This tag applies to questions which deal with investigations of the string-theory landscape (defined as the space of solutions to the dynamical equations of string-theory) by physical, mathematical, or statistical methods.
5
votes
2answers
119 views
How can string theory work without supersymmetry?
This question is inspired from reading Mitchell Porter's nice answer here to a question asking why supersymmetry should be expected naturally. Among other things, he explains that since weak scale ...
2
votes
3answers
270 views
Could all strings be one single string which weaves the fabric of the universe?
This question popped out of another discussion, about if the photon needs a receiver to exist. Can a photon get emitted without a receiver? A universe containing only one electron was hypothetically ...
2
votes
1answer
243 views
Does a complete theory of quantum gravity require anthropic post-selection?
Does a complete theory of quantum gravity require anthropic post-selection? Certainly the black hole complimentarity and causal patch conjectures highlights the essential role of observers, at least ...
1
vote
2answers
310 views
Are the $10^{500}$ different string theories being whittled down?
An example of a test: Ask each variant whether its estimate of the electron mass lies within $\pm\,x\%$ of the known value. This surely can't take long per theory. Although $10^{500}$ is huge, ...
3
votes
0answers
50 views
Does the ensemble of effective Lagrangians in the String theory landscape mostly include gauge theories?
String theory false vacua can be described by effective Lagrangians at low energy. Is there generally a correspondence between these effective Lagrangians and SU(N) gauge theories? Or do the effective ...
2
votes
1answer
169 views
Why doesn't the anthropic principle select for N=2 SUSY compactifications with an exactly zero cosmological constant?
The party line of the anthropic camp goes something like this. There are at least $10^{500}$ flux compactifications breaking SUSY out there with all sorts of values for the cosmological constant. Life ...
5
votes
1answer
37 views
Interplay between the cosmological constant and “microscopic” properties of string vacua
As far as I understand, string phenomenology is usually concerned with compactifications of string theory, M-theory or F-theory in which the uncompactified dimensions form a 4-dimensional Minkowski ...
5
votes
1answer
42 views
Are there stable string theory vacua with non-minimal cosmological constant?
Naive reasoning suggests that a string theory vacuum with cosmological constant Lambda1 is always unstable as long as there is a string theory vacuum with cosmological constant Lambda2 < Lambda1 ...
0
votes
0answers
106 views
P-adic Numbers and Eternal Inflation
In October(??) 2011, Leonard Susskind gave a talk and with few other people wrote papers about p-adic numbers and measure problems in cosmology, see e.g. arXiv:1110.0496. Has there been any recent ...
1
vote
2answers
239 views
How seriously do string theorists take the “landscape”
The string theory landscape seems to this outside observer to be an intermediate step in the intellectual progress toward a more robust theory that explains why our one universe has the particular ...
6
votes
0answers
48 views
String landscape in different dimensions
For D = 11 large (uncompactified) spacetime dimensions, the only "string theory" vacuum is M-theory
For D = 10, there are 5 vacua. Or maybe it's more correct to say 4, since type I is S-dual to ...
