# Holographic constraints on CFT energies
Wiseman found a series of evidence that the free energy decreases when one deforms the spatial sphere or the flat space (periodically) of the QFT.
## Refs
- [[2016#Fischetti, Hickling, Wiseman]]
- bounds on local energy density
- [[2019#Cheamsawat, Gibbons, Wiseman]]
- bounds from studying BHs directly
## Non-holographic studies
- [[FischettiWiseman2017]]
- direct calculations in 2+1 dim CFT on curved backgrounds
## Results
- 2+1d QFT (space either $R^2$ or $S^2$)
- perturbatively
- $\Delta F<0$ for free scalar and Dirac theories
- likewise for holographic CFT on flat space
- non-perturbatively
- also holds at $T=0$ for holographic CFTs on any space
- for $T>0$ holds for *energy* for periodic flat space deformations, for free theories it seems to hold (numerically)
## Related topics
- [[0231 Bulk solutions for CFTs on non-trivial geometries]]