- #1
jal
- 549
- 0
WOW! wow! What a paper!
Tell Martin Bojowald (and those that he cited), that I’m throwing a party and supplying the refreshments and photo ops. (They can get an expense account from their depts.).
Marcus, you can forget all the other papers …. This is the most influential paper … and it will be for years to come.
I want to tell all the “seekers” about this paper.
I want to tell the whole world!
Contrarily to Martin Bojowald, I can take a definite position and say that his paper presents a strong argument as to why the “inflaton” is not needed.
http://arxiv.org/PS_cache/arxiv/pdf/0705/0705.4398v1.pdf
The Dark Side of a Patchwork Universe
Martin Bojowald
30 may 2007
A complete understanding of the universe currently faces several problems, most of which are occasionally expected to be solved by some version of quantum gravity. This also applies to the dark energy problem.
Schematically, one has a picture where space is presented as a discrete structure building up from a small state at the big bang to a highly refined, nearly continuous fabric today. The evolution picture is thus that of an irregular lattice structure which changes in internal time by elementary changes of geometry.
Note: just add one more unit every once in a while
From the point of view of quantum field theory on curved space-times one can effectively view the finiteness of vacuum energy in loop quantum gravity as a cut-off provided by the underlying discrete structure of loop quantum gravity. On the grounds of dimensional arguments one would expect that the cut-off occurs at Planckian values of energy or length, which would certainly result in the well known mismatch between the predicted and observed cosmological constants.
Note: I would like to see arguments why the cutoff cannot be at 10^18 (gluon interaction sizes/length)
It is to be expected that vacuum energy in this formalism does not only depend on the matter state but also on quantum geometry.
In fact, such a quantum geometry epoch of inflation typically does not last long enough to provide all 60 e-foldings required for successful structure formation.
Moreover, such an isotropic model with only inverse volume corrections is not
very accurate at large volume because it does not fully take into account the dynamical discreteness of space manifesting itself in lattice refinements determined by the elementary moves of a Hamiltonian constraint.
Rather, during expansion the discrete structure of space subdivides as described in Sec. 2 which can be modeled by adding new small, discrete patches resulting from new vertices of graphs. When the number of patches increases with volume, their size stays nearly constant or could even decrease.
francesca
I did not even look at the other papers that you mentioned. Martin Bojowald’s paper was just tooooo much!
jal
Tell Martin Bojowald (and those that he cited), that I’m throwing a party and supplying the refreshments and photo ops. (They can get an expense account from their depts.).
Marcus, you can forget all the other papers …. This is the most influential paper … and it will be for years to come.
I want to tell all the “seekers” about this paper.
I want to tell the whole world!
Contrarily to Martin Bojowald, I can take a definite position and say that his paper presents a strong argument as to why the “inflaton” is not needed.
http://arxiv.org/PS_cache/arxiv/pdf/0705/0705.4398v1.pdf
The Dark Side of a Patchwork Universe
Martin Bojowald
30 may 2007
A complete understanding of the universe currently faces several problems, most of which are occasionally expected to be solved by some version of quantum gravity. This also applies to the dark energy problem.
Schematically, one has a picture where space is presented as a discrete structure building up from a small state at the big bang to a highly refined, nearly continuous fabric today. The evolution picture is thus that of an irregular lattice structure which changes in internal time by elementary changes of geometry.
Note: just add one more unit every once in a while
From the point of view of quantum field theory on curved space-times one can effectively view the finiteness of vacuum energy in loop quantum gravity as a cut-off provided by the underlying discrete structure of loop quantum gravity. On the grounds of dimensional arguments one would expect that the cut-off occurs at Planckian values of energy or length, which would certainly result in the well known mismatch between the predicted and observed cosmological constants.
Note: I would like to see arguments why the cutoff cannot be at 10^18 (gluon interaction sizes/length)
It is to be expected that vacuum energy in this formalism does not only depend on the matter state but also on quantum geometry.
In fact, such a quantum geometry epoch of inflation typically does not last long enough to provide all 60 e-foldings required for successful structure formation.
Moreover, such an isotropic model with only inverse volume corrections is not
very accurate at large volume because it does not fully take into account the dynamical discreteness of space manifesting itself in lattice refinements determined by the elementary moves of a Hamiltonian constraint.
Rather, during expansion the discrete structure of space subdivides as described in Sec. 2 which can be modeled by adding new small, discrete patches resulting from new vertices of graphs. When the number of patches increases with volume, their size stays nearly constant or could even decrease.
francesca
I did not even look at the other papers that you mentioned. Martin Bojowald’s paper was just tooooo much!
jal
