Bojowald with movies (Loop Cosmology paper)

[marcus]

today Martin Bojowald posted a paper on Loop Quantum Cosmology

http://arxiv.org/abs/gr-qc/0601085

it is over 100 pages long and has movies to illustrate

more info on the "Rovelli's program" REFERENCE LINK THREAD here:
https://www.physicsforums.com/showthread.php?p=888994#post888994

the movies are down at the bottom of the sidebar menu

 

[marcus]

Analogies prove nothing, but they can make one feel more at home.

Sigmund Freud Introductory Lectures on Psychoanalysis

Bojowald has raised the bar for style quality of Loop writing. (also remember that Oriti quoted Homer Simpson and Livine used lines from the Babylonian Talmud.

More Bojo epigraphsmanship on page 12:

Je abstrakter die Wahrheit ist, die du lehren willst, um so mehr musst du noch die Sinne zu ihr verführen.

(The more abstract the truth you want to teach is, the more you have to seduce to it the senses.)

Friedrich Nietzsche Beyond Good and Evil

**page 54**

Because irrational numbers are always the result of calculations, never the result of direct measurement, might it not be possible in physics to abandon irrational numbers altogether and work only with the rational numbers? That is certainly possible, but it would be a revolutionary change. . . . At some future time, when much more is known about space and time and the other magnitudes of physics, we may find that all of them are discrete.

Rudolf Carnap An Introduction to the Philosophy of Science

**page 75**

Dies alles dauerte eine lange Zeit, oder eine kurze Zeit: denn, recht gesprochen, gibt es für dergleichen Dinge auf Erden keine Zeit.

(All this took a long time, or a short time: for, strictly speaking, for such things no time on Earth exists.)

Friedrich Nietzsche Thus Spoke Zarathustra

==========================
I skipped several choice quotes, one from the Egyptian Book of the Dead
Loop Quantum Cosmology
http://arxiv.org/abs/gr-qc/0601085
https://www.physicsforums.com/showthread.php?p=888994#post888994
the movies are down at the bottom of the sidebar menu of the Living Reviews version

 

[marcus]

On page 47 Bojowald cites work in preparation, by himself, Abhay Ashtekar, and Josh Willis. this is reference [146]

citations [95] and [189] are also to work in preparation
(works cited "in prep." can give a clue as to current research interests)

the only cited CDT paper I noticed was Dittrich and Loll on the CDT picture of black holes----Bojo reference [195]
-----------------

the papers mentioned around page 47 have importance outside Cosmology---they deal with the general problem of the low-energy limit of LQG: how to get realistic results out of the theory at low energy and large scale. Reference [145] is to an earlier Bojowald paper about this.
He shows a true instinct for going after major road-block problems, or so i think. One should keep aware of what he chooses to investigate outside Cosmology.

 

[Chronos]

I should have known you would not miss this gem, marcus. Apologies for the double post. This will surely be one of the most important loop papers of the year.

 

[marcus]

I like this paper a lot. It is very clearly and thoughtfully written. So far I have only read a part of it. And I haven't watched any of the computer animation diagrams ("movies") yet.

this paper does a good job explaining what regular LQG is, and then explaining how that is simplified down and specialized to cosmology, so you see how LQC relates to the full LQG theory.

It would not be bad as a short introduction to the full theory.
So far, this paper seems to me to be a classic. Even though it is a review and not a new-results paper it may turn out to my favorite for the year.

===============

Another good paper already from 2006 is by Oriti and Ryan
(3D spinfoam QG and matter)
it just came out today---abstract posted here:
https://www.physicsforums.com/showpost.php?p=899398&postcount=443
https://www.physicsforums.com/showthread.php?p=899398#post899398