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We investigate how strong lensing of dusty, star-forming galaxies by foreground galaxies can be used as a probe of dark matter halo substructure. We find that spatially resolved spectroscopy of lensed sources allows dramatic improvements to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Yashar Hezaveh , Neal Dalal , Gilbert Holder , Michael Kuhlen , Daniel Marrone , Norman Murray , Joaquin Vieira

A number of years ago, Kumar Murty pointed out to me that the computation of the fundamental group of a Hilbert modular surface ([7],IV,${\S}$6), and the computation of the congruence subgroup kernel of SL(2) ([6]) were surprisingly…

Algebraic Geometry · Mathematics 2017-08-02 John Scherk

We derive the density profile for collisionless dissipationless dark matter haloes in hierarchical cosmologies making use of the Secondary Infall (SI) model. The novelties are: i) we deal with triaxial virialised objects; ii) their seeds in…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-10 Eduard Salvador-Solé , Jordi Viñas , Alberto Manrique , Sinue Serra

In this paper, we develop a method for estimating and clustering two-dimensional spectral density functions (2D-SDFs) for spatial data from multiple subregions. We use a common set of adaptive basis functions to explain the similarities…

Methodology · Statistics 2020-07-29 Tianbo Chen , Ying Sun , Mehdi Maadooliat

We argue that a universal density profile for dark matter halos arises as a natural consequence of hierarchical structure formation. It is a fixed point in the process of repeated mergers. We present analytic and numerical arguments for the…

Astrophysics · Physics 2008-02-03 D. Syer , Simon D. M. White

We consider complexes $(\X, d)$ of nuclear Fr\'echet spaces and continuous boundary maps $d_n$ with closed ranges and prove that, up to topological isomorphism, $ (H_{n}(\X, d))^*$ $\iso$ $H^{n}(\X^*,d^*),$ where $(H_{n}(\X,d))^*$ is the…

K-Theory and Homology · Mathematics 2007-09-13 Zinaida A. Lykova

We study the construction of coresets for kernel density estimates. That is we show how to approximate the kernel density estimate described by a large point set with another kernel density estimate with a much smaller point set. For…

Machine Learning · Computer Science 2017-10-13 Jeff M. Phillips , Wai Ming Tai

In this work we want to study the average mass density profile of tens to hundreds of clusters of galaxies acting as lenses that produce a magnification bias on the SMGs, and to estimate their associated masses and concentrations for…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-26 L. Fernandez , M. M. Cueli , J. González-Nuevo , L. Bonavera , D. Crespo , J. M. Casas , A. Lapi

We prove a filtered version of the Homotopy Transfer Theorem which gives an A-infinity algebra structure on any page of the spectral sequence associated to a filtered dg-algebra. We then develop various applications to the study of the…

Algebraic Topology · Mathematics 2022-10-19 Joana Cirici , Anna Sopena

Consider the variational bicomplex for $\mathcal{E}$ the space of sections of a graded, affine bundle. Local functionals $\mathcal{F}$ are defined as an equivalence class of density-valued functionals, which represent Lagrangian densities.…

Mathematical Physics · Physics 2025-09-17 Michele Schiavina , Jonas Schnitzer

A host algebra of a topological group G is a C^*-algebra whose representations are in one-to-one correspondence with certain continuous unitary representations of G. In this paper we present an approach to host algebras for infinite…

Operator Algebras · Mathematics 2007-09-10 Karl-Hermann Neeb

In any semigroup $S$ satisfying the Strong Folner Condition, there are three natural notions of density for a subset $A$ of $S$: Folner density $d(A)$, Banach density $d^*(A)$, and translation density $d_t(A)$. If $S$ is commutative or left…

Combinatorics · Mathematics 2025-07-23 Daniel Glasscock , Neil Hindman , Dona Strauss

We display a symmetric monoidal equivalence between the stable $\infty$-category of filtered spectra, and quasi-coherent sheaves on $\mathbb{A}^1 / \mathbb{G}_m$, the quotient in the setting of spectral algebraic geometry, of the flat…

Algebraic Topology · Mathematics 2021-09-17 Tasos Moulinos

We present a novel perspective on the clustering of dark matter in phase space by defining the particle phase space average density ($P^2SAD$) as a two-dimensional extension of the two-point correlation function averaged within a certain…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-05 Jesus Zavala , Niayesh Afshordi

For each nonzero $h\in \mathbb{F}[x]$, where $\mathbb{F}$ is a field, let $\mathsf{A}_h$ be the unital associative algebra generated by elements $x,y$, satisfying the relation $yx-xy = h$. This gives a parametric family of subalgebras of…

Representation Theory · Mathematics 2019-03-05 Samuel A. Lopes , Andrea Solotar

We say that two classes of topological spaces are equivalent if each member of one class has a homeomorphic copy in the other class and vice versa. Usually when the Borel complexity of a class of metrizable compacta is considered, the class…

General Topology · Mathematics 2020-02-19 Adam Bartoš

Topological data analysis offers a rich source of valuable information to study vision problems. Yet, so far we lack a theoretically sound connection to popular kernel-based learning techniques, such as kernel SVMs or kernel PCA. In this…

Machine Learning · Statistics 2014-12-24 Jan Reininghaus , Stefan Huber , Ulrich Bauer , Roland Kwitt

We consider L-infinity quasi-isomorphisms for Hochschild cochains whose structure maps admit "graphical expansion". We introduce the notion of stable formality quasi-isomorphism which formalizes such an L-infinity quasi-isomorphism. We…

K-Theory and Homology · Mathematics 2019-12-13 Vasily Dolgushev

We report ALMA Band 6 continuum observations of 2000 AU resolution toward four massive molecular clouds in the Central Molecular Zone of the Galaxy. To study gas fragmentation, we use the dendrogram method to identify cores as traced by the…

Density-based clustering methodology has been widely considered in the statistical literature for classifying Euclidean observations. However, this approach has not been contemplated for directional data yet. In this work, directional…

Methodology · Statistics 2023-03-07 Paula Saavedra-Nieves , Martín Fernández-Pérez
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