A
bstract
According to a conjecture, all 5
d
SCFTs should be obtainable by rank- preserving RG flows of 6
d
SCFTs compactified on a circle possibly twisted by a background for the discrete global ...symmetries around the circle. For a 6
d
SCFT admitting an F-theory construction, its untwisted compactification admits a dual M-theory description in terms of a “parent” Calabi-Yau threefold which captures the Coulomb branch of the compacti- fied 6
d
SCFT. The RG flows to 5
d
SCFTs can then be identified with a sequence of flop transitions and blowdowns of the parent Calabi-Yau leading to “descendant” Calabi-Yau threefolds which describe the Coulomb branches of the resulting 5
d
SCFTs. An explicit description of parent Calabi-Yaus is known for untwisted compactifications of rank one 6
d
SCFTs. In this paper, we provide a description of parent Calabi-Yaus for untwisted compactifications of arbitrary rank 6
d
SCFTs. Since 6d SCFTs of arbitrary rank can be viewed as being constructed out of rank one SCFTs, we accomplish the extension to arbi- trary rank by identifying a prescription for gluing together Calabi-Yaus associated to rank one 6d SCFTs.
Despite recent advance in bioinspired adhesives, achieving strong adhesion and sealing hemostasis in aqueous and blood environments is challenging. A hyperbranched polymer (HBP) with a hydrophobic ...backbone and hydrophilic adhesive catechol side branches is designed and synthesized based on Michael addition reaction of multi‐vinyl monomers with dopamine. It is demonstrated that upon contacting water, the hydrophobic chains self‐aggregate to form coacervates quickly, displacing water molecules on the adherent surface to trigger increased exposure of catechol groups and thus rapidly strong adhesion to diverse materials from low surface energy to high energy in various environments, such as deionized water, sea water, PBS, and a wide range of pH solutions (pH = 3 to 11) without use of any oxidant. Also, this HBP adhesive (HBPA) exhibits a robust adhesion to fractured bone, precluding the problem of mismatched surface energy and mechanical properties. The HBPA's adhesion is repeatable in a wet condition. Intriguingly, the HBPA is capable of gluing dissimilar materials with distinct properties. Importantly, introducing long alkylamine into this modular hyperbranched architecture contributes to formation of an injectable hemostatic sealant that can rapidly stop visceral bleeding, especially hemorrhage from deep wound.
A hyperbranched polymer adhesive fabricated using a ternary Michael addition reaction of hydrophobic multi‐vinyl monomers with dopamine demonstrates strong underwater adhesion to diverse materials without any oxidant. This is due to water‐triggered fast coacervation and increased outward exposure of catechols. Introducing long‐chain alkylamine contributes to the formation of an injectable hemostatic sealant that can rapidly stop visceral bleeding, especially hemorrhage from deep wound.
This paper introduces a general perturbative quantization scheme for gauge theories on manifolds with boundary, compatible with cutting and gluing, in the cohomological symplectic (BV–BFV) formalism. ...Explicit examples, like abelian BF theory and its perturbations, including nontopological ones, are presented.
We introduce a gluing orbit property, weaker than specification, for both continuous maps and flows. We prove that flows with the C1-robust gluing orbit property are uniformly hyperbolic and that ...every uniformly hyperbolic flow satisfies the gluing orbit property. We also prove a level-1 large deviations principle and a level-2 large deviations lower bound for semiflows with the gluing orbit property. As a consequence we establish a level-1 large deviations principle for hyperbolic flows and every continuous observable, and also a level-2 large deviations lower bound. Finally, since many non-uniformly hyperbolic flows can be modeled as suspension flows we also provide criteria for such flows to satisfy uniform and non-uniform versions of the gluing orbit property.
G2-Monopoles are solutions to gauge theoretical equations on G2-manifolds. If the G2-manifolds under consideration are compact, then any irreducible G2-monopole must have singularities. It is then ...important to understand which kind of singularities G2-monopoles can have. We give examples (in the noncompact case) of non-Abelian monopoles with Dirac type singularities, and examples of monopoles whose singularities are not of that type. We also give an existence result for Abelian monopoles with Dirac type singularities on compact manifolds. This should be one of the building blocks in a gluing construction aimed at constructing non-Abelian ones.
Unitarity methods in AdS/CFT Meltzer, David; Perlmutter, Eric; Sivaramakrishnan, Allic
The journal of high energy physics,
03/2020, Letnik:
2020, Številka:
3
Journal Article
Recenzirano
Odprti dostop
A
bstract
We develop a systematic unitarity method for loop-level AdS scattering amplitudes, dual to non-planar CFT correlators, from both bulk and boundary perspectives. We identify cut operators ...acting on bulk amplitudes that put virtual lines on shell, and show how the conformal partial wave decomposition of the amplitudes may be efficiently computed by gluing lower-loop amplitudes. A central role is played by the double discontinuity of the amplitude, which has a direct relation to these cuts. We then exhibit a precise, intuitive map between the diagrammatic approach in the bulk using cutting and gluing, and the algebraic, holographic unitarity method of 1 that constructs the non-planar correlator from planar CFT data. Our analysis focuses mostly on four-point, one-loop diagrams — we compute cuts of the scalar bubble, triangle and box, as well as some one-particle reducible diagrams — in addition to the five-point tree and four-point double-ladder. Analogies with S-matrix unitarity methods are drawn throughout.
Abstract
Concrete is manmade multiphase composite where coarse granular materials are embedded in a hard matrix of binder, filling the space between the aggregate particles and gluing them all ...together that strengthens with time on hydration. Addition of nanoparticles further enhances the properties of the concrete such as early strength, refined micro structure and enhanced durability. Nanoparticles are added to cementitious composites by dry mixing with cement or dispersion in water. The challenge associated with it is the uniform dispersion of the nanoparticles in the matrix of the composite. The type of mixer and the mixing pattern affect the fresh and hardened properties of the concrete. This article reviews the effect of dispersion of nano particles, type of mixer and mixing pattern on the properties of cementitious composites.
We prove that chaotic flows (i.e. flows that satisfy the shadowing property and have a dense subset of periodic orbits) satisfy a reparametrized gluing orbit property similar to the one introduced in ...Bomfim and Varandas (2015). In particular, these are strongly transitive in balls of uniform radius. We also prove that the shadowing property for a flow and a generic time-t map, and having a dense subset of periodic orbits hold for a C0-Baire generic subset of Lipschitz vector fields, that generate continuous flows. Similar results also hold for C0-generic homeomorphisms and, in particular, we deduce that chain recurrent classes of C0-generic homeomorphisms have the gluing orbit property.
The steel cord conveyor belt surface is prone to damage in mining. The worn belt surface has acceleration characteristics, so timely and rapid repair is very necessary. To quickly and automatically ...repair the worn belt surface is a core design objective of the gluing robot (GR). Based on this objective, a new variant Traveling Salesman Problem (TSP) is put forward: after the worn segments are divided according to the worn information and GR's workspace, path optimization of the gluing robot (POGR) problem is presented at a certain worn segment; then the POGR is simplified into a "double vertices" TSP problem by Hamilton graph, and the mathematical model is built. An improved genetic algorithm (IGA) is proposed to handle the POGR problem, which is called IGA-POGR. The main benefit of the proposed IGA-POGR is the ability to solve POGR of different scales in different ways. The performance of the IGA-POGR is illustrated on four well-known TSP problems. Numerical results show that IGA-POGR does not give any deviation (0%) from the optimal solution. Compared with discrete particle swarm optimization (DPSO), IGA-POGR has better performance in terms of the solving quality and time consumption when solving four idealized POGR problems.
A
bstract
We apply on-shell methods to the bottom-up construction of electroweak amplitudes, allowing for both renormalizable and non-renormalizable interactions. We use the little-group covariant ...massive-spinor formalism, and flesh out some of its details along the way. Thanks to the compact form of the resulting amplitudes, many of their properties, and in particular the constraints of perturbative unitarity, are easily seen in this formalism. Our approach is purely bottom-up, assuming just the standard-model electroweak spectrum as well as the conservation of electric charge and fermion number. The most general massive three-point amplitudes consistent with these symmetries are derived and studied in detail, as the primary building blocks for the construction of scattering amplitudes. We employ a simple argument, based on tree-level unitarity of four-point amplitudes, to identify the three-point amplitudes that are non-renormalizable at tree level. This bottom-up analysis remarkably reproduces many low-energy relations implied by electroweak symmetry through the standard-model Higgs mechanism and beyond it. We then discuss four-point amplitudes. The gluing of three-point amplitudes into four-point amplitudes in the massive spinor helicity formalism is clarified. As an example, we work out the
ψ
c
ψ Zh
amplitude, including also the non-factorizable part. The latter is an all-order expression in the effective-field-theory expansion. Further constraints on the couplings are obtained by requiring perturbative unitarity. In the
ψ
c
ψ Zh
example, one for instance obtains the renormalizable-level relations between vector and fermion masses and gauge and Yukawa couplings. We supplement our bottom-up derivations with a matching of three- and fourpoint amplitude coefficients onto the standard-model effective field theory (SMEFT) in the broken electroweak phase. This establishes the correspondence with the usual Lagrangian approach and paves the way for SMEFT computations in the on-shell formalism.
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