Yuji Sugawara

Non-holomorphic modular forms and SL(2,R)/U(1) superconformal field theory

We study the torus partition function of the

Non-supersymmetric asymmetric orbifolds with vanishing cosmological constant

{{{{text{SL}}left( {2,mathbb{R}} right)}} left/ {{{text{U}}(1)}} right.}

Thermodynamics of superstring on near-extremal NS5 and effective Hagedorn behavior

SUSY gauged WZW model coupled to

Comments on non-holomorphic modular forms and non-compact superconformal field theories

mathcal{N} = 2

Lie algebra lattices and strings on T-folds

U(1) current. Starting from the path-integral formulation of the theory, we introduce an infra-red regularization which preserves good modular properties and discuss the decomposition of the partition function in terms of the

N = (0,4) quiver SCFT(2) and supergravity on AdS(3) x S**2

mathcal{N} = 2

“Analytic continuation” of = 2 minimal model

characters of discrete (BPS) and continuous (non-BPS) representations. Contrary to our naive expectation, we find a non-holomorphic dependence (dependence on

Compact Formulas for the Completed Mock Modular Forms

bar{tau }

Non-geometric backgrounds based on topological interfaces

) in the expansion coefficients of continuous representations. This non-holomorphicity appears in such a way that the anomalous modular behaviors of the discrete (BPS) characters are compensated by the transformation law of the non-holomorphic coefficients of the continuous (non-BPS) characters. Discrete characters together with the non-holomorphic continuous characters combine into real analytic Jacobi forms and these combinations exactly agree with the “modular completion” of discrete characters known in the theory of Mock theta functions [11].We consider this to be a general phenomenon: we expect to encounter “holomorphic anomaly” (

Non-BPS fractional branes with Bose-Fermi cancellation in asymmetric orbifolds

bar{tau }