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Counterfactual Explanations are becoming a de-facto standard in post-hoc interpretable machine learning. For a given classifier and an instance classified in an undesired class, its counterfactual explanation corresponds to small…

Machine Learning · Computer Science 2024-01-17 Veronica Piccialli , Dolores Romero Morales , Cecilia Salvatore

In this paper, we will give a natural definition for morphisms between multiplicative unitaries. We will then discuss some equivalences of this definition and some interesting properties of them. Moreover, we will define normal…

funct-an · Mathematics 2008-02-03 Chi-Keung Ng

We introduce the notions of a mutually algebraic structures and theories and prove many equivalents. A theory $T$ is mutually algebraic if and only if it is weakly minimal and trivial if and only if no model $M$ of $T$ has an expansion…

Logic · Mathematics 2012-07-25 Michael C. Laskowski

We illustrate the generative power of the lifting property (orthogonality of morphisms in a category) as means of defining natural elementary mathematical concepts by giving a number of examples in various categories, in particular showing…

Category Theory · Mathematics 2017-07-21 Misha Gavrilovich

We prove from suitable large cardinal hypotheses that the least weakly compact cardinal can be unfoldable, weakly measurable and even nearly $\theta$-supercompact, for any desired $\theta$. In addition, we prove several global results…

Logic · Mathematics 2013-05-28 Brent Cody , Moti Gitik , Joel David Hamkins , Jason Schanker

We give an upper bound for the norm of the determinant of additively indecomposable, totally positive definite quadratic forms defined over the ring of integers of totally real number fields. We apply these results to find lower and upper…

Number Theory · Mathematics 2025-10-10 Magdaléna Tinková , Pavlo Yatsyna

The ultrapower theorem of Keisler-Shelah allows such model-theoretic notions as elementary equivalence, elementary embedding and existential embedding to be couched in the language of categories (limits, morphism diagrams). This in turn…

Logic · Mathematics 2008-02-03 Paul Bankston

We construct a new class of affine complements ${\mathbb P}^M\setminus S$ with the trivial group of automorphisms, where $S\subset {\mathbb P}^M$ is a rational hypersurface, $M$ is odd and $M\geqslant 5$.

Algebraic Geometry · Mathematics 2025-10-21 Aleksandr V. Pukhlikov

A class of two-dimensional superintegrable systems on a constant curvature surface is considered as the natural generalization of some well known one-dimensional factorized systems. By using standard methods to find the shape-invariant…

Mathematical Physics · Physics 2009-11-11 J. A. Calzada , J. Negro , M. A. del Olmo

We exhibit a simple condition under which a finite involutary semigroup whose semigroup reduct is inherently nonfinitely based is also inherently nonfinitely based as a unary semigroup. As applications, we get already known as well as new…

Group Theory · Mathematics 2014-11-25 Karl Auinger , Igor Dolinka , Tatiana V. Pervukhina , Mikhail V. Volkov

We introduce the notion of extended affine Lie superalgebras and investigate the properties of their root systems. Extended affine Lie algebras, invariant affine reflection algebras, finite dimensional basic classical simple Lie…

Quantum Algebra · Mathematics 2015-02-13 Malihe Yousofzadeh

We present a classification theorem for a class of unital simple separable amenable ${\cal Z}$-stable $C^*$-algebras by the Elliott invariant. This class of simple $C^*$-algebras exhausts all possible Elliott invariant for unital stably…

Operator Algebras · Mathematics 2015-11-17 Guihua Gong , Huaxin Lin , Zhuang Niu

For each countable ordinal $\alpha$, we introduce an ideal $conv_\alpha$ and use it to characterize the class of all compact countable spaces which are homeomorphic to the space $\omega^{\alpha}\cdot n+1$ with the order topology. The…

General Topology · Mathematics 2025-03-18 Rafał Filipów , Małgorzata Kowalczuk , Adam Kwela

A definition of summability is put forward in the framework of general Carleman ultraholomorphic classes in sectors, so generalizing $k-$summability theory as developed by J.-P. Ramis. Departing from a strongly regular sequence of positive…

Complex Variables · Mathematics 2014-02-10 Alberto Lastra , Stephane Malek , Javier Sanz

A new pair of asymptotic invariants for finitely presented groups, called intrinsic and extrinsic tame filling functions, are introduced. These filling functions are quasi-isometry invariants that strengthen the notions of intrinsic and…

Group Theory · Mathematics 2014-10-13 Mark Brittenham , Susan Hermiller

We classify essential algebras whose irredundant non-refinable covers consist of primal algebras. The proof is obtained by constructing one to one correspondence between such algebras and partial orders on finite sets. Further, we prove…

Logic · Mathematics 2014-06-26 Shohei Izawa

We describe an easy way how to find supercharacter theories for a finite group, if its character table is known. Namely, we show how an arbitrary partition of the conjugacy classes or of the irreducible characters can be refined to the…

Representation Theory · Mathematics 2023-03-20 Frieder Ladisch

We consider the problem of determining whether a monomial ideal is dominant. This property is critical for determining for which monomial ideals the Taylor resolution is minimal. We first analyze dominant ideals with a fixed least common…

We define and study the class of inner ultrahomogeneous groups, which includes Hall's universal group and the universal locally recursively presentable group. We provide simple criteria for ample generic automorphisms, straight maximality,…

Logic · Mathematics 2024-05-31 Tomasz Rzepecki

The geometric and algebraic theory of monomial ideals and multigraded modules is initiated over real-exponent polynomial rings and, more generally, monoid algebras for real polyhedral cones. The main results include the generalization of…

Commutative Algebra · Mathematics 2025-11-11 Ezra Miller