arXiv subjects

Evgeny Kuznetsov

Publications and source records attributed to Evgeny Kuznetsov.

12 recordsLinked to original sources

arXiv2026

The Algebra of compact-open subsets in the spectrum of the ring $C(T)$ for an infinite compact Hausdorff space $T$

For a commutative Bezout ring R, we give a criterion, in terms of colon ideals with principal radical, for the lattice $\mathring{\mathcal{K}}(\mathrm{Spec}(R))$ of compact open subsets of $\mathrm{Spec}(R)$ to be a Heyting algebra. Bezhanishvili and Tressl showed that $\mathring{\mathcal{K}}(\mathrm{Spec}(C(T)))$ is pseudocomplemented whenever T is a basically disconnected compact Hausdorff space, and asked whether $\mathrm{Spec}(C(\beta\mathbb{N}))$ is actually an Esakia space. We show it is not: applying our criterion to $C(\beta\mathbb{N}) \cong \ell^\infty(\mathbb{N},\mathbb{R})$ produces a diagonal counterexample, and the same obstruction rules out $\beta D$ for every infinite discrete D. A grid-existence theorem for $\sigma$-complete Boolean algebras lets us push the construction to every basically disconnected compact Hausdorff space, settling the Bezhanishvili-Tressl question completely: for no infinite compact Hausdorff space T is $\mathrm{Spec}(C(T))$ an Esakia space.

math.GN↗

arXiv2026

The Solar Neutrino and Astro-Particle PhYsics (SNAPPY) CubeSat Development

The SNAPPY CubeSat, which was launched May 3, 2026, will demonstrate and space qualify the nuSol neutrino-detection technology. The nuSol technology detects solar neutrinos using a gallium isotope which decays by emitting two particles spaced apart in time; this allows differentiating neutrino events from cosmic rays. In the NIAC Phase II project review in 2021, concept and science were determined to be feasible; however, two precursor studies were recommended before pursuing a full mission study. These studies were to characterize the true deep-space background for the detector's gallium double-pulse signal and to collect a statistically significant number of double-pulse events demonstrating that fast electronics can reliably select and analyze this signal. To test double-pulse signals in space, a NIAC Phase III funded building a 3U CubeSat carrying a 0.1-kg gallium-aluminum-gadolinium-garnet detector housed within an active veto array and shielding. Because the detector requires deep-space-like conditions, the CubeSat is designed for a polar low-Earth orbit at 450 km or higher altitude, collecting data over the Earth's poles above the Van Allen belts. The detector is highly sensitive, with roughly 7-percent energy resolution, with active veto shielding and passive shielding using a patented tungsten-powder and epoxy mixture that disintegrates upon atmospheric reentry. SNAPPY enables additional science during the extended mission phase of year two operations. These include measurements of solar wind particle density and energy spectra with particle identification of electrons, protons, and alpha particles; detection of very low-energy gamma rays from galactic gamma-ray bursts without directionality.

physics.ins-det↗

arXiv2026

Two stages of magnetic filament formation in the solar convective zone

This paper presents a brief overview of studies of magnetic filament formation in the solar convection zone. Two stages of magnetic filament formation and development are distinguished. The first stage can be described within the kinematic approximation for the MHD equation, since the average kinetic energy of convective motion exceeds the average magnetic field energy. Moreover, magnetic Reynolds number is on the order of $10^6$. Therefore, at the initial stage of magnetic filament formation, the magnetic field can be considered frozen-in. It turns out that at this stage, magnetic filaments begin to form at the boundaries of convective cells in hyperbolic regions of the flow. These regions act as attractors for the magnetic field. At the free boundary of the convective zone near the interfaces between convective cells, the magnetic field has a predominantly normal component relative to the boundary. As the magnetic field increases, the field's frozen-in nature in the filament is disrupted, and saturation occurs due to finite conductivity. It is important to note that the magnetic field growth and saturation in the filament at this stage can be determined by analyzing the behavior of the magnetic field at the free boundary, which, according to observations, can be considered flat. Moreover, the formation of magnetic filaments is independent of the internal structure of the convective cells and is determined by the behavior of the convective flow along the free surface. In the next stage, when the magnetic field in the filament is sufficiently strong, the magnetic field pressure gradient begins to impede the convective flow, leading to a shift of the hyperbolic regions toward the convective flow along the free surface. As a result, the transverse size of the filament increases and stops when the kinetic energy density and the magnetic field energy density become comparable.

astro-ph.SR↗

arXiv2025

The Extreme Universe Observatory on a Super-Pressure Balloon II: Mission, Payload, and Flight

The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2) is a pathfinder mission toward a space-based observatory such as the Probe of Extreme Multi-Messenger Astrophysics (POEMMA). The aim of POEMMA is the observation of Ultra High Energy COsmic Rays (UHECRs) in order to elucidate their nature and origins and to discover $\gtrsim$ 20 PeV very high energy neutrinos that originate from transient and steady astrophysical sources. EUSO-SPB2 was launched from W\=anaka New Zealand on May 13th, 2023 as a NASA Balloon Program Office test flight. The mission goals included making the first near-space altitude observations of the fluorescence emission from UHECR-induced extensive air showers (EASs) and making the first direct Cherenkov light emission from PeV cosmic rays traversing Earth's atmosphere. In addition, a Target of Opportunity program was developed for selecting and scheduling observations of potential neutrino sources as they passed just below the Earth's limb. Although a leaky balloon forced termination over the Pacific Ocean after 37 hours, data was collected to demonstrate the successful commissioning and operation of the instruments. This paper includes a description of the payload and the key instruments, pre-flight instrument characterizations in the lab and in the desert, flight operations and examples of the data collected. The flight was too short to catch a UHECR event via fluorescence, however about 10 candidate EAS events from cosmic rays were recorded via Cherenkov light.

astro-ph.HE↗

arXiv2025

Commissioning and Performance of the Trinity Demonstrator

The Trinity Demonstrator is a proof of concept prototype for the Trinity Neutrino Observatory, which is sensitive to astrophysical neutrinos above PeV energies. The Demonstrator is a one-square meter class imaging atmospheric Cherenkov telescope deployed on Frisco Peak, Utah, and remotely operated. The light-collection surface is equipped with 77 mirror facets with 15 cm diameter, and its $3.87^\circ\times3.87^\circ$ field of view is instrumented with a 256-pixel camera yielding a $0.24^\circ$ angular resolution. The camera signals are digitized with a 100 MS/s, and 12-bit resolution switched capacitor array readout. We discuss the Demonstrator's design, the telescope's deployment on Frisco Peak, and its commissioning.

astro-ph.IM↗

arXiv2024

The EUSO-SPB2 Fluorescence Telescope for the Detection of Ultra-High Energy Cosmic Rays

The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2) flew on May 13$^{\text{th}}$ and 14$^{\text{th}}$ of 2023. Consisting of two novel optical telescopes, the payload utilized next-generation instrumentation for the observations of extensive air showers from near space. One instrument, the fluorescence telescope (FT) searched for Ultra-High Energy Cosmic Rays (UHECRs) by recording the atmosphere below the balloon in the near-UV with a 1~$μ$s time resolution using 108 multi-anode photomultiplier tubes with a total of 6,912 channels. Validated by pre-flight measurements during a field campaign, the energy threshold was estimated around 2~EeV with an expected event rate of approximately 1 event per 10 hours of observation. Based on the limited time afloat, the expected number of UHECR observations throughout the flight is between 0 and 2. Consistent with this expectation, no UHECR candidate events have been found. The majority of events appear to be detector artifacts that were not rejected properly due to a shortened commissioning phase. Despite the earlier-than-expected termination of the flight, data were recorded which provide insights into the detectors stability in the near-space environment as well as the diffuse ultraviolet emissivity of the atmosphere, both of which are impactful to future experiments.

astro-ph.IM↗

arXiv2024

The Camera and Readout for the Trinity Demonstrator and the EUSO-SPB2 Cherenkov Telescope

We developed a modular silicon photomultiplier camera to detect Earth-skimming PeV to EeV tau neutrinos with the imaging atmospheric Cherenkov technique. We built two cameras, a 256-pixel camera with S14161-6050HS SiPMs for the Trinity Demonstrator located on Frisco Peak, Utah, and a 512-pixel camera with S14521-6050AN SiPMs for the EUSO-SPB2 Cherenkov Telescope. The front-end electronics are based on the eMUSIC ASIC, and the camera signals are sampled and digitized with the 100MS/s and 12-bit AGET system. Both cameras are liquid-cooled. We detail the camera concept and the results from characterizing the SiPMs, bench testing, and calibrating the two cameras.

astro-ph.IM↗

arXiv2024

An explicit Kuznetsov-Muravitsky enrichment

An embedding of arbitrary Heyting algebra H into a reduct from the variety of Kuznetsov-Muravitsky algebras is constructed. An algebraic proof is given that this reduct belongs to the variety of Heyting algebras generated by H.

math.LO↗

arXiv2024

Gamma Ray Detection Efficiency of GAGG Crystal Scintillator Using Three Tagged Gamma Ray Techniques

A CubeSat with a prototype scintillating detector with a sensitive volume of GAGG crystal is being developed with a possible launch date of 2025. Its purpose is to characterize the background signals that mimic the neutrino interaction that the nuSOL (Neutrino Solar Orbiting Laboratory) team is looking for. An important part of the characterization of the backgrounds and the expected real signal is understanding the gamma ray detection efficiency of the prototype detector when compared to simulations performed in Geant4. To this end we have used three techniques to do a measurement of the gamma ray efficiency compared to simulation. The first is using electron capture sources that emit an X-ray before prompt emission of a de-excitation gamma ray, specifically Zn-65 and Mn-54. The second is using a beta + decay source wherein a positron annihilates on an atomic shell electron producing two back-to-back 511 keV gammas followed promptly by a de-excitation gamma, specifically Na-22. The third is using a gamma cascade of two near-simultaneous de-excitation gammas from the same nucleus, specifically from Co-60 decay.

physics.ins-det↗

arXiv2023

EUSO-SPB2 Fluorescence Telescope Calibration and Field Tests

The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2), successfully launched from Wanaka, New Zealand on May 13, 2022, is a precursor for a space-based astroparticle observatory such as the Probe Of Extreme Multi-Messenger Astrophysics (POEMMA). EUSO-SPB2 flew two custom telescopes. Both have UV/UV-visible sensitivity and feature Schmidt optics. The Fluorescence Telescope (FT) measures ultra-high energy cosmic rays by looking down. The Čerenkov Telescope (CT) searches for neutrino signatures by looking toward Earth's limb. The two telescopes each have a 1 m diameter entrance pupil and segmented glass mirrors that collect light from extensive air showers at the PeV and EeV-scale. Here we describe the FT telescope optics together with the results of the FT field tests at the Utah Telescope Array (TA) site from August/September 2022. The FT recorded the night sky background, lasers, and artificial point sources. The field tests included an absolute photometric calibration of the FT telescope that is compared to a piece-wise laboratory calibration.

astro-ph.IM↗

arXiv2018

Modal logic of planar polygons

We study the modal logic of the closure algebra $P_2$, generated by the set of all polygons in the Euclidean plane $\mathbb{R}^2$. We show that this logic is finitely axiomatizable, is complete with respect to the class of frames we call "crown" frames, is not first order definable, does not have the Craig interpolation property, and its validity problem is PSPACE-complete.

math.LO↗

arXiv2017

White paper on EUSO-SPB2

EUSO-SPB2 is a second generation Extreme Universe Space Observatory (EUSO) on a Super-Pressure Balloon (SPB). This document describes the physics capabilities, the proposed technical design of the instruments, and the simulation and analysis software.

astro-ph.HE↗