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Search: authors:"Chi-Ming Chang"

8 papers found.
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Romans supergravity from five-dimensional holograms

Abstract We study five-dimensional superconformal field theories and their holographic dual, matter-coupled Romans supergravity. On the one hand, some recently derived formulae allow us to extract the central charges from deformations of the supersymmetric five-sphere partition function, whose large N expansion can be computed using matrix model techniques. On the other hand, the...

Carving out the end of the world or (superconformal bootstrap in six dimensions)

We bootstrap \( \mathcal{N}=\left(1,0\right) \) superconformal field theories in six dimensions, by analyzing the four-point function of flavor current multiplets. Assuming E 8 flavor group, we present universal bounds on the central charge C T and the flavor central charge C J . Based on the numerical data, we conjecture that the rank-one E-string theory saturates the universal...

Bootstrap, universality and horizons

We present a closed form expression for the semiclassical OPE coefficients that are universal for all 2D CFTs with a “weak” light spectrum, by taking the semiclassical limit of the fusion kernel. We match this with a properly regularized and normalized bulk action evaluated on a geometry with three conical defects, analytically continued in the deficit angles beyond the range for...

An index for ray operators in 5d E n SCFTs

We construct an index for BPS operators supported on a ray in five dimensional superconformal field theories with exceptional global symmetries. We compute the E n representations (for n = 2, . . . , 7) of operators of low spin, thus verifying that while the expression for the index is only SO(2n − 2) × U(1) invariant, the index itself exhibits the full E n symmetry (at least up...

Bootstrapping 2D CFTs in the semiclassical limit

We study two-dimensional conformal field theories in the semiclassical limit. In this limit, the four-point function is dominated by intermediate primaries of particular weights along with their descendants, and the crossing equations simplify drastically. For a four-point function receiving sufficiently small contributions from the light primaries, the structure constants...

Deformations with maximal supersymmetries part 2: off-shell formulation

Continuing our exploration of maximally supersymmetric gauge theories (MSYM) deformed by higher dimensional operators, in this paper we consider an off-shell approach based on pure spinor superspace and focus on constructing supersymmetric deformations beyond the first order. In particular, we give a construction of the Batalin-Vilkovisky action of an all-order non-Abelian Born...

Little string amplitudes (and the unreasonable effectiveness of 6D SYM)

We study tree level scattering amplitudes of four massless states in the double scaled little string theory, and compare them to perturbative loop amplitudes in six-dimensional super-Yang-Mills theory. The little string amplitudes are computed from correlators in the cigar coset CFT and in \( \mathcal{N} \) = 2 minimal models. The results are expressed in terms of integrals of...

The Incidence of Japanese Encephalitis in Taiwan—A Population-Based Study

Background A mass Japanese encephalitis (JE) vaccination program targeting children was launched in Taiwan in 1968, and the number of pediatric JE cases substantially decreased thereafter. The aim of this study was to elucidate the long-term trend of JE incidence, and to investigate the age-specific seroprevalence of JE-neutralizing antibodies. Methodology/Principal Findings A...