To understand what is involved, some notes about landscapeology are in order.
- The whole business is based on wishful thought that physics for 2-D space-times in 10 or 11-D space could be transformed to that for 4-D space-times but it seems that 2 to 4 won't go.
- Landscape consists of huge number solutions of QFT limit with Calabi-Yau as internal space. This does not allow to fix 4-D space-time defining large dimensions.
- Swampland is identified as space-times consisting of 4-D space-time geometries not "derivable" from string model at the highly questionable QFT-GRT limit. There is an ambitious program trying to chart all space-times which do NOT emerge as solutions QFT-GRT limit. In TGD this program would mean finding all space-time surfaces which are NOT preferred extremals of the action principle. This new branch of physics could be called geography of Swampland.
- Anti-de-Sitter space (AdS) appearing in AdS/CFT correspondence would require wrong sign of cosmological constant. The challenge is to find solutions with dS as 4-D space-time. Of course, macroscopic space-time as dS space is also a notion deriving from the thinking that QFT+GRT as such describes the physics of string models in long length scales.
The situation in string models and theoretical particle physics has a long history of wrong hypothesis transformed soon to dogmas, and one should return to seventies, when GUT paradigm emerged - and probably as a great surprise for its proponents - became suddenly a dogma. Fast decision making and quick moves: this is the recipe for success in career building but in science it leads to a catastrophe. And in politics and economy too. It is not perhaps an accident that superstring business began at eighties when also yuppies took the power: in Finland their business games led to a deep economical depression and division of people to rich and poor: we are still suffering the consequences of the ensuing moral degeneration.
For a summary of earlier postings see Latest progress in TGD.