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Let $(X,\dist)$ be a complete metric space and let $C\subseteq X$ be a closed invariant set. We study fixed points of maps $T\colon C\to C$ governed by a \emph{verifiable} contractive modulus. The modulus is encoded by a contractive gauge…

Dynamical Systems · Mathematics 2026-02-10 Chandrasekhar Gokavarapu , Srinivasulu Ch , D V N S Sriram Murthy , Rajeev Muthu

In this paper we explore the representation property over sets. This property generalizes constructibility, however is weak enough to enable us to prove that the class of theories $T$ whose models are representable is exactly the class of…

Logic · Mathematics 2009-06-18 Moran Cohen , Saharon Shelah

A new class of semi-implicit numerical schemes for linear advection equation on Cartesian grids is derived that is inspired by so-called $\kappa$-schemes used with fully explicit discretizations for this type of problems. Opposite to fully…

Numerical Analysis · Mathematics 2016-11-15 Peter Frolkovič , Karol Mikula

Suppose t = (T,T_1, p) is a triple of two theories T subset T_1 in vocabularies tau subset tau_1 (respectively) of cardinality lambda and a tau_1-type p over the empty set; in the main case here is with T stable. We show the Hanf number for…

Logic · Mathematics 2019-02-07 Saharon Shelah

We introduce an axiomatisation of when a model of the form $L(V_{\kappa+1})^M$ can be considered a ``$\kappa$-Solovay model''; we show a characterisation of $\kappa$-Solovay models; and we prove elementary equivalences between…

Logic · Mathematics 2026-04-24 Cesare Straffelini , Sebastiano Thei

The paper deals with two issues: the existence of universal models of a theory T and related properties when cardinal arithmetic does not give this existence offhand. In the first section we prove that simple theories (e.g., theories…

Logic · Mathematics 2008-02-03 Saharon Shelah

Let $G$ be an arbitrary (not necessarily isomorphic to a closed subgroup of $\mathrm{GL}(r,\mathbb{C})$) complex Lie group, $U$ a complex manifold and $p:P\to U$ a $\mathcal{C}^\infty$ principal $G$-bundle on $U$. We introduce and study the…

Complex Variables · Mathematics 2023-12-14 Andrei Teleman

For any $Q\in\{\frac{3}{2},2,\frac{5}{2},3,\dotsc\}$, we establish a structure theory for the class $\mathcal{S}_Q$ of stable codimension 1 stationary integral varifolds admitting no classical singularities of density $<Q$. This theory…

Differential Geometry · Mathematics 2023-10-06 Paul Minter , Neshan Wickramasekera

In this paper we study the longstanding conjecture of whether there exists a noninner automorphism of order $p$ for a finite non-abelian $p$-group. We prove that if $G$ is a finite non-abelian $p$-group such that $G/Z(G)$ is powerful then…

Group Theory · Mathematics 2009-11-13 Alireza Abdollahi

The thermal conductivity, $\kappa$, of the heavy fermion superconductor UPt$_3$ was measured down to T$_c$/10. The absence of a linear term in the temperature dependence as T$\rightarrow$0 strongly suggests there are no zero energy…

Condensed Matter · Physics 2008-02-03 Benoit Lussier , Brett Ellman , Louis Taillefer

New fixed point results are presented for ${\cal U}_c^{\kappa}(X,X)$ maps in extension type spaces.

Classical Analysis and ODEs · Mathematics 2007-05-23 Ravi P Agarwal , Jong Kyu Kim , Donal O'Regan

We give a full solution to the question of existence of indiscernibles in dependent theories by proving the following theorem: for every $\theta$ there is a dependent theory $T$ of size $\theta$ such that for all $\kappa$ and $\delta$,…

Logic · Mathematics 2013-08-29 Itay Kaplan , Saharon Shelah

We prove an asymptotic saturation-type version of Rota's basis conjecture. It relies on the connection of Tao's slice rank with unstable tensors from geometric invariant theory.

Combinatorics · Mathematics 2021-07-28 Damir Yeliussizov

Models of dependent type theories are contextual categories with some additional structure. We prove that if a theory $T$ has enough structure, then the category $T\text{-}\mathbf{Mod}$ of its models carries the structure of a model…

Category Theory · Mathematics 2016-07-26 Valery Isaev

We develop the theory of generically stable types, independence relation based on nonforking and stable weight in the context of dependent (NIP) theories.

Logic · Mathematics 2008-02-01 Alexander Usvyatsov

Given a regular cardinal $\kappa$ such that $\kappa^{<\kappa}=\kappa$, we study a class of toposes with enough points, the $\kappa$-separable toposes. These are equivalent to sheaf toposes over a site with $\kappa$-small limits that has at…

Logic · Mathematics 2017-09-08 Christian Espíndola

A first-order theory T has the Schr\"oder-Bernstein (SB) property if any pair of elementarily bi-embeddable models are isomorphic. We prove that T has an expansion by constants that has the SB property if and only if T is superstable and…

Logic · Mathematics 2012-04-17 John Goodrick , Michael C. Laskowski

We use homotopy theory to extend the notion of strong and weak topological insulators to the non-stable regime (low numbers of occupied/empty energy bands). We show that for strong topological insulators in d spatial dimensions to be "truly…

Other Condensed Matter · Physics 2015-07-01 Ricardo Kennedy , Charles Guggenheim

Continuing our investigation into the Hierarchical Reference Theory of fluids for thermodynamic states of infinite isothermal compressibility kappa[T] we now turn to the available numerical evidence to elucidate the character of the partial…

Statistical Mechanics · Physics 2007-05-23 Albert Reiner , Gerhard Kahl

This paper focuses on using the first curvature $\kappa(t)$ of trajectory to describe the stability of linear time-invariant system. We extend the results for two and three-dimensional systems [Y. Wang, H. Sun, Y. Song et al.,…

Optimization and Control · Mathematics 2018-12-19 Yuxin Wang , Huafei Sun , Shoudong Huang , Yang Song