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With the idea of an eventual classification of 3-bridge links,\ we define a very nice class of 3-balls (called butterflies) with faces identified by pairs, such that the identification space is $S^{3},$ and the image of a prefered set of…

Algebraic Topology · Mathematics 2012-03-12 H. M. Hilden , J. M. Montesinos , D. M. Tejada , M. M. Toro

The need for wireless communication has driven the communication systems to high performance. However, the main bottleneck that affects the communication capability is the Fast Fourier Transform (FFT), which is the core of most modulators.…

Signal Processing · Electrical Eng. & Systems 2018-08-09 Rozita Teymourzadeh , Yazan Samir , Masuri Othman , Mok Vee Hong

We provide formulas for projectors onto a polyhedral set, i.e. the intersection of a finite number of halfspaces. To this aim we formulate the problem of finding the projection as a convex optimization problem and we solve explicitly…

Optimization and Control · Mathematics 2017-04-20 Krzysztof E. Rutkowski

This paper introduces the interpolative butterfly factorization for nearly optimal implementation of several transforms in harmonic analysis, when their explicit formulas satisfy certain analytic properties and the matrix representations of…

Numerical Analysis · Mathematics 2017-04-11 Yingzhou Li , Haizhao Yang

In this paper, we study holomorphic foliations of degree four on complex projective space $\mathbb{P}^n$, where $n\geq 3$, with a special focus on obtaining a structural theorem for these foliations. Furthermore, for a foliation…

Complex Variables · Mathematics 2023-08-22 Arturo Fernández-Pérez , Vângellis Sagnori Maia

A fibre product construction is used to give a description of quantum line bundles over the generic Podles spheres by gluing two quantum discs along their boundaries. Representatives of the corresponding $K_0$-classes are given in terms of…

Quantum Algebra · Mathematics 2009-02-24 Elmar Wagner

We construct a Petersson-Weil type K\"ahler form on the moduli spaces of Higgs bundles over a compact K\"ahler manifold. A fiber integral formula for this form is proved, from which it follows that the Petersson-Weil form is the curvature…

Algebraic Geometry · Mathematics 2007-05-23 Indranil Biswas , Georg Schumacher

The divertor in a magnetic confinement fusion reactor is an essential component for power dissipation and particle removal. The FIREFLY package for rapid evaluation of divertor designs is presented as an extension of the FLARE code for…

Plasma Physics · Physics 2026-04-14 Heinke Frerichs , Dieter Boeyaert , Yuhe Feng , Detlev Reiter

A recursive construction is presented for the projective cubature formulas of index $p$ on the unit spheres $S(m,K)\subset K^m$ where $K$ is $R$ or $C$, or $H$. This yields a lot of new upper bounds for the minimal number of nodes…

Functional Analysis · Mathematics 2014-05-26 Yuri I. Lyubich , Oksana A. Shatalova

We discuss representations of the projective line over a ring $R$ with 1 in a projective space over some (not necessarily commutative) field $K$. Such a representation is based upon a $(K,R)$-bimodule $U$. The points of the projective line…

Algebraic Geometry · Mathematics 2024-02-13 Andrea Blunck , Hans Havlicek

The Habitable-zone Planet Finder (HPF) is a highly stabilized fiber fed precision radial velocity (RV) spectrograph working in the Near Infrared (NIR): 810 - 1280 nm . In this paper we present an overview of the preparation of the optical…

We briefly describe the current version of the PHOENIX code. We then present some illustrative results from the modeling of Type Ia and Type II supernovae, hot stars, and irradiated giant planets. Good fits to observations can be obtained,…

On base of Hamiltonian formalism, we show that Hopf bifurcation arrives, in the course of the system evolution, at creation of revolving region of the phase plane being bounded by limit cycle. A revolving phase plane with a set of limit…

Statistical Mechanics · Physics 2007-05-23 A. I. Olemskoi , I. A. Shuda

The principles and practice of astronomical imaging Fourier transform spectroscopy (FTS) at far-infrared wavelengths are described. The Mach-Zehnder interferometer design has been widely adopted for current and future imaging FTS…

Instrumentation and Methods for Astrophysics · Physics 2013-10-10 David A. Naylor , Brad G. Gom , Matthijs H. D. van der Wiel , Gibion Makiwa

The Poincar\'e sphere is a graphical representation in a three-dimensional space for the polarization of light. Similarly, an optical element with spatially varying birefringence can be represented by a surface on a four-dimensional…

Optics · Physics 2018-02-14 Anthony Vella , Miguel A. Alonso

We present WOFRY (Wave Optics FRamework in pYthon), a specialized toolbox designed for wave optics modeling, with particular emphasis on partial coherence. This package is tailored to assist synchrotron scientists and engineers in the…

A quasi-projection pair consists of two operators $P$ and $Q$ acting on a Hilbert $C^*$-module $H$, where $P$ is a projection and $Q$ is an idempotent satisfying $Q^*=(2P-I)Q(2P-I)$, in which $Q^*$ denotes the adjoint operator of $Q$, and…

Functional Analysis · Mathematics 2025-11-03 Xiaoyi Tian , Qingxiang Xu , Chunhong Fu

This paper is concerned with the fast computation of Fourier integral operators of the general form $\int_{\R^d} e^{2\pi\i \Phi(x,k)} f(k) d k$, where $k$ is a frequency variable, $\Phi(x,k)$ is a phase function obeying a standard…

Numerical Analysis · Mathematics 2008-09-05 Emmanuel Candes , Laurent Demanet , Lexing Ying

A spectrahedron is a set defined by a linear matrix inequality. A projection of a spectrahedron is often called a semidefinitely representable set. We show that the convex hull of a finite union of such projections is again a projection of…

Optimization and Control · Mathematics 2009-08-25 Tim Netzer , Rainer Sinn

A classical result asserts that the complex projective plane modulo complex conjugation is the 4-dimensional sphere. We generalize this result in two directions by considering the projective planes over the normed real division algebras and…

Differential Geometry · Mathematics 2007-05-23 Michael Atiyah , Jurgen Berndt