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Related papers: Non-strongly isospectral spherical space forms

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This paper presents a theoretical study of the phenomenon of acoustic imaging by sonic crystals, which are made of two-dimensional regular arrays of rigid cylinders placed in parallel in air. The scattering of acoustic waves is computed…

Materials Science · Physics 2009-11-10 Chao-Hsien Kuo , Zhen Ye

A basilar property and a useful tool in the theory of Sobolev spaces is the density of smooth compactly supported functions in the space $W^{k,p}(\R^n)$ (i.e. the functions with weak derivatives of orders $0$ to $k$ in $L^p$). On Riemannian…

Analysis of PDEs · Mathematics 2023-02-15 Giona Veronelli

We study the correlation between the locations of galaxy-galaxy strong lensing candidates and tracers of large-scale structure from both weak lensing or X-ray emission. The COSMOS survey is a unique data set, combining deep, high resolution…

The key to using a strong gravitational lens system to measure the Hubble constant is to obtain an accurate model of the lens potential. In this paper, we investigate the properties of gravitational lens B1608+656, a quadruply-imaged lens…

Astrophysics · Physics 2009-11-13 S. H. Suyu , R. D. Blandford

A surface functional theory for p-dimensional extended objects, the p-branes, was proposed in previous papers. The field equations for toroidal p-branes was exactly solved in $d=p+2$ dimensions, yielding equally spaced mass-squared spectrum…

High Energy Physics - Theory · Physics 2010-11-19 Choon-Lin Ho

We give a survey of analytic and geometric results on `fibred cusp spaces', a large class of non-compact Riemannian manifolds which include the regular parts of singular spaces with incomplete cusp singularities as well as complete spaces…

Differential Geometry · Mathematics 2026-04-20 Daniel Grieser , Álvaro Sánchez-Hernández , Boris Vertman

$\Gamma$-structures are weak forms of multiplications on closed oriented manifolds. As shown by Hopf the rational cohomology algebras of manifolds admitting $\Gamma$-structures are free over odd degree generators. We prove that this…

Differential Geometry · Mathematics 2018-03-16 Bernhard Hanke , Peter Quast

The "weakly Hausdorff" property for pseudoradial spaces fails to be naturally characterized by unique convergence of transfinite sequences. In response, we develop the category $\mathbf{SPsRad}$ of strongly pseudoradial spaces, compactly…

General Topology · Mathematics 2017-03-14 Jeremy Brazas , Paul Fabel

Functional determinants for a single scalar field with negative mass squared are evaluated on homogeneous lens spaces. For example, on even order spaces, the Hartle--Hawking wave function oscillates about its zeros with increasing amplitude…

High Energy Physics - Theory · Physics 2014-04-15 J. S. Dowker

Extensions of singular spectrum analysis (SSA) for processing of non-rectangular images and time series with gaps are considered. A circular version is suggested, which allows application of the method to the data given on a circle or on a…

Methodology · Statistics 2015-07-13 Alex Shlemov , Nina Golyandina

We study the problem of constructing an optical surface separating two homogeneous, isotropic media, one of which has a negative refractive index. In doing so, we develop a vector form of Snell's law, which is used to study surfaces…

Optics · Physics 2023-07-19 Cristian E. Gutierrez , Eric Stachura

Using squeezed vacuum state formalism of quantum optics, an approximate solution to the semiclassical Einstein equation is obtained in Bianchi type-I universe. The phenomena of nonclassical particle creation is also examined in the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 P. K. Suresh

We extend the ideas of the recently proposed perfect lens [J.B. Pendry, Phys. Rev. Lett. {\bf 85}, 3966 (2000)] to an alternative structure. We show that a slab of a medium with negative refractive index bounded by media of different…

Condensed Matter · Physics 2009-11-07 S. Anantha Ramakrishna , J. B. Pendry , D. Schurig , D. R. Smith , S. Schultz

Piecewise Euclidean structures (identified solid Euclidean polyhedra) on topological 3-dimensional manifolds and pseudo-manifolds are constructed so that they admit pseudo-foliations, a generalized type of foliation. The construction of…

Differential Geometry · Mathematics 2007-05-23 Simon P Morgan

We give a complete classification of isoparametric hypersurfaces in a product space $M^2_{\kappa_1}\times M^2_{\kappa_2}$ of $2$-dimensional space forms for $\kappa_i\in \{-1,0,1\}$ with $\kappa_1\neq \kappa_2$. In fact we prove that any…

Differential Geometry · Mathematics 2023-09-28 Dong Gao , Hui Ma , Zeke Yao

Applying the distance sum rule in strong gravitational lensing (SGL) and type Ia supernova (SN Ia) observations, one can provide an interesting cosmological model-independent method to determine the cosmic curvature parameter $\Omega_k$. In…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-31 Bo Wang , Jing-Zhao Qi , Jing-Fei Zhang , Xin Zhang

We provide a strengthening of Jordan separation, to the setting of maps from a compact topological space X into a sphere, where the source space X is not necessarily a codimension one sphere, and the map is not necessarily injective.

Geometric Topology · Mathematics 2009-07-17 J. -F. Lafont

We prove that the moduli spaces of K3 surfaces with non-symplectic involutions are unirational. As a by-product we describe configuration spaces of 4<d<9 points in the projective plane as arithmetic quotients of type IV.

Algebraic Geometry · Mathematics 2014-02-26 Shouhei Ma

It was proposed that a flat silver layer could be used to form a sub-diffraction limited image when illuminated near its surface plasmon resonance frequency [J. B. Pendry, Phys. Rev. Lett. 86, 3966 (2000)]. In this paper, we study the…

Optics · Physics 2014-08-26 Avner Yanai , Uriel Levy

With the availability of thousands of type Ia supernovae in the near future the magnitude scatter induced by lensing will become a major issue as it affects parameter estimation. Current N-body simulations are too time consuming to be…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-10 Valerio Marra , Miguel Quartin , Luca Amendola