A5088935664- Geometric Analysis and Curvature Flows
- Geometry and complex manifolds
- Advanced Differential Geometry Research
- Point processes and geometric inequalities
- Geometric and Algebraic Topology
- Nonlinear Partial Differential Equations
- Advanced Numerical Analysis Techniques
- Mathematics and Applications
- Computational Geometry and Mesh Generation
- Mesoporous Materials and Catalysis
- Nonlinear Waves and Solitons
- COVID-19 Clinical Research Studies
- Polymer Foaming and Composites
- Immune responses and vaccinations
- Polynomial and algebraic computation
- SARS-CoV-2 and COVID-19 Research
- Algebraic Geometry and Number Theory
- Advanced Mathematical Modeling in Engineering
- Crystal Structures and Properties
- Analytic and geometric function theory
- Advanced Optimization Algorithms Research
- Optimization and Variational Analysis
- Black Holes and Theoretical Physics
- Glass properties and applications
- Luminescence Properties of Advanced Materials
Universidade Federal do Piauí
2012-2024
Universidade de Fortaleza
2008
The aim of this work is to show that a compact smooth star-shaped hypersurface $\Sigma ^n$ in the Euclidean sphere $\mathbb {S}^{n+1}$ whose second function curvature $S_2$ positive constant must be geodesic {S}^{n}(\rho )$. This generalizes result obtained by Jellett $1853$ for surfaces ^2$ with mean space {R}^3$ as well recent authors type curvature. In order prove our theorem we shall present formula operator $L_{r}(g)=div\left (P_r\nabla g\right )$ associated new support $g$ defined over...
Nanocristais de CaWO4 foram sintetizados pelos métodos coprecipitação com diferentes razões do solvente (água/etilenoglicol) e processados à temperatura ambiente. Estes nanocristais caracterizados por difração raios X, espectroscopia Raman, na região infravermelho transformada Fourier (FT-IR) espectrofotometria absorção ultravioleta-visível. De acordo os padrões espectros dos cristais exibiram apenas a estrutura tetragonal tipo scheelita sem presença fases intermediárias. Os dados obtidos...
The aim of this work is to deal with index closed orientable non-totally geodesic minimal hypersurface Σn the Euclidean unit sphere Sn+1 whose second fundamental form has squared norm bounded from below by n. In case we shall show that stability, denoted IndΣ, greater than or equal n + 3, equality occurring at only Clifford tori $\mathbf{S}^k(\frac{k}{n})\times\mathbf{S}^{n-k}(\sqrt{\frac{(n-k)}{n}})$. Moreover, prove also that, besides tori, have following gap: IndΣ ≥ 2n 5.
In a remarkable work~\cite{wei11}, G. Wei established estimates for the eigenvalues of Laplacian on closed submanifolds $M^n$ embedded in unit sphere $\mathbb{S}^{n+m}$. this study, we extend these results to $p$-Laplacian. As consequence, provide new characterizations $\mathbb{S}^n$. Additionally, derive integral inequalities terms norm second fundamental form $M$ and first non-zero eigenvalue $p$-Laplacian, thereby generalizing previously by Santos Soares~\cite{fabio23} hypersurfaces.
Abstract The aim of this paper is to prove a sharp inequality for the area four dimensional compact Einstein manifold (Σ, g Σ ) embedded into complete five ( M 5 , with positive scalar curvature R and nonnegative Ricci curvature. Under suitable choice, we have $area(\Sigma)^{\frac{1}{2}}\inf_{M}R \leq 8\sqrt{6}\pi$ . Moreover, occurring equality deduce that isometric standard sphere $\mathbb{S}$ 4 can in neighbourhood Σ, splits as ((-ϵ, ϵ) × dt 2 + Riemannian covering $\Bbb{R}$
We study foliations of space forms by complete hypersurfaces, under some mild conditions on its higher order mean curvatures. In particular, in Euclidean we obtain a Bernstein-type theorem for graphs whose and scalar curvature do not change sign but may otherwise be nonconstant. also establish the nonexistence standard sphere leaves are have constant curvature, thus extending Barbosa, Kenmotsu Oshikiri. For more general case {\em r-}minimal space, possibly with singular set, able to invoke...
The main goal of this paper is to present a complete description all translation hypersurfaces with constant r -curvature S , in the Euclidean space ℝ n + 1 where 3 ≤ - .
Abstract We present a complete description of all rotational linear Weingarten hypersurfaces in the Euclidean sphere S n+1 . These are characterized by relation aH 1 +bH 2 = c, where H and stand for first two symmetric functions principal curvature a, b c real constants.
Abstract The aim of the paper is to present a classification nonextendable immersed O( p +1) × q + 1)-invariant ( r – 1)-minimal hypersurfaces in Euclidean space , with p, > 1 and 2 ≤ min{ }, by analyzing embeddedness as well 1)-stability. case = were treated [Alencar, Trans. Amer. Math. Soc. 337: 129–141, 1993] [Sato, de Souza Neto, Ann. Global Anal. Geom. 29: 221–240, 2006], respectively. Generalizing seminal work Bombieri et al. we also 1)-stable complete embedded hypersurface H 0 1)...
Vermiculite clays are adsorbent materials that have good chemical adsorption capacity, which makes them applicable in the removal of drugs from aqueous solutions. Their lamellar structure can be easily expanded and organophilized. To assess efficacy environmentally-tolerant capacity method, organophilized vermiculite clay was compared to both natural clays. prepare clays, a sample at 900 °C. The thus treated by immersion 1.0 M NaCl solution using cetyltrimethylammonium bromide (CTMA-Br)...