Publications related to Frame bundle

Bundle-Specific Axon Diameter Index as a New Contrast to Differentiate White Matter Tracts

Jean-Philippe Thiran, David Paul Roger Romascano, Gabriel Girard, Alessandro Daducci, Cristina Granziera, Muhamed Barakovic, Maxime Descoteaux, Giorgio Innocenti

In the central nervous system of primates, several pathways are characterized by different spectra of axon diameters. In vivo methods, based on diffusion-weighted magnetic resonance imaging, can provide axon diameter index estimates non-invasively. However ...

2021

Three-dimensional fabrication of sub-micron optical waveguides in PDMS and other polymer materials

Giulia Panusa

Optical waveguides are one of the most important photonic components. They are indispensable tools in many of todayâ s technologies because of their capacity of guiding light. In particular, compact, low loss, flexible polymer optical waveguides are cruci ...

EPFL2021

Resolving bundle-specific intra-axonal T2 values within a voxel using diffusion-relaxation tract-based estimation

Jean-Philippe Thiran, Erick Jorge Canales Rodriguez, Alessandro Daducci, Muhamed Barakovic, Cristina Granziera

At the typical spatial resolution of MRI in the human brain, approximately 60–90% of voxels contain multiple fiber populations. Quantifying microstructural properties of distinct fiber populations within a voxel is therefore challenging but necessary. Whil ...

2020

Arithmetically rigid schemes via deformation theory of equivariant vector bundles

Maciej Emilian Zdanowicz

We analyze the deformation theory of equivariant vector bundles. In particular, we provide an effective criterion for verifying whether all infinitesimal deformations preserve the equivariant structure. As an application, using rigidity of the Frobenius ho ...

SPRINGER HEIDELBERG2021

Characteristic classes as complete obstructions

Martina Rovelli

In the first part of this paper, we propose a uniform interpretation of characteristic classes as obstructions to the reduction of the structure group and to the existence of an equivariant extension of a certain homomorphism defined a priori only on a sin ...

SPRINGER HEIDELBERG2019

Fréchet means and Procrustes analysis in Wasserstein space

Victor Panaretos, Yoav Zemel

We consider two statistical problems at the intersection of functional and non-Euclidean data analysis: the determination of a Fréchet mean in the Wasserstein space of multivariate distributions; and the optimal registration of deformed random measures and ...

2019

Frame (in)equivalence in quantum field theory and cosmology

Mario Herrero Valea

We revisit the question of frame equivalence in Quantum Field Theory in the presence of gravity, a situation of relevance for theories aiming to describe the early Universe dynamics and Inflation in particular. We show that in those cases, the path integra ...

Springer2019

A Looping-Delooping Adjunction For Topological Spaces

Martina Rovelli

Every principal G-bundle over X is classified up to equivalence by a homotopy class X -> BG, where BG is the classifying space of G. On the other hand, for every nice topological space X Milnor constructed a strict model of its loop space (Omega) over tild ...

Int Press Boston, Inc2017

Towards new invariants for principal bundles

Martina Rovelli

We investigate the theory of principal bundles from a homotopical point of view. In the first part of the thesis, we prove a classification of principal bundles over a fixed base space, dual to the well-known classification of bundles with a fixed structur ...

EPFL2017

Fréchet means in Wasserstein space : theory and algorithms

Yoav Zemel

This work studies the problem of statistical inference for Fréchet means in the Wasserstein space of measures on Euclidean spaces,

\mathcal W_2 ( \mathbb R^d )

. This question arises naturally from the problem of separating amplitude and phase variation i ...

EPFL2017

Reconstructing Evolving Tree Structures in Time Lapse Sequences by Enforcing Time-Consistency

Pascal Fua, Engin Türetken, Raphael Sznitman, Jan Kybic, Agata Justyna Mosinska, Przemyslaw Rafal Glowacki, Miguel Amável Dos Santos Pinheiro, Daniel Lebrecht

We propose a novel approach to reconstructing curvilinear tree structures evolving over time, such as road networks in 2D aerial images or neural structures in 3D microscopy stacks acquired in vivo. To enforce temporal consistency, we simultaneously proces ...

2017

Unified prefetching into instruction cache and branch target buffer

Babak Falsafi, Boris Robert Grot, Ilknur Cansu Kaynak

A system and method of coupling a Branch Target Buffer (BTB) content of a BTB with an instruction cache content of an instruction cache. The method includes: tagging a plurality of target buffer entries that belong to branches within a same instruction blo ...

2017

Two-photon excitation endoscopy through a multimode optical fiber

Demetri Psaltis, Christophe Moser, Edgar Emilio Morales Delgado

The vast number of propagating solutions to the wave equation in multimode optical fibers represents a larger information capacity than provided by fiber bundles of the same diameter. Therefore, in the field of imaging, multimode fibers potentially allow t ...

Spie-Int Soc Optical Engineering2016

Fiber bundle model under fluid pressure

Internal fluid pressure often plays an important role in the rupture of brittle materials. This is a major concern for many engineering applications and for natural hazards. More specifically, the mechanisms through which fluid pressure, applied at a micro ...

Amer Physical Soc2016

Dendrimer-Stabilized Titanate Nanowire Dispersions as Potential Nanocarriers

László Forró, Endre Horvath, Marko Pavlovic

The effect of poly(amido amine) (PAMAM) dendrimers of generations G2, G6, and G10 on the dispersion stability of titanate nanowires (TiONWs) as potential nanocarriers was clarified in order to develop biocompatible delivery systems. The PAMAMs adsorbed str ...

Amer Chemical Soc2015

Conjugation spaces and equivariant Chern classes

Jérôme Scherer

Let eta be a Real bundle, in the sense of Atiyah, over a space X. This is a complex vector bundle together with an involution which is compatible with complex conjugation. We use the fact that BU has a canonical structure of a conjugation space, as defined ...

Belgian Mathematical Soc Triomphe2013

Equivariant K-theory of GKM bundles

Silvia Sabatini

Given a fiber bundle of GKM spaces, pi: M -> B, we analyze the structure of the equivariant K-ring of M as a module over the equivariant K-ring of B by translating the fiber bundle, pi, into a fiber bundle of GKM graphs and constructing, by combinatorial t ...

Springer Netherlands2013

Hecke modifications, wonderful compactifications and moduli of principal bundles

Michael Lennox Wong

In this paper we obtain parametrizations of the moduli space of principal bundles over a compact Riemann surface using spaces of Hecke modifications in several cases. We begin with a discussion of Hecke modifications for principal bundles and give construc ...

Scuola Normale Superiore2013

Balanced Fiber Bundles and GKM Theory

Silvia Sabatini

Let T be a torus and B a compact T-manifold. Goresky et al. show in [3] that if B is (what was subsequently called) a GKM manifold, then there exists a simple combinatorial description of the equivariant cohomology ring H-T*(B) as a subring of H-T*(B-T). I ...

Oxford University Press2013

An actin length threshold regulates adhesion maturation at the lamellipodium/lamellum interface

Jean-Jacques Meister, Benoît Vianay, Céline Jeanne Labouesse

The mechanical coupling between adherent cells and their substrates is a major driver of downstream behavior. This coupling relies on the formation of adhesion sites and actin bundles. How cells generate these elements remains only partly understood. A pot ...

Royal Soc Chemistry2013