Geometry - Science topic

We are pleased to invite you to the International Symposium on Differential Geometry and Applications (ISDIGA 2025), organized by Munzur University, which will be held online on July 3-4, 2025. The symposium will cover, but not limited, various topics in differential geometry; including Riemannian and sub-Riemannian geometry, geometric structures...

This book attempts to present a comprehensive survey of the geometry of CR-submanifolds. The theory of submanifolds is one of the most interesting topics in differential geometry. The topic is introduced by Aurel Bejancu as a generalization of holomorphic and totally real submanifolds of almost Hermitian manifolds, in 1978. Afterward, the study of...

This paper presents a closure to “Effect of Footing Geometry and Embedment on the Bearing Capacity and Collapse Mechanism of Shallow Foundations in Sand” by Rameez A. Raja, Venkata A. Sakleshpur, Monica Prezzi, and Rodrigo Salgado. https://doi.org/10.1061/JGGEFK.GTENG-11802.

This workshop investigates the interactions between Euclid’s Elements and practical mathematics in early modern Europe. It focuses on how Euclidean propositions, concepts, and styles were appropriated, adapted, and transformed in practical mathematical treatises aimed at artisans, surveyors, and other non-academic audiences, as well as how the Elem...

Accurate three-dimensional (3D) localization and sensing of intravital fluorescent probes are indispensable for elucidating neural circuit mechanisms and evaluating tumor dynamics. Fluorescence diffusion tomography in reflection geometry (rFDT) offers a powerful tool for circumventing object size limitations and enables volumetric functional imagin...

We derive the spatial curvature term in the Friedmann–Lemaître–Robertson–Walker (FLRW) cosmological model from a first-principles entropic framework that incorporates a universal suppression law for coherence decay. By modifying Jacobson’s thermodynamic derivation of Einstein’s equations to include energy-dependent suppression of gravitational cou...

Η γεωμετρία αποτελεί ένα κεντρικό κομμάτι της μαθησιακής εμπειρίας στην εκπαιδευτική διαδικασία, καθώς παρέχει την ευκαιρία στους μαθητές να αναπτύξουν την ικανότητά τους να αναλύουν, να σκέφτονται και να λύνουν προβλήματα μέσω γεωμετρικών σχημάτων και συσχετίσεων. Μία σημαντική έννοια της γεωμετρίας που αποτελεί τον πυρήνα της παρούσας εργασίας εί...

This is a self-contained research manuscript currently under editorial review for publication. This paper is an attempt to understand how the spectrum of the Laplace-Beltrami operator behaves on a family of expanding Riemannian manifolds, specifically those where the metric is rescaled over time by a growing scale factor. Most results in spectral...

We propose our account of the meaning of local symmetries. We argue that the general covariance principle and gauge principle both are principles of democratic epistemic access to the law of physics, leading to ontological insights about the objective nature of spacetime. We further argue that relationality is a core notion of general-relativistic...

This quantitative experimental study aims to examine the effect of mathematical representation ability and mathematical spatial ability on students’ mathematics learning outcomes, with gender as a moderating factor. The population consisted of 74 third-semester Mathematics Education students at UIN Syekh Nurjati Cirebon during the 2024/2025 academi...

Let k be a nontrivial finite-dimensional Lie algebra of vector fields on a manifold M, and consider the family of Lorentzian metrics on M whose Killing algebra contains k. We show that scalar relative differential invariants of such metrics, with respect to a Lie algebra of vector fields on M preserving k, can be used to detect the horizons of seve...

We study the geometry of Fatou components in non-Archimedean dynamics. By explicitly computing a wandering domain constructed by Benedetto, we provide the first example of a Fatou component that is an irrational disk.

In this study, we introduce and investigate a new 3D flow-field geometry for proton exchange membrane water electrolyzers (PEMWEs) called Angular Approach Flowfield (AAF) geometry. The performance of this AAF geometry (V2.0 and V2.1) is compared to the conventional triple-serpentine triple-serpentine (TSHM) geometry through numerical modeling and i...

Earlier work of the first author [15] examined two boundary value problems associated to the Gauss Curvature Flow on a surface of revolution generated by a positive, differentiable function on a compact interval. In this continuation, a noncompact problem is addressed.

This paper investigates the inverse biharmonic scattering problems of identifying the shape and location of the obstacle with phased and phaseless measurement data. A direct imaging method based on reverse time migration is proposed for reconstructing the extended obstacle with one of four types of boundary conditions on the obstacle. The newly dev...

In this study, a variable cosmological constant model is created for anisotropic star structures, which satisfies the remaining physical requirements, and validates the required energy conditions (Ecs), and TOV equations. First, the Finch-Skea spacetime solution is taken into account as a static spherically symmetric metric. Moreover, external Schw...

This manuscript presents an approach for simultaneously optimizing the connectivity and elevation of grid-shell structures acting in pure compression (or pure tension) under the combined effects of a prescribed external loading and the design-dependent self-weight of the structure itself. The method derived herein involves solving a second-order co...

We show that the Eulerian tonnetz, which associates three minor chords to each major chord and three major chords to each minor chord, can be represented by a bipartite graph with twelve white vertices signifying major chords and twelve black vertices signifying minor chords. This so-called Levi graph uniquely determines the combinatorial geometry...

In this paper, we introduce a new spherical coordinate transformation, which transforms three-dimensional curved geometries into a unit sphere. This transformation plays an important role in spectral approximations of differential equations in three-dimensional curved geometries. Some basic properties of the spherical coordinate transformation are...

In this article, we establish various geometric properties for bounded double sequences of bi-complex numbers, regular double sequences of bi-complex num- bers, regular null double sequences of bi-complex num- bers, convergent double sequences of bi-complex numbers in Pringsheim sense, null double sequences of bi-complex numbers in Pringsheim sense...

We study the double cone geometry proposed by Saad, Shenker, and Stanford in de Sitter space. We demonstrate that with the inclusion of static patch observers, the double cone leads to a linear ramp consistent with random matrix behavior. This ramp arises from the relative time shift between two clocks located in opposite static patches.

Ende 2020 wurde das Forschungsprojekt IGF 19693 BR an der TU Ilmenau in Zusammenarbeit mit dem Verband der deutschen Federnindustrie e. V. (VDFI) mit dem Titel "Erneuerung der Dauerfestigkeitsschaubilder für kaltgeformte Schraubendruckfedern in DIN EN 13906-1 mit methodisch rechnerischer Herangehensweise" abgeschlossen. Darin wurden Dauerfestigkeit...

The category of affine schemes is a tangent category whose tangent bundle functor is induced by K\"ahler differentials, providing a direct link between algebraic geometry and tangent category theory. Moreover, this tangent bundle functor is represented by the ring of dual numbers. How special is this tangent structure? Is there any other (non-trivi...

We present a unifying perspective in which the global regularity of the three-dimensional incompressible Navier–Stokes equations emerges naturally from a universal entropic suppression mechanism governed by a 1⁄E² decay law. Building on a recently completed proof of global existence and smoothness for initial data in Hˢ(ℝ³), with s > 5⁄2, we reint...

This paper proposes a set of gravitational laws derived from Desmos theory, where gravity emerges from motion and rotational dynamics rather than mass alone. By examining empirical data from planetary and lunar orbits, the paper confirms the existence of a universal dimensionless ratio governing gravitational equilibrium. The results explain the pr...

The Kibble-Zurek scaling reveals the universal dynamics when a system is linearly ramped across a symmetry-breaking phase transition. However, in reality, inevitable finite-size effects or symmetrybreaking perturbations can often smear out the critical point and render the phase transition into a smooth crossover. In this letter, we show experiment...

Fixing a constant $\lambda>0$, for any parameter $\varepsilon>0$ we study critical points of the Yang--Mills--Higgs energy \[ \mathcal{Y}_{\varepsilon}(\nabla,\Phi) = \int_M \varepsilon^2|F_{\nabla}|^2 + |\nabla\Phi|^2 + \frac{\lambda}{4\varepsilon^2}(1-|\Phi|^2)^2, \] defined for pairs $(\nabla,\Phi)$, where $\nabla$ is a connection on an $SU(2)$-...

We correct the description of p-closed foliations on bi-disc quotients in McQuillan (Eur J Math 3(3):433–470, 2017) occasioned by the omission of modèles étranges. As such, the geometry of curves remains exactly that of op. cit., but its relationship with the arithmetic is richer.

This paper presents a conceptual and efficient geometric framework to encode the algebraic structures on the category of superselection sectors of an algebraic quantum field theory on the $n$-dimensional lattice $\mathbb{Z}^n$. It is shown that, under certain assumptions which are implied by Haag duality, the monoidal $C^\ast$-categories of localiz...

In a previous study we investigated the spherically symmetric Schwarzschild and Schwarzschild-de Sitter solutions within a Finsler-Randers-type geometry. In this work we extend our analysis to charged and rotating solutions, focusing on the Reissner-Nordstr\"om and Kerr-like metrics in the Finsler-Randers gravitational framework. In particular, we...

O ensino de Geometria tem se transformado com o avanço das tecnologias digitais, tornando-se mais dinâmico e interativo. O objetivo deste artigo é analisar como essas tecnologias vêm sendo integradas à Educação Básica brasileira, destacando o uso de recursos que favorecem a aprendizagem. A pesquisa, fundamentada em uma revisão bibliográfica de prod...

This letter proposes a design of low peak-to-average power ratio (PAPR), low symbol error rate (SER), and high data rate signal for asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) systems. The proposed design leverages a variational autoencoder (VAE) incorporating gradual loss learning to jointly optimize the ge...

In this paper, we obtain a formula for time in general relativity from solutions of the Einstein-Hamilton-Jacobi equation along paths of steepest descent in the configuration space of general relativity. The formula for time emerges from the geometry of configuration space via the length of the steepest descent paths which is measured with respect...

Higher-order exceptional points (EPs) in non-Hermitian systems showcase diverse physical phenomena but require more parameter space freedom or symmetries. It leads to a challenge for the exploration of high-order EP geometries in low-dimensional systems. Here we observe both a third-order exceptional surface and line in a Jaynes-Cummings triangle c...

Rydberg tweezer arrays provide a platform for realizing spin-1/2 Hamiltonians with long-range tunnelings decaying according to power-law with the distance. We numerically investigate the effects of positional disorder and dimerization on the properties of excited states in such a one-dimensional system. Our model allows for the continuous tuning of...

Esta investigación partió de una problemática relacionada con las dificultades que presentan los estudiantes en la comprensión de conceptos geométricos y trigonométricos. El presente estudio tuvo como objetivo fortalecer el uso de la plataforma GeoGebra Classroom en los docentes, para mejorar la comprensión y aplicación de los conceptos geométricos...

In tomography, range conditions or data consistency conditions (DCCs) on functions have proven useful for geometric self-calibration, which involves identifying geometric parameters of acquisition systems based only on acquired radiographic images. These self-calibration methods using range conditions on functions typically require non-truncated da...

This paper proposes a set of gravitational laws derived from Desmos theory, where gravity emerges from motion and rotational dynamics rather than mass alone. By examining empirical data from planetary and lunar orbits, the paper confirms the existence of a universal dimensionless ratio governing gravitational equilibrium. The results explain the pr...

We evaluate the loss of stability of axially compressed slender and thick-walled tubes subject to a residual stress distribution. The nonlinear theory of elasticity, when used to analyze the underlying deformation, shows that the residual stress induces preferred directions in the reference configuration. The incremental theory, given in Stroh form...

We propose a theoretical framework unifying principles of relativistic spacetime with the nonlocal correlations characteristic of quantum entanglement-a regime we term Entangled Relativity. Drawing on recent advancements in quantum field theory in curved spacetime, the holographic principle, and relativistic quantum information, this study investig...

🖼️ Quote: "Spacetime may not be smooth—it may be symbolically structured and seasonally alive." - The figure illustrates GRB 221009A's alignment with Earth's symbolic coherence distortion profile, reinforcing the idea that timing delays can emerge from structured ∞-tensor geometry rather than broken Lorentz invariance.

The Article Abstract is not available

Based on one year experiment on silty clay loam soil of Madhya Pradesh, it is concluded that the whole seed tubers are significantly superior as compared to cut seed pieces in growth as well as yield attributes.

The quasi-redirecting (QR) boundary, introduced by Qing and Rafi, generalizes the Gromov boundary for studying the large-scale geometry of finitely generated groups. Although it is not known to exist for all such groups, its existence has been established for several important classes. We prove that if a finitely generated group G has linear diverg...

In this paper, we propose a method for transferring feature representation to lightweight student models from larger teacher models. We mathematically define a new notion called \textit{perception coherence}. Based on this notion, we propose a loss function, which takes into account the dissimilarities between data points in feature space through t...

Theory of electromagnetic field, specified by an effective action functional, is considered. The causality condition is imposed in the form of a requirement that the group velocities of propagation of small and soft disturbances over the background of an external constant field should not exceed the speed of light in vacuum. It is shown that these...

We provide a C ⁰ counterexample to the Lagrangian Arnold conjecture in the cotangent bundle of a closed manifold. Additionally, we prove a quantitative h -principle for subcritical isotropic embeddings in contact manifolds and provide an explicit construction of a contact homeomorphism that takes a subcritical isotropic curve to a transverse one. O...

We study the geometry of compact strong HKT and, more generally, compact BHE manifolds. We prove that any compact BHE manifold with full holonomy must be K\"ahler and we establish a similar result for strong HKT manifolds. Additionally, we demonstrate a rigidity theorem for strong HKT structures on solvmanifolds and we completely classify those wit...

We study the apparent optical brightness of satellite streaks in ground-based observatory cameras as the orbit height is varied. This is done via simulations. Several factors are in play: the range to the satellite, satellite size and geometry, the diameter of the telescope aperture, and the angular velocity of the satellite image as it streaks acr...

This paper establishes a connection between the Hawking temperature of spacetime horizons and global topological invariants, specifically the Euler characteristic of Wick-rotated Euclidean spacetimes. This is demonstrated for both de Sitter and Schwarzschild, where the compactification of the near-horizon geometry allows for a direct application of...

A bstract We construct a plethora of type-II supergravity solutions featuring AdS factors in their geometries, derived from integrable deformations of coset CFTs. Specifically, we uplift the λ -deformed models of SO(4) k / SO(3) k and SO(5) k / SO(4) k , including the non-compact version of the latter. Requiring reality for the backgrounds imposes...

Modern 3D reconstruction and novel view synthesis approaches have demonstrated strong performance on scenes with opaque Lambertian objects. However, most assume straight light paths and therefore cannot properly handle refractive and reflective materials. Moreover, datasets specialized for these effects are limited, stymieing efforts to evaluate pe...

The moment-SOS (sum of squares) hierarchy is a powerful approach for solving approximately and globally non-convex polynomial optimization problems (POPs) at the price of solving a family of convex semidefinite optimization problems (called moment-SOS relaxations) of increasing size, controlled by an integer, the relaxation order. We say that a rel...

Standards quality irradiance meters have been developed at the National Institute of Standards and Technology (NIST) to realize a detector based spectral irradiance scale. The design criteria and the optical and radiometric characterization of diffuser-input irradiance meters are discussed. The input geometry optimization is described for a broad-b...

This paper presents a design of a dual-polarized metasurface reflecting surface that reflects TE and TM polarized waves at two different angles. The reflection angles are controlled by modulating the surface impedance on the reflecting surface. This modulated-surface-impedance reflecting surface is implemented by periodic super cells metasurfaces....

For smooth optimization problems with a Hermitian positive semidefinite fixed-rank constraint, we consider three existing approaches including the simple Burer–Monteiro method, and Riemannian optimization over quotient geometry and the embedded geometry. These three methods can be all represented via quotient geometry with three Riemannian metrics...

Neutrinos are excellent probes of the inner structures of supernovas. However, an understanding of their dynamics remains incomplete, which is crucial for properly interpreting the detector data. The huge matter density inside a core collapse supernova affects the self-coupling of the neutrinos through a geometrical four-fermion interaction induced...

We study holographic subregion complexity in a moving strongly coupled plasma in dimensions d = 2 , 3, 4, which is holographically dual to a boosted black brane metric in a higher dimensional geometry. The proposal we employ is the one that identifies the complexity of a mixed state by the volume of codimensional-one hypersurface enclosed by Hubeny...

Zonotopal algebras, introduced by Postnikov--Shapiro--Shapiro, Ardila--Postnikov, and Holtz--Ron, show up in many different contexts, including approximation theory, representation theory, Donaldson--Thomas theory, and hypertoric geometry. In the first half of this paper, we construct a perfect pairing between the internal zonotopal algebra of a li...

Spațiu Ca natură non dialectică a dicţionarului clasic "spațiu" este, "SPÁȚIU, spații, s. n. 1. (Fil.; la sg.) Formă obiectivă și universală a existenței materiei, inseparabilă de materie, care are aspectul unui întreg neîntrerupt cu trei dimensiuni și exprimă ordinea coexistenței obiectelor lumii reale, poziția, distanța, mărimea, forma, întindere...

This study investigates the influence of back pressure on the mass ejection coefficient (u) of low-pressure methane-air ejectors through a combined approach of one-dimensional mathematical modeling and computational fluid dynamics (CFD) simulations. By establishing a quadratic relationship between u and back pressure (hc), we reveal three distinct...

In this study, we present the notion of 2-conformal vector fields on Riemannian and semi-Riemannian manifolds, which are an extension of Killing and conformal vector fields. Next, we provide suitable vector fields in Sol space that are 2-conformal. A few implications of 2-conformal vector fields in hyperbolic Ricci solitons are investigated. In add...

This paper explores the geometry of 3-dimensional quasi Sasakian manifolds under CL-transformations. We construct both infinitesimal and CL-transformation and demonstrate that the former does not necessarily yield projective killing vector fields. A novel invariant tensor, termed the CL-curvature tensor, is introduced and shown to remain invariant...

Electron systems with multiple redox-active units have attracted attention in various fields due to their potential applications. However, the design strategy remains elusive to selectively synthesize the diverse molecular structures of redox-convertible species. In this study, covalently linked quinodimethane derivatives with a sulfur bridge [(Ar4...

Este estudo tem por objetivo analisar artigos científicos publicados em periódicos internacionais de língua inglesa, entre 2010 e 2020, sobre o sentido espacial infantil na educação matemática. Por meio de uma revisão sistemática integrativa, analisa-se 185 artigos utilizando a Análise de Redes Sociais (SNA). Os resultados mostram um crescimento si...

In this paper, we propose a channel acquisition approach with time-frequency phase-shifted pilots (TFPSPs) for massive multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) systems. We first present a triple-beam (TB) based channel tensor model, allowing for the representation of the space-frequency-time (SFT) domain chann...

Penelitian tindakan kelas ini bertujuan meningkatkan kemampuan mencocokkan bentuk anak usia 5-6 tahun di KB Tunas Harapan Darmo menggunakan Puzzle Shape Memory Game. Dilaksanakan dalam dua siklus (model Kemmis & McTaggart) dengan 16 subjek, data dikumpulkan melalui observasi dan dokumentasi. Hasil awal menunjukkan kemampuan geometri terbatas (39,68...

We propose a microcylinder as a highly dispersive and compact delay line. The cylindrical geometry implies a large anomalous dispersion of group velocities for the whispering gallery modes circulating at the surface of the cylinder. We demonstrate the device effectiveness in spectral measurements using the dispersive Fourier transformation approach...

The Feynman path integral implicitly employs a uniform, flat measure across all trajectories. Building on entropy geometry and the principle of distinguishability introduced in the preceding letters, the Total Entropic Quantity (TEQ) framework replaces this flatness with curvature shaped by entropy flow. This letter clarifies the geometric meaning...

This paper presents an innovative methodology to determine the formability limits of thin-walled tubes with square cross-sections and L-section profiles. These geometries are studied for the first time in this context, providing a pioneering insight into their fracture behaviour. The methodology considered utilizes digital image correlation (DIC) a...

Chynoweth and Sewell developed the semigeostrophic equations as a mathematical model for an atmospheric front based on the singularities of the Legendre transformation between different pairs of dual variables. Drawing inspiration from their work, we formalize the idea of a Chynoweth–Sewell front and illuminate its geometrical meaning from the view...

Material processing induces texture development which in turn results in anisotropy in the macroscopic plastic properties. Improvement of the finite-element predictions of the geometry of the final part (e.g. shape, thickness reduction) necessitates accurate modelling of the plastic anisotropy. In this paper, we show that a polycrystalline model fo...

We study the geometry of Riemannian metrics without conjugate points on manifolds which are diffeomorphic to \(M = \Sigma \times S^1\), where \(\Sigma\) is a compact orientable surface of genus \(g \geq 2\). This addresses a question related to the generalized Hopf conjecture: whether such metrics must necessarily exhibit a product structure on the...

A new adhesive strength evaluation method is explained based on the intensity of singular stress field (ISSF) considering three-dimensional adhesive geometries.

Modular Berry transport associates a geometric phase to a zero mode ambiguity in a family of modular operators. In holographic settings, this phase was shown to encode nontrivial information about the emergent spacetime geometry. We reformulate modular Berry transport for arbitrary von Neumann algebras, including giving a precise definition of the...

We propose a simple definition of a Born geometry in the framework of Künneth geometry. While superficially different, this new definition is equivalent to the known definitions in terms of para-quaternionic or generalized geometries. We discuss integrability of Born structures and their associated connections. In particular we find that for integr...

This paper discusses the influence of joint orientation with non-rotationally symmetric geometry, on load distribution and structural behavior. The focus is on understanding how changes in the alignment of individual joints affect the distribution of load, neighboring joints, and the overall performance of the component. Lap shear specimens with mu...

Background/Objectives: Preventing head deformity in the early postnatal period could avert positional plagiocephaly (PP). Accordingly, we developed a novel prophylactic device to prevent head deformity and examined its impact on the incidence of PP and prevention of severe PP at 3 months of age. Methods: The newly developed prophylactic device was...

In large language model (LLM) pretraining, data quality is believed to determine model quality. In this paper, we re-examine the notion of "quality" from the perspective of pre- and post-training co-design. Specifically, we explore the possibility that pre-training on more toxic data can lead to better control in post-training, ultimately decreasin...

Mid‐infrared (MIR; 5–35 μm) spectroscopy is often used for mineralogical identification on planetary surfaces. Laboratory spectra aiding remote sensing observations are typically performed in reflection geometries, while MIR spectra of planetary surfaces are typically obtained via emission. Here we explore the validity of Kirchhoff's Law in convert...

Macroscopic modeling of a non-crimp fabric’s (NCF’s) forming behavior is challenging as it strongly depends on the textile architecture, fiber type, and stitching type. While shear is the main deformation mode of woven fabrics, membrane modeling approaches for NCFs should also consider stitching deformation and roving slippage. However, for 0°/90°...

Single Point Incremental Forming (SPIF) has been developed as a versatile technique for manufacturing complex sheet metal components without requiring custom dies. This study investigates the influence of tool geometry and tool material on the forming depth, forming force and form-accuracy of parts fabricated with Al6061. Square base pyramid shape...

Statistical manifolds, the parameter spaces of smooth families of probability density functions, are the central objects of study in information geometry. While the elementary differential geometry of Riemannian statistical manifolds is well-known, their conformal geometry remains entirely unexplored. In this article, we begin this programme of exp...

The collective ground state for a spherical symmetric dust ball has been investigated recently in R. Casadio [Phys. Lett. B 843 (2023) 138055]. In this study, we refine that model by obtaining a mass distribution that accounts for the superposition of wave functions across different layers. The refined mass distribution shows significant deviations...

The problem considered can in general be described as the problem of proving rigorously that as the Reynolds number of a fluid flow tends to infinity, the drag coefficient remains bounded. It has been proven for flows in domains of certain, rather restrictive, set of geometries, but not in general. The drag is the sum of the pressure drag and frict...

The strip drawing test is widely used to assess the friction coefficient in sheet metal forming processes. A significant challenge in these tests is the presence of stress risers at the edges of flat punch configurations with rounded edges, which result in uneven contact pressure distributions and complicate friction characterization. To address th...

This paper focuses on the failure behavior of clinched specimens with various stiffnesses under shear tensile loading. The primary objective is to assess the influence of the specimen stiffness with an arrangement of clinched joints. The specimen stiffness depends on several variables. In addition to the material selection, the specific choice of g...

Manufacturing deep drawing parts, e. g. car bodies, method planning as a step of development is used for designing and harmonising the forming operations. The result of method planning is a process which is as stable as possible to produce a part of a fix geometry. The ability to vary the drawing depth can be an advantage to develop a great number...

This letter introduces the concept of entropy geometry as a structural principle governing resolution and motion. Rather than assuming a preexisting spacetime background, we propose that distinguishability between configurations defines a curved manifold-an entropy geometry-whose gradient determines how systems evolve, and whose curvature constrain...

We study linearizability of actions of finite groups on cubic threefolds with non-isolated singularities.

Se estudia la caracterización de los procesos subyacentes al razonamiento geométrico que promueven los libros de texto de educación secundaria de Chile. Para ello, se consideran las tareas corres-pondientes al eje temático de geometría. Se realiza un análisis de contenido, utilizando herramientas del enfoque ontosemiótico del conocimiento y la inst...

This paper derives a recursive relationship and closed formula for the number of pieces of dimensional sphere when divided by great spheres in general position. There are two main parts of this paper. The first is the proof of the recursive relationship and closed formula of a possibly known problem: the number of pieces separated by copies of -dim...

In the present paper, the special Viviani’s curve is revisited in the context of Smarandache geometry. Accordingly, the paper first defines the special Smarandache curves of Viviani’s curve, including the Darboux vector. Then, it expresses the resulting Frenet apparatus for each Smarandache curve in terms of the Viviani’s curve. The paper is also s...

The concept of a contact CR-submanifold in a Sasakian manifold (Yano and Kon in Geom Dedicata 10:369-391, 1981) relates deeply to CR geometry, which originated from the study of real hypersurfaces in complex manifolds (Bejancu in Geometry of CR submanifolds. D. Reidel Publishing Company, Dordrecht, 1986). Initially introduced for anti-holomorphic s...

This study introduces a quantum gravitational simulation of black hole (BH) formation and white hole (WH) emergence using an entangled lattice-based qubits formalism. Spacetime is modeled as a crystalline lattice where each site holds a qubit entangled with its neighbors. We reformulate gravitational curvature in terms of quantum entanglement ampli...

In this study, a dual-band dual-beam shared-aperture reflector antenna based on a Cassegrain configuration is designed using a frequency-selective surface (FSS) subreflector. The antenna generates two shaped beams that operate at different frequencies and can spatially overlap. One beam contour can be independently optimized by properly designing t...

In this paper, we present two methods to derive the formula for the volume of n-dimensional spheres in Euclidean space and analyze its asymptotic behavior as n approaches infinity using Stirlings formula. We then establish a connection between the infinite sum of all even-dimensional spheres of radius r and the exponential function through a differ...

Twistor theory was initially developed to describe the geometry of Minkowski spacetime in terms of its null geodesics. The natural generalization to curved spacetimes requires the ubiquitous existence of alpha-planes, this requiring the Weyl curvature to be anti-self-dual, which for a real spacetime implies conformal flatness. A bi-twistor, however...