English
Related papers

Related papers: Maximal Hardy Fields

200 papers

We show that all maximal Hardy fields are elementarily equivalent as differential fields to the differential field $\mathbb T$ of transseries, and give various applications of this result and its proof.

Logic · Mathematics 2024-08-13 Matthias Aschenbrenner , Lou van den Dries , Joris van der Hoeven

We study relative differential closure in the context of Hardy fields. Using our earlier work on algebraic differential equations over Hardy fields, this leads to a proof of a conjecture of Boshernitzan (1981): the intersection of all…

Logic · Mathematics 2026-04-27 Matthias Aschenbrenner , Lou van den Dries , Joris van der Hoeven

We discuss the conjecture that every maximal Hardy field has the Intermediate Value Property for differential polynomials, and its equivalence to the statement that all maximal Hardy field are elementarily equivalent to the differential…

Logic · Mathematics 2019-04-03 Matthias Aschenbrenner , Lou van den Dries , Joris van der Hoeven

We show that every Hardy field extends to an $\omega$-free Hardy field. This result relates to classical oscillation criteria for second-order homogeneous linear differential equations. It is essential in [10], and here we apply it to…

Commutative Algebra · Mathematics 2026-03-11 Matthias Aschenbrenner , Lou van den Dries , Joris van der Hoeven

We show how to fill "countable" gaps in Hardy fields. We use this to prove that any two maximal Hardy fields are back-and-forth equivalent.

Logic · Mathematics 2024-06-19 Matthias Aschenbrenner , Lou van den Dries , Joris van der Hoeven

We show that maximal analytic Hardy fields are $\eta_1$ in the sense of Hausdorff. We also prove various embedding theorems about analytic Hardy fields. For example, the ordered differential field $\mathbb T$ of transseries is shown to be…

Logic · Mathematics 2025-09-16 Matthias Aschenbrenner , Lou van den Dries

We define the universal exponential extension of an algebraically closed differential field and investigate its properties in the presence of a nice valuation and in connection with linear differential equations. Next we prove normalization…

Commutative Algebra · Mathematics 2026-04-28 Matthias Aschenbrenner , Lou van den Dries , Joris van der Hoeven

We show that asymptotic (valued differential) fields have unique maximal immediate extensions. Connecting this to differential-henselianity, we prove that any differential-henselian asymptotic field is differential-algebraically maximal,…

Commutative Algebra · Mathematics 2020-12-09 Nigel Pynn-Coates

We establish magnetic improvements upon the classical Hardy inequality for two specific choices of singular magnetic fields. First, we consider the Aharonov-Bohm field in all dimensions and establish a sharp Hardy-type inequality that takes…

Spectral Theory · Mathematics 2020-08-28 Luca Fanelli , David Krejcirik , Ari Laptev , Luis Vega

We show that every valued differential field has an immediate strict extension that is spherically complete. We also discuss the issue of uniqueness up to isomorphism of such an extension.

Commutative Algebra · Mathematics 2018-04-18 Matthias Aschenbrenner , Lou van den Dries , Joris van der Hoeven

In this paper we prove three differenttypes of the so-called many-particle Hardy inequalities. One of them is a "classical type" which is valid in any dimesnion $d\neq 2$. The second type deals with two-dimensional magnetic Dirichlet forms…

Analysis of PDEs · Mathematics 2014-02-26 M. Hoffmann-Ostenhof , T. Hoffmann-Ostenhof , A. Laptev , J. Tidblom

We introduce the notion of differential largeness for fields equipped with several commuting derivations (as an analogue to largeness of fields). We lay out the foundations of this new class of "tame" differential fields. We state several…

Algebraic Geometry · Mathematics 2024-02-07 Omar León Sánchez , Marcus Tressl

In this paper we prove sharp Hardy inequalities by using Maximal function theory. Our results improve and extend the well-known results of G.Hardy \cite{Ha04}, T.Cazenave \cite {Ca03}, J.-Y.Chemin\cite {Ch06} and T.Tao\cite {TT06}.

Analysis of PDEs · Mathematics 2007-05-23 Jia Yuan , Junyong Zhang

We prove an equivalence result between the validity of a pointwise Hardy inequality in a domain and uniform capacity density of the complement. This result is new even in Euclidean spaces, but our methods apply in general metric spaces as…

Analysis of PDEs · Mathematics 2026-03-19 Riikka Korte , Juha Lehrbäck , Heli Tuominen

Fields with only finitely many maximal subrings are completely determined. We show that such fields are certain absolutely algebraic fields and give some characterization of them. In particular, we show that the following conditions are…

Commutative Algebra · Mathematics 2014-12-17 Alborz Azarang

We deal with Dirac operators with external homogeneous magnetic fields. Hardy-type inequalities related to these operators are investigated: for a suitable class of transversal magnetic fields, we prove a Hardy inequality with the same best…

Mathematical Physics · Physics 2016-03-24 Luca Fanelli , Luis Vega , Nicola Visciglia

We prove that the extremal sequences for the Bellman function of the dyadic maximal operator behave approximately as eigenfunctions of this operator for a specific eigenvalue. We use this result to prove the analogous one with respect to…

Functional Analysis · Mathematics 2019-10-15 Eleftherios Nikolidakis

We prove a sharp integral inequality which connects the dyadic maximal operator with the Hardy operator. We also give some applications of this inequality.

Functional Analysis · Mathematics 2012-10-25 Eleftherios Nikolidakis

Differentially algebraic Hardy field extensions of short Hardy fields are short. This is proved in the more general setting of $H$-fields. As an application we extend a theorem of Rosenlicht (1981) by showing that each short asymptotic…

Logic · Mathematics 2025-08-11 Matthias Aschenbrenner , Lou van den Dries

New Hardy type inequalities in sectorial area and as a limit in an exterior of a ball are proved. Sharpness of the inequalities is shown as well.

Analysis of PDEs · Mathematics 2021-03-17 Nikolai Kutev , Tsviatko Rangelov
‹ Prev 1 2 3 10 Next ›