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We compute the cohomology of the right generalised projective Stiefel manifolds and use it to find bounds on the rank of the complementary bundle for certain vector bundles. Further the cohomology computations are also used to find bounds…

Algebraic Topology · Mathematics 2019-08-15 Samik Basu , B. Subhash

The recently introduced collaborative nonnegative matrix factorization (CoNMF) algorithm was conceived to simultaneously estimate the number of endmembers, the mixing matrix, and the fractional abundances from hyperspectral linear mixtures.…

Optimization and Control · Mathematics 2016-09-21 Jun Li , Jose M. Bioucas-Dias , Antonio Plaza , Lin Liu

We develop a new analytic method for quantitative mixing of automorphisms on nilmanifolds. The method is based on the introduction and solvability of \emph{multiple fractional cohomological equations of Type~$I$} (sum type). We prove that…

Dynamical Systems · Mathematics 2026-05-19 Zhenqi Jenny Wang

By studying cohomology classes that are related with $n$-harmonic morphisms and $F$-harmonic maps, we augment and extend several results on $F$-harmonic maps, harmonic maps in [1, 3, 14], $p$-harmonic morphisms in [17], and also revisit our…

Differential Geometry · Mathematics 2023-08-22 Bang-Yen Chen , Shihshu Walter Wei

Let X be a 1-connected compact space such that the algebra H*(X;Z/2) is generated by one single element. We compute the cohomology of the free loop space H*(LX;Z/2) including the Steenrod algebra action. When X is a projective space CP^n,…

Algebraic Topology · Mathematics 2007-05-23 Marcel Bokstedt , Iver Ottosen

We introduce and study properties of certain new harmonic function spaces on products of upper half-spaces.Norm estimates for the so-called expanded Bergman projections are obtained.Sharp theorems on multipliers acting on certain Sobolev…

Functional Analysis · Mathematics 2012-01-18 Milos Arsenovic , Romi F. Shamoyan

By utilizing elementary techniques from toric geometry, we prove sharp cohomological vanishing results for line bundles defined on the blow-up of projective space $\mathbb{P}^n$ at no more than $n+1$ points.

Algebraic Geometry · Mathematics 2024-11-19 Marco Flores

We consider finite-dimensional Hopf algebras $u$ which admit a smooth deformation $U\to u$ by a Noetherian Hopf algebra $U$ of finite global dimension. Examples of such Hopf algebras include small quantum groups over the complex numbers,…

Representation Theory · Mathematics 2021-01-01 Cris Negron , Julia Pevtsova

In this paper we use techniques from convex projective geometry to produce many new examples of thin subgroups of lattices in special linear groups that are isomorphic to the fundamental groups of finite volume hyperbolic manifolds. More…

Geometric Topology · Mathematics 2020-07-29 Samuel Ballas , D. D. Long

We compute the integral homology and cohomology groups of configuration spaces of two distinct points on a given real projective space. The explicit answer is related to the (known multiplicative structure in the) integral cohomology---with…

Algebraic Topology · Mathematics 2012-01-24 Jesus Gonzalez , Peter Landweber

The $s$-th higher topological complexity of a space $X$, $TC_s(X)$, can be estimated from above by homotopical methods, and from below by homological methods. We give a thorough analysis of the gap between such estimates when $X=RP^m$, the…

Algebraic Topology · Mathematics 2016-09-27 Natalia Cadavid , Jesús González , Aldo Guzmán-Sáenz

We extend the Tian approximation theorem for projective manifolds to a class of complex non-K\"ahler manifolds, the so-called Vaisman manifolds. More precisely, we study the problem of approximating compact regular, respectively…

Differential Geometry · Mathematics 2024-08-05 Daniele Angella , Marco Miceli , Giovanni Placini

In this paper, we propose a new numerical scheme for a spatially discrete model of constrained total variation flows, which are total variation flows whose values are constrained in a Riemannian manifold. The difficulty of this problem is…

Analysis of PDEs · Mathematics 2020-05-05 Yoshikazu Giga , Koya Sakakibara , Kazutoshi Taguchi , Masaaki Uesaka

Let PConf^n M be the configuration space of ordered n-tuples of distinct points on a smooth manifold M admitting a nowhere-vanishing vector field. We show that the ith cohomology group with coefficients in a field H^i(PConf^n M, k) is an…

Algebraic Topology · Mathematics 2019-04-16 Jordan S. Ellenberg , John D. Wiltshire-Gordon

We study the behaviour of Tikhonov regularisation on topological spaces with multiple regularisation terms. The main result of the paper shows that multi-parameter regularisation is well-posed in the sense that the results depend…

Numerical Analysis · Mathematics 2011-09-05 Markus Grasmair

We obtain new mean value theorems for exponential sums with very smooth numbers, which provide a power saving against the trivial bound in region where previous bounds do not apply.

Number Theory · Mathematics 2025-06-30 F. Majeed , Igor E. Shparlinski

Kontsevich and Rosenberg propose to study smooth noncommutative spaces by approximation at level n by representation spaces. In this note we make some comments about their proposal.

Algebraic Geometry · Mathematics 2009-09-25 Lieven Le Bruyn

In previous work, we proposed a general framework of positive topological field theories (TFTs) based on Eilenberg's notion of summation completeness for semirings. In the present paper, we apply this framework in constructing explicitly a…

Algebraic Topology · Mathematics 2015-08-07 Markus Banagl

We present a pedagogical review of projective representations of finite groups and their physical applications in quantum many-body systems. Some of our physical results are new. We begin with a self-contained introduction to projective…

Strongly Correlated Electrons · Physics 2026-02-23 Ryohei Kobayashi , Haruki Watanabe

We show two sphere theorems for the Riemannian manifolds with scalar curvature bounded below and the non-collapsed $\mathrm{RCD}(n-1,n)$ spaces with mean distance close to $\frac{\pi}{2}$.

Differential Geometry · Mathematics 2022-06-06 Jialong Deng