Swampland (physics)


In physics, the term swampland refers to effective low-energy physical theories which are not compatible with string theory. Physical theories which are compatible are called "landscape". Recent developments in string theory suggest that the string theory landscape of false vacua is vast.
It is natural to ask if the landscape is as vast as allowed by consistent-looking effective field theories. Some authors suggest that is not the case and that the landscape is surrounded by an even larger swampland of consistent-looking semiclassical effective field theories, which are actually inconsistent.
Some proposed swampland criteria are the following:
It has been shown that the swampland criteria are inconsistent with the idea of single-field slow-roll inflation given current cosmological data.