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In this paper we prove Area theorem, Biebarbach`s Theorem, Koebe Quarter Theorem and Mergelyan`s Approximation Theorem in the bicomplex framework.

Functional Analysis · Mathematics 2023-06-06 Amjad Ali , Mohd Arif , Romesh Kumar

We provide a criterion for the existence of right approximations in cocomplete additive categories; it is a straightforward generalisation of a result due to El Bashir. This criterion is used to construct adjoint functors in homotopy…

Category Theory · Mathematics 2010-06-24 Henning Krause

We present a purely category-theoretic characterization of retracts of Fra\"iss\'e limits. For this aim, we consider a natural version of injectivity with respect to a pair of categories (a category and its subcategory). It turns out that…

Category Theory · Mathematics 2013-10-10 Wieslaw Kubiś

We present new induction principles for the syntax of dependent type theories, which we call relative induction principles. The result of the induction principle relative to a functor F into the syntax is stable over the codomain of F. We…

Logic in Computer Science · Computer Science 2021-07-20 Rafaël Bocquet , Ambrus Kaposi , Christian Sattler

We prove that a jointly conservative family of geometric functors between rigidly-compactly generated tensor triangulated categories induces a surjective map on Balmer spectra. From this we deduce a fiberwise criterion for Balmer's…

Category Theory · Mathematics 2024-09-27 Tobias Barthel , Natalia Castellana , Drew Heard , Beren Sanders

This note is intended to reformulate the Dixmier-Malliavin theorem about smooth group representations in the language of bornological vector spaces, instead of topological vector spaces. This language turns out to allow a more general…

Representation Theory · Mathematics 2020-01-17 Gal Dor

We study the model theory of vector spaces with a bilinear form over a fixed field. For finite fields this can be, and has been, done in the classical framework of full first-order logic. For infinite fields we need different logical…

Logic · Mathematics 2023-03-24 Mark Kamsma

Urysohn's Lemma is a crucial property of normal spaces that deals with separation of closed sets by continuous functions. It is also a fundamental ingredient in proving the Tietze Extension Theorem, another property of normal spaces that…

General Topology · Mathematics 2021-05-21 Florica C. Cîrstea

We clarify the relation between the `bosonisation' construction (due to the author) which can be used to turn a Hopf algebra $B$ in the category of $H$-modules or $H$-comodules into an equivalent ordinary Hopf algebra, and a version of…

q-alg · Mathematics 2008-02-03 S. Majid

The Schur orthogonality relations are a cornerstone in the representation theory of groups. We utilize a generalization to weak Hopf algebras to provide a new, readily verifiable condition on the skeletal data for deciding whether a given…

Quantum Algebra · Mathematics 2024-02-06 Jacob C. Bridgeman , Laurens Lootens , Frank Verstraete

Hurwitz spaces are moduli of isotopy classes of covers. A specific space is formed from a finite group G and C, r of its conjugacy classes and an equivalence relation \dagger. Components, interpret as a braid orbits on Nielsen classes.…

Algebraic Geometry · Mathematics 2025-09-12 Michael D. Fried

In this note, we provide an axiomatic framework that characterizes the stable $\infty$-categories that are module categories over a motivic spectrum. This is done by invoking Lurie's $\infty$-categorical version of the Barr--Beck theorem.…

Algebraic Geometry · Mathematics 2020-06-24 Elden Elmanto , Håkon Kolderup

We establish that a category of fibrant objects (in the sense of Brown) admits a Dwyer-Kan homotopical calculus of right fractions. This is done using a homotopical calculus of cocycles, which is an auxiliary structure that can be defined…

Category Theory · Mathematics 2015-09-29 Zhen Lin Low

A theory of allocation maps has been developed by J. F. Feinstein and M. J. Heath in order to prove a theorem, using Zorn's lemma, concerning the compact plane sets known as Swiss cheese sets. These sets are important since, as domains,…

Functional Analysis · Mathematics 2010-10-14 Jonathan Mason

We review three examples of functors from Lorentzian categories and their applications in finiteness results, singularity theorems and boundary constructions. The third example is a novel functor from the category of ordered measure spaces…

Differential Geometry · Mathematics 2023-02-22 Olaf Müller

In weighted Orlicz type spaces ${\mathcal S}_{_{\scriptstyle \mathbf p,\,\mu}}$ with a variable summation exponent, the direct and inverse approximation theorems are proved in terms of best approximations of functions and moduli of…

Classical Analysis and ODEs · Mathematics 2020-04-22 Fahreddin G. Abdullayev , Stanislav O. Chaichenko , Meerim Imash kyzy , Andrii L. Shidlich

We define a class of higher inductive types that can be constructed in the category of sets under the assumptions of Zermelo-Fraenkel set theory without the axiom of choice or the existence of uncountable regular cardinals. This class…

Logic · Mathematics 2022-02-07 Andrew Swan

Bowen's notion of sofic entropy is a powerful invariant for classifying probability-preserving actions of sofic groups. It can be defined in terms of the covering numbers of certain metric spaces associated to such an action, the `model…

Dynamical Systems · Mathematics 2016-06-07 Tim Austin

We define a diffeology on the Milnor classifying space of a diffeological group $G$, constructed in a similar fashion to the topological version using an infinite join. Besides obtaining the expected classification theorem for smooth…

Geometric Topology · Mathematics 2017-10-31 Jean-Pierre Magnot , Jordan Watts

We define A-infinity-bimodules similarly to Tradler and show that this notion is equivalent to an A-infinity-functor with two arguments which takes values in the differential graded category of complexes of k-modules, where k is a ground…

Category Theory · Mathematics 2008-02-15 Volodymyr Lyubashenko , Oleksandr Manzyuk