arXiv subjects

Dmitry Belyaev

Publications and source records attributed to Dmitry Belyaev.

6 recordsLinked to original sources

arXiv2019

Single-step modified electrodes for vitamin C monitoring in sweat

We demonstrate a flexible sensor for ascorbic acid detection in sweat based on single-step modified gold microelectrodes. The modification consists on the electrodeposition of alginate membrane with trapped CuO nanoparticles on top of the electrodes. The electrodes are fabricated at a thin polyimide support and the soft nature of the membrane can withstand mechanical stress far beyond the requirements for skin monitoring. We further show the efficient detection of ascorbic acid at the micromolar levels in both, a neutral buffer and acidic artificial sweat, at ultra-low applied potential (-5 mV). The effect of possible interfering species present in sweat is minimized, with no observable cross-reaction, thus maintaining a high degree of selectivity despite absence of enzymes in the fabrication scheme. This sensor is envisioned as a promising component of a wearable device for e.g. non-invasive monitoring of micronutrient loss through sweat.

physics.app-ph↗

arXiv2012

The $\mathcal {OSP}(2,2|16)$ superconformal theory is free!

The SuperConformal theory in three space-time dimensions with SO(16) $R$-symmetry, 128 bosons, and 128 fermions, cannot sustain interactions. This result is obtained using both light-cone superspace techniques which rely on algebraic consistency, and covariant methods which rely on SO(16) Fierz identities which fail to produce the desired algebra.

hep-th↗

arXiv2010

Link Graph Analysis for Adult Images Classification

In order to protect an image search engine's users from undesirable results adult images' classifier should be built. The information about links from websites to images is employed to create such a classifier. These links are represented as a bipartite website-image graph. Each vertex is equipped with scores of adultness and decentness. The scores for image vertexes are initialized with zero, those for website vertexes are initialized according to a text-based website classifier. An iterative algorithm that propagates scores within a website-image graph is described. The scores obtained are used to classify images by choosing an appropriate threshold. The experiments on Internet-scale data have shown that the algorithm under consideration increases classification recall by 17% in comparison with a simple algorithm which classifies an image as adult if it is connected with at least one adult site (at the same precision level).

cs.IR↗

arXiv2010

The BLG Theory in Light-Cone Superspace

The light-cone superspace version of the d=3, N=8 superconformal theory of Bagger, Lambert and Gustavsson (BLG) is obtained as a solution to constraints imposed by OSp(2,2|8) superalgebra. The Hamiltonian of the theory is shown to be a quadratic form of the dynamical supersymmetry transformation.

hep-th↗

arXiv2003

Twisting Warped Supergravity

We study gauged five-dimensional supergravity on the interval [0,πR]. We find a set of boundary conditions with respect to which the theory is locally supersymmetric. For theories with detuned brane tensions (Λ_4<0), we show that these boundary conditions can be used to spontaneously break global supersymmetry. For the original, tuned Randall-Sundrum scenario (Λ_4=0), we prove that the locally supersymmetric boundary conditions are also globally supersymmetric. We lift the theory from [0,πR] to S^1 and R, with arbitrary twists for the fermions, and cast these results in the language of the Scherk-Schwarz mechanism.

hep-th↗

arXiv2002

Supersymmetric branes with (almost) arbitrary tensions

We present a supersymmetric version of the two-brane Randall-Sundrum scenario, with arbitrary brane tensions T_1 and T_2, subject to the bound |T_{1,2}| \leq \sqrt{-6Λ_5}, where Λ_5 < 0 is the bulk cosmological constant. Dimensional reduction gives N=1, D=4 supergravity, with cosmological constant Λ_4 in the range \halfΛ_5 \leq Λ_4 \leq 0. The case with Λ_4 = 0 requires T_1 = -T_2 = \sqrt{-6Λ_5}. This work unifies and generalizes previous approaches to the supersymmetric Randall-Sundrum scenario. It also shows that the Randall-Sundrum fine-tuning is not a consequence of supersymmetry.

hep-th↗