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The initial sections of the paper give a concise presentation, specially designed for a mathematically oriented audience, of some of the most basic facts on the functional architecture of early vision. Such information is usually scattered…

Neurons and Cognition · Quantitative Biology 2024-10-29 Dmitri V. Alekseevsky , Andrea Spiro

The purpose of this work is to construct a model for the functional architecture of the primary visual cortex (V1), based on a structure of metric measure space induced by the underlying organization of receptive profiles (RPs) of visual…

Metric Geometry · Mathematics 2019-10-14 Noemi Montobbio , Alessandro Sarti , Giovanna Citti

Contact Geometry is an odd dimensional analogue of Symplectic Geometry. This vague idea can actually be formalized in a rather precise way by means of a Symplectic-to-Contact Dictionary. The aim of this review paper is discussing the basic…

Differential Geometry · Mathematics 2026-02-02 Fabrizio Pugliese , Giovanni Sparano , Luca Vitagliano

If $\eta$ is a contact form on a manifold $M$ such that the orbits of the Reeb vector field form a simple foliation $\mathcal{F}$ on $M$, then the presymplectic 2-form $d\eta$ on $M$ induces a symplectic structure $\omega$ on the quotient…

Symplectic Geometry · Mathematics 2024-11-04 Katarzyna Grabowska , Janusz Grabowski , Marek Kuś , Giuseppe Marmo

This article sketches various ideas in contact geometry that have become useful in low-dimensional topology. Specifically we (1) outline the proof of Eliashberg and Thurston's results concerning perturbations of foliatoins into contact…

Geometric Topology · Mathematics 2007-05-23 John B. Etnyre

We propose a novel approach to contact Hamiltonian mechanics which, in contrast to the one dominating in the literature, serves also for non-trivial contact structures. In this approach Hamiltonians are no longer functions on the contact…

Symplectic Geometry · Mathematics 2022-11-03 Katarzyna Grabowska , Janusz Grabowski

We model the functional architecture of the early stages of three-dimensional vision by extending the neurogeometric sub-Riemannian model for stereo-vision introduced in \cite{BCSZ23}. A new framework for correspondence is introduced that…

Neurons and Cognition · Quantitative Biology 2024-10-07 Maria Virginia Bolelli , Giovanna Citti , Alessandro Sarti , Steven W. Zucker

In this paper we develop a geometrical model of functional architecture for the processing of spatio-temporal visual stimuli. The model arises from the properties of the receptive field linear dynamics of orientation and speed-selective…

Analysis of PDEs · Mathematics 2013-05-06 Davide Barbieri , Giovanna Citti , Giacomo Cocci , Alessandro Sarti

The classical construction of the symplectic structure on the space of geodesic trajectories via Hamiltonian reduction fails in the pseudo-Riemannian setting due to a dimensional mismatch created by the null geodesics. This paper proposes a…

Differential Geometry · Mathematics 2025-10-08 Patrick Iglesias-Zemmour

We propose a framework for jointly modeling the geometry and functionality in high dimensional functional surfaces. The proposed mixed effects model characterizes effects of subject-specific covariates and exogenous stimuli on functional…

Applications · Statistics 2023-02-10 Jingjing Zou , Chi-Hua Chen , John A. D. Aston

We introduce length dilatation structures on metric spaces, tempered dilatation structures and coherent projections and explore the relations between these objects and the Radon-Nikodym property and Gamma-convergence of length functionals.…

Differential Geometry · Mathematics 2019-02-18 Marius Buliga

This paper studies distributed-parameter systems on Riemannian manifolds with respect to Stokes-Dirac structures in a language of contact geometry with fiber bundles. For the class where energy functionals are quadratic, it is shown that…

Mathematical Physics · Physics 2017-02-22 Shin-itiro Goto

We develop a neurogeometric model for the arm area of motor cortex, which encodes complex motor primitives, ranging from simple movement features like movement direction, to short hand trajectories, termed fragments, and ultimately to more…

Neurons and Cognition · Quantitative Biology 2026-02-13 Caterina Mazzetti , Jawad Ali , Alessandro Sarti , Giovanna Citti

Due to the emergence of symplectic geometry, the geometric treatment of mechanics underwent a great development during the last century. In this scenario the pressence of symmetries in Hamiltonian systems leads naturally to the existence of…

Mathematical Physics · Physics 2022-08-24 Juan Manso García-Mauriño

Whether it be in a man-made machine or a biological system, form and function are often directly related. In the latter, however, this particular relationship is often unclear due to the intricate nature of biology. Here we developed a…

Neurons and Cognition · Quantitative Biology 2020-05-27 Fernanda L. Ribeiro , Steffen Bollmann , Alexander M. Puckett

In this paper we first recall the definition of geometical model of the visual cortex, focusing in particular on the geometrical properties of horizontal cortical connectivity. Then we recognize that histograms of edges - co-occurrences are…

Computer Vision and Pattern Recognition · Computer Science 2019-06-11 Giovanna Citti , Alessandro Sarti

Mapping the brain imaging data to networks, where each node represents a specific area of the brain, has enabled an objective graph-theoretic analysis of human connectome. However, the latent structure on higher-order connections remains…

Neurons and Cognition · Quantitative Biology 2019-04-09 Bosiljka Tadic , Miroslav Andjelkovic , Roderick Melnik

Integrable Hamiltonian systems on symplectic manifolds have been well-studied. However, an intrinsic property of these kind of systems is that they can only live on even dimensional manifolds. To introduce a similar notion of integrability…

Dynamical Systems · Mathematics 2023-05-08 Senne Ignoul

We show that contact reductions can be described in terms of symplectic reductions in the traditional Marsden-Weinstein-Meyer as well as the constant rank picture. The point is that we view contact structures as particular (homogeneous)…

Symplectic Geometry · Mathematics 2025-05-12 Katarzyna Grabowska , Janusz Grabowski

We introduce a new method to perform reduction of contact manifolds that extends Willett's (math.SG/0104080) and Albert's results. To carry out our reduction procedure all we need is a complete Jacobi map $J$ from a contact manifold $M$ to…

Differential Geometry · Mathematics 2007-05-23 Marco Zambon , Chenchang Zhu
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