2,070 research outputs found
On Higher Derivative Couplings in Theories with Sixteen Supersymmetries
We give simple arguments for new non-renormalization theorems on higher
derivative couplings of gauge theories to supergravity, with sixteen
supersymmetries, by considerations of brane-bulk superamplitudes. This leads to
some exact results on the effective coupling of D3-branes in type IIB string
theory. We also derive exact results on higher dimensional operators in the
torus compactification of the six dimensional (0, 2) superconformal theory.Comment: 31 pages, 10 figures, section 2 reconstructured, new result in
section 3.2, additional clarifications adde
Supersymmetry Constraints and String Theory on K3
We study supervertices in six dimensional (2,0) supergravity theories, and
derive supersymmetry non-renormalization conditions on the 4- and 6-derivative
four-point couplings of tensor multiplets. As an application, we obtain exact
non-perturbative results of such effective couplings in type IIB string theory
compactified on K3 surface, extending previous work on type II/heterotic
duality. The weak coupling limit thereof, in particular, gives certain
integrated four-point functions of half-BPS operators in the nonlinear sigma
model on K3 surface, that depend nontrivially on the moduli, and capture
worldsheet instanton contributions.Comment: 47 pages, 4 figure
(2,2) Superconformal Bootstrap in Two Dimensions
We find a simple relation between two-dimensional BPS N=2 superconformal
blocks and bosonic Virasoro conformal blocks, which allows us to analyze the
crossing equations for BPS 4-point functions in unitary (2,2) superconformal
theories numerically with semidefinite programming. We constrain gaps in the
non-BPS spectrum through the operator product expansion of BPS operators, in
ways that depend on the moduli of exactly marginal deformations through chiral
ring coefficients. In some cases, our bounds on the spectral gaps are observed
to be saturated by free theories, by N=2 Liouville theory, and by certain
Landau-Ginzburg models.Comment: 56 pages, 14 figure
Duality Defect of the Monster CFT
We show that the fermionization of the Monster CFT with respect to
is the tensor product of a free fermion and the Baby Monster
CFT. The chiral fermion parity of the free fermion implies that the Monster CFT
is self-dual under the orbifold, i.e. it enjoys the
Kramers-Wannier duality. The Kramers-Wannier duality defect extends the Monster
group to a larger category of topological defect lines that contains an Ising
subcategory. We introduce the defect McKay-Thompson series defined as the
Monster partition function twisted by the duality defect, and find that the
coefficients can be decomposed into the dimensions of the (projective)
irreducible representations of the Baby Monster group. We further prove that
the defect McKay-Thompson series is invariant under the genus-zero congruence
subgroup of .Comment: 26+9 pages, 7 figure, 4 table
Duality defect of the monster CFT
We show that the fermionization of the Monster CFT with respect to â€_(2A) is the tensor product of a free fermion and the Baby Monster CFT. The chiral fermion parity of the free fermion implies that the Monster CFT is self-dual under the â€_(2A) orbifold, i.e. it enjoys the KramersâWannier duality. The KramersâWannier duality defect extends the Monster group to a larger category of topological defect lines that contains an Ising subcategory. We introduce the defect McKayâThompson series defined as the Monster partition function twisted by the duality defect, and find that the coefficients can be decomposed into the dimensions of the (projective) irreducible representations of the Baby Monster group. We further prove that the defect McKayâThompson series is invariant under the genus-zero congruence subgroup 16Dâ° of PSL(2,â€)
Bootstrapping Non-Invertible Symmetries
Using the numerical modular bootstrap, we constrain the space of 1+1d CFTs
with a finite non-invertible global symmetry described by a fusion category
. We derive universal and rigorous upper bounds on the lightest
-preserving scalar local operator for fusion categories such as
the Ising and Fibonacci categories. These numerical bounds constrain the
possible robust gapless phases protected by a non-invertible global symmetry,
which commonly arise from microscopic lattice models such as the anyonic
chains. We also derive bounds on the lightest -violating local
operator. Our bootstrap equations naturally arise from a "slab construction",
where the CFT is coupled to the 2+1d Turaev-Viro TQFT, also known as the
Symmetry TFT.Comment: 28 pages + reference
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 N=2
minimal models. The results are expressed in terms of integrals of conformal
blocks and evaluated numerically in the alpha' expansion. We find striking
agreements with up to 2-loop scattering amplitudes of massless gluons in 6D
SU(k) SYM at a Z_k invariant point on the Coulomb branch. We comment on the
issue of UV divergence at higher loop orders in the gauge theory and discuss
the implication of our results.Comment: 58 pages, 5 figures, 3 tables, comments added, references adde
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