mukhanov's new book on cosmology and I was so struck by its excellence that I am moved to post a review on Amazon, something I am not in the habit of doing. The bottom line is that I heartily recommend to any student or physicist serious about mastering modern cosmology. Mukhanov is one of the earliest pioneers in inflationary cosmology and a towering figure over the whole field, particularly when it comes to actual calculation, as compared to mere talk, of the density fluctuation spectrum.

Different people have different criteria for an outstanding textbook. I like a textbook to slice away all the obscure and unnecessary formalism shrouding the subject and to get through to the underlying concepts and the important physical ideas. So, dear reader, if you love heavy dry formalism that does not help you understand physics, then this book is not for you. (An aside: from a cursory glance at some of the reviews of physics books posted on Amazon I was amazed by the number of readers, apparently misinformed and misguided, more interested in mathematics and formalism than in understanding physics.)

There is a whole spectrum of books on cosmology. There are the giant compendia of every imaginable topic, but with almost nothing really derived, such as the book by Peacock. Then there are those books notorious for the amount of hype and hot air they blow. Such books apparently really appeal to people who want to "grasp" cosmology without doing any work; they could just read the hype and "be happy." On the opposite end of the spectrum is the book by Scott Dodelson, which is full of nitty gritty, the real stuff that you need to do detailed cosmic microwave background calculations, and which for that reason I highly recommend to students wanting to become professional cosmologists.

I have not read Mukhanov's book in its entirety. I read the parts on inflation and looked at his treatment of density perturbations. I really like his discussion of inflation, which carries the stamp of authority and deep understanding associated with a master who invented the subject. He cuts to the essential physics of the different approaches and wisely refrains from presenting the one thousand and one inflationary scenarios that have flooded (some would say, polluted) the literature. When he comes to density perturbations, he does it as simply as possible, and most importantly, correctly. Students should be aware of the fact that many of the well-known papers on the subject contain errors, as Mukhanov points out in a very helpful and biting footnote.

I recommend this book enthusiastically to all those serious about modern cosmology.

I've read the book and solved part of the problems in the course of a few months.

Let's start with the good. Viatcheslav Mukhanov is obviously an expert in theoretical cosmology, he is well known for quantizing the cosmological inhomogeneities. On 400 pages, he discusses all major topics like the necessary general relativity, hot universe (nucleosynthesis and recombination), the speculative ideas about the very early universe, inflation, inhomogeneities (their quantization and subsequent evolution), primordial quantum fluctuations, CMB, the gravitational wave background, and the CMB polarization. He is apparently a wizzard in obtaining semi-analytical approximations of differential equation solutions where others use numerical code. Experts in the field will appreciate the book as a primer for formulas and approximations. It feels like the author has shown his own view in the derivations, and often generalizes them compared to more elementary texts - for example the general relativity chapter is not limited to flat universes only and the inflation chapter discusses a rolling de Sitter space (H varies with time) not the easier exact de Sitter. The emphasis is on deriving approximate formulas in gory detail and interpretation of the results.

Now the bad for which I deducted one point. This books is definitely not for undegraduate or even middle level graduate student despite the author's claims. Understanding the GR chapter requires a course in GR and understanding the early universe chapter with its speculative fantasies coming from particle physics require a REALLY GOOD understanding of the ideas at frontiers of QFT - I had hard time telling what was going on conceptually behind the messy formulas.

The price to be paid for encompassing more general cases and deriving messy approximations is that there is no space left to carefully familiarize a beginner reader with the concepts - just mentioning something true is not enough to understand it deeply. Some of the high level explanations Mukhanov offers obviously assume an expert level reader. To a middle level reader like me, those explanations sound a little cryptic although I have no doubt they are true. What's the point though if the non-specialist will often go like 'huh ... what .... from where?'. I've written many of those in the book margins.

I found the author's claim that the text is easy to follow as algebra and manipulations completely NOT true - he often skips big chunks of algebra offering incomplete explanations how the next formula was derived. It takes huge amount of time to fill in the missing details, often requiring guessing the author's mind and on a few occasions I was simply unable to get it. I've written something like 100 pages just filling details.

I have been able to solve maybe 30% of the problems interspersed in the text. Many of them lack sufficient support in the text and there are no solutions or answers. It would be more pedagogical in my opinion to have at least solution outlines - what's the merit of a problem most readers won't be able to solve? Some of the problems require knowing approximation techniques like WKB, stationary phase, asymptotic series. Mukhanov could have written an appendix on these since he uses them so often.

After reading the book, I became familiar with the messy algebra at the frontier of cosmology. I've experienced lots of new concepts (not too deeply though) and seen powerfull approximations. The general logical picture of cosmology that I have hoped to gather from this book still remains a little chaotic - not sure what derives from where.

The book shoud be usefull for specialists looking for more generalized formulas and approximations. Mukhanov should work on more carefull explanation of concepts and the algebra if he wants that to be a book for beginners or middle level students. I suggest Scott Dodelson for that.

Recently I've found out that the Mukhanov textbook is almost a 1-to-1 copy of some of his overview articles [...]. Detail omission is common in published articles for the purposes of brevity but such style is not appropriate for a textbook.

Theories are written to explain observed phenomenon. They are then used to predict future discoveries. So long as the theory continues to work, it is accepted by the scientific community at large. Up until thirty or so years ago the model of the Cosmos was a fairly well agreed upon theory. Then slight problems began to appear, until in 1980-81 the author of this book conducted some experiments and developed theories that applied quantum fluctuations to the large scale structure of the universe.

This began the theory of inflationary cosmology that remedied several annoying little problems in the standard big bang model of the universe.

This is a textbook suitable for students in theoretical cosmology, physics, and astrophysics. It might be suitable for advanced undergraduates, but is more likely to be used in graduate level study. Some knowledge of general relativity and particle physics (and quantum field theory) is said by the author to be helpful but not necessary. I suppose that that's true, but by the end of the book you will certainly have some knowledge in this area. I'd recommend a bit of study in other books before tackling this one.

This book is a good single volume work on the modern view of cosmology. It can be used as a text on the subject. Further it contains a lot of information that will be very useful for even the best experts in the field.

Long-waited excellent textbook on phyical cosmology.
Contrary to many other texts on cosmology, which report
numerous facts, this one is self-consistent and derives
results from the first principles, economically
and often neatly. It covers main topics where
theoretical physics operates in cosmology.

I think this is the best conceptual book in cosmology,
I truly enjoy reading it.

I was really thinking of buying this book. But since it didn't have the
"search inside" feature, the decision is on hold.