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arXiv:2104.00281 · Journal of High Energy Physics

Characters of irrelevant deformations

Shouvik Datta, Yunfeng Jiang

Published Jul 1, 2021• 6 citations
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Abstract

Abstract We analyse the $$ T\overline{T} $$ T T ¯ deformation of 2d CFTs in a special double-scaling limit, of large central charge and small deformation parameter. In particular, we derive closed formulae for the deformation of the product of left and right moving CFT characters on the torus. It is shown that the 1/c contribution takes the same form as that of a CFT, but with rescalings of the modular parameter reflecting a state-dependent change of coordinates. We also extend the analysis for more general deformations that involve $$ T\overline{T} $$ T T ¯ , $$ J\overline{T} $$ J T ¯ and $$ T\overline{J} $$ T J ¯ simultaneously. We comment on the implications of our results for holographic proposals of irrelevant deformations.

DOI
10.1007/jhep07(2021)162

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TT‾,JT‾,TJ‾ T\overline{T},J\overline{T},T\overline{J} TT,JT,TJ partition sums from string theory
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TT‾ T\overline{T} TT deformed partition functions
A bstract We demonstrate the presence of modular properties in partition functions of TT‾ T\overline{T} TT T T ¯ deformed conformal field theories. These properties are verified explicitly for the deformed free boson. The modular features facilitate a derivation of the asymptotic density of states in these theories, which turns out to interpolate between Cardy and Hagedorn behaviours. We also point out a sub-sector of the spectrum that remains undeformed under the TT‾ T\overline{T} TT T T ¯ flow. Finally, we comment on the deformation of the CFT vacuum character and its implications for the holographic dual.
We demonstrate the presence of modular properties in partition functions of TT deformed conformal field theories. These properties are verified explicitly for the deformed free boson. The modular features facilitate a derivation of the asymptotic density of states in these theories, which turns out to interpolate between Cardy and Hagedorn behaviours. We also point out a sub-sector of the spectrum that remains undeformed under the TT flow. Finally, we comment on the deformation of the CFT vacuum character and its implications for the holographic dual.
Modular covariance and uniqueness of JT‾ J\overline{T} JT deformed CFTs
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