On asymptotic behaviour in truncated conformal space approach

Anatoly Konechny*, Dermot McAteer

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)
51 Downloads (Pure)


The Truncated conformal space approach (TCSA) is a numerical technique for finding finite size spectrum of Hamiltonians in quantum field theory described as perturbations of conformal field theories. The truncation errors of the method have been systematically studied near the UV fixed point (when the characteristic energy related to the coupling is less than the truncation cutoff) where a good theoretical understanding has been achieved. However numerically the method demonstrated a good agreement with other methods for much larger values of the coupling when the RG flow approaches a new fixed point in the infrared. In the present paper we investigate this regime for a number of boundary RG flows testing the leading exponent and truncation errors. We also study the flows beyond the first fixed point which have been observed numerically but yet lack a theoretical understanding. We show that while in some models such flows approximate reversed physical RG flows, in other models the spectrum approaches a stable regime that does not correspond to any local boundary condition. Furthermore we find that in general the flows beyond the first fixed point are very sensitive to modifications of the truncation scheme.

Original languageEnglish
Article number44
JournalJournal of High Energy Physics
Issue number9
Early online date6 Sept 2019
Publication statusPublished - Sept 2019


  • Boundary Quantum Field Theory
  • Field Theories in Lower Dimensions
  • Non-perturbative Effects
  • Renormalization Group

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


Dive into the research topics of 'On asymptotic behaviour in truncated conformal space approach'. Together they form a unique fingerprint.

Cite this