Results 121 to 130 of about 3,042 (217)

Bounded exponential sums with multiplicative coefficients

Mathematika, Volume 72, Issue 4, October 2026.
Abstract We investigate when the exponential sum Sf(x,α):=∑n⩽xf(n)e(nα)$S_f(x,\alpha) := \sum _{n\leqslant x}f(n)\mathrm{e}(n\alpha)$ is bounded, for a multiplicative function f$f$ and α∈R$\alpha \in \mathbb {R}$. We show that under natural assumptions, Sf(x,α)$S_f(x,\alpha)$ is bounded only when f$f$ is very close to a twisted Dirichlet character χ(n ...
Péa Bazin, Ihor Pylaiev, Fred Tyrrell
wiley   +1 more source

Algebraic Invariants for Inferring 4-Leaf Semi-Directed Phylogenetic Networks. [PDF]

Syst Biol
Martin S, Holtgrefe N, Moulton V, Leggett RM.   +3 more
europepmc   +1 more source

Colourings of Uniform Group Divisible Designs and Maximum Packings

Journal of Combinatorial Designs, Volume 34, Issue 9, Page 437-456, September 2026.
ABSTRACT A weak c‐colouring of a design is an assignment of colours to its points from a set of c available colours, such that there are no monochromatic blocks. A colouring of a design is block‐equitable, if for each block, the number of points coloured with any available pair of colours differ by at most one.
Andrea C. Burgess, Peter Danziger, Diane Donovan, Tara Kemp, James G. Lefevre, David A. Pike, E. Şule Yazıcı   +6 more
wiley   +1 more source

On Hodge polynomials for nonalgebraic complex manifolds. [PDF]

Proc Natl Acad Sci U S A
Katzarkov L, Lee KS, Lupercio E, Meersseman L.   +3 more
europepmc   +1 more source

Signed Projective Cubes, a Homomorphism Point of View

Journal of Graph Theory, Volume 113, Issue 1, Page 38-56, September 2026.
ABSTRACT The (signed) projective cubes, as a special class of graphs closely related to the hypercubes, are on the crossroad of geometry, algebra, discrete mathematics and linear algebra. Defined as Cayley graphs on binary groups, they represent basic linear dependencies.
Meirun Chen, Reza Naserasr, Alessandra Sarti   +2 more
wiley   +1 more source

Fixed-point topology meets fractal memory: a Kutumba-stabilized framework for nonlocal fractal-fractional dynamics. [PDF]

Sci Rep
Devi RA, Surendar R, Sweatha S, Saeed ST, Almehizia AA, Saleh MA, Merga FE.   +6 more
europepmc   +1 more source

Physics‐Guided Neural Network for Quantitative Parameter Mapping Using Balanced Steady State Free Precession MRI

Magnetic Resonance in Medicine, Volume 96, Issue 3, Page 1313-1322, September 2026.
ABSTRACT Purpose To propose a new method using a physics‐guided neural network for quantitative parameter mapping in balanced steady‐state free precession (bSSFP) imaging. Theory and Methods We trained physics‐guided neural networks with a multilayer perceptron using simulated bSSFP signals generated from tissue parameters (T1, T2,Meffc, ∆f and φRF ...
Hye‐Ryeong Choi, Huan Minh Luu, Sung‐Hong Park   +2 more
wiley   +1 more source

Some generalized recurrence relations for nonlinear equations by using decomposition technique with application of fractal geometry. [PDF]

MethodsX
Shah FA, Hamdani SR, Tolasa FT, Haider I.   +3 more
europepmc   +1 more source

Four Directions, One Solution: Enabling Rapid Diffusion Tensor MRI for Ultra‐Low Field Using Deep Learning

Magnetic Resonance in Medicine, Volume 96, Issue 3, Page 1413-1426, September 2026.
ABSTRACT Purpose This study revisits the tetrahedral encoding strategy originally proposed to accelerate Diffusion Tensor Magnetic Resonance Imaging (DT‐MRI) by reducing the requisite number of diffusion‐weighted measurements to four. We examine its practical limitations and explore how artificial intelligence (AI) can extend its utility. Specifically,
Joshua Mawuli Ametepe, James Gholam, Leandro Beltrachini, Mara Cercignani, Derek Kenton Jones   +4 more
wiley   +1 more source

A note on a generalized double series. [PDF]

PLoS One
Reynolds R.
europepmc   +1 more source