Results 51 to 60 of about 4,520 (139)
Abstract String theory has strong implications for cosmology, implying the absence of a cosmological constant, ruling out single‐field slow‐roll inflation, and that black holes decay. The origins of these statements are elucidated within the string‐theoretical swampland programme.
Kay Lehnert
wiley +1 more source
Nearly Kähler manifolds with positive holomorphic sectional curvature [PDF]
Two problems are studied for connected compact nearly Kähler manifolds \((M,g,J)\), i.e. almost Hermitian manifolds such that \((\nabla_ XJ)X=0\) for all vector fields \(X\). First, when \(M\) is an Einstein manifold, the authors derive an integral formula on the unit sphere bundle over M.
Sekigawa, Kouei, Sato, Takuji
openaire +3 more sources
ABSTRACT In this paper, we continue the development of the Cartan neural networks programme, launched with three previous publications, by focusing on some mathematical foundational aspects that we deem necessary for our next steps forward. The mathematical and conceptual results are diverse and span various mathematical fields, but the inspiring ...
Pietro Fré +4 more
wiley +1 more source
Positivity and Kodaira embedding theorem
Kodaira embedding theorem provides an effective characterization of projectivity of a K\"ahler manifold in terms the second cohomology. Recently X. Yang [21] proved that any compact K\"ahler manifold with positive holomorphic sectional curvature must be ...
Ni, Lei, Zheng, Fangyang
core
Almost contact metric 3-submersions
An almost contact metric 3-submersion is a Riemannian submersion, π from an almost contact metric manifold (M4m+3,(φi,ξi,ηi)i=13,g) onto an almost quaternionic manifold (N4n,(Ji)i=13,h) which commutes with the structure tensors of type (1,1);i.e., π*φi ...
Bill Watson
doaj +1 more source
GCD inequalities arising from codimension‐2 blowups
Abstract Assuming a deep Diophantine geometry conjecture by Vojta, Silverman proved an inequality giving an upper bound for the greatest common divisor (GCD). In this paper, we unconditionally prove a weaker version of this inequality. The main ingredient is the Ru–Vojta theory, which provides an efficient method of using Schmidt subspace theorem.
Yu Yasufuku
wiley +1 more source
A fractional residue theorem and its applications in calculating real integrals
Abstract As part of an ongoing effort to fractionalise complex analysis, we present a fractional version of the residue theorem, involving pseudo‐residues calculated at branch points. Since fractional derivatives are non‐local and fractional powers necessitate branch cuts, each pseudo‐residue depends on a line segment in the complex plane rather than a
Egor Zaytsev, Arran Fernandez
wiley +1 more source
A Miyaoka–Yau inequality for hyperplane arrangements in CPn$\mathbb {CP}^n$
Abstract Let H$\mathcal {H}$ be a hyperplane arrangement in CPn$\mathbb {CP}^n$. We define a quadratic form Q$Q$ on RH$\mathbb {R}^{\mathcal {H}}$ that is entirely determined by the intersection poset of H$\mathcal {H}$. Using the Bogomolov–Gieseker inequality for parabolic bundles, we show that if a∈RH$\mathbf {a}\in \mathbb {R}^{\mathcal {H}}$ is ...
Martin de Borbon, Dmitri Panov
wiley +1 more source
Multiple front and pulse solutions in spatially periodic systems
Abstract In this paper, we develop a comprehensive mathematical toolbox for the construction and spectral stability analysis of stationary multiple front and pulse solutions to general semilinear evolution problems on the real line with spatially periodic coefficients.
Lukas Bengel, Björn de Rijk
wiley +1 more source
Almost Kahler manifolds of constant holomorphic sectional curvature
Let \((M,g,J)\) be an almost Hermitian manifold. It is called an almost Kähler manifold if the Kähler form \(\Omega\) defined by \(\Omega(X,Y)= g(X,JY)\) is closed. S. I. Goldberg conjectured that a compact almost Kähler Einstein manifold is Kählerian (i.e., \(\nabla J=0)\).
openaire +2 more sources

