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In this paper, we prove that almost resolvable $k$-cycle systems (briefly $k$-ARCS) of $(K_u \times K_g)(\lambda)$ exists for all $k \equiv 0(mod \ 4) $ with few possible exceptions, where $\times$ represents tensor product of graphs.

Combinatorics · Mathematics 2022-06-22 S. Duraimurugan , A. Shanmuga Vadivu , A. Muthusamy

We show that some spectral properties of the almost Mathieu operator with frequency well approximated by rationals can be as poor as at all possible in the class of all one-dimensional discrete Schroedinger operators. For the class of…

Mathematical Physics · Physics 2023-03-31 Artur Avila , Yoram Last , Mira Shamis , Qi Zhou

We develop a new KAM scheme that applies to SL(2,R) cocycles with one frequency, irrespective of any Diophantine condition on the base dynamics. It gives a generalization of Dinaburg-Sinai's Theorem to arbitrary frequencies: under a…

Dynamical Systems · Mathematics 2010-01-19 Artur Avila , Bassam Fayad , Raphael Krikorian

This paper addresses the Cauchy problem for the cubic defocusing nonlinear Schr\"odinger equation (NLS) with almost periodic initial data. We prove that for small analytic quasiperiodic initial data satisfying Diophantine frequency…

Analysis of PDEs · Mathematics 2025-08-05 Jake Fillman , Long Li , Milivoje Lukić , Qi Zhou

We introduce a unitary almost-Mathieu operator, which is obtained from a two-dimensional quantum walk in a uniform magnetic field. We exhibit a version of Aubry--Andr\'{e} duality for this model, which partitions the parameter space into…

Spectral Theory · Mathematics 2024-10-08 Christopher Cedzich , Jake Fillman , Darren C. Ong

The approximation properties of the Aldaz-Kounchev-Render (AKR) operators are discussed and classes of functions for which these operators approximate better than the classical Bernstein operators are described. The new results are then…

Numerical Analysis · Mathematics 2022-04-25 Ana Acu , Stefano De Marchi , Ioan Rasa

Introducing and studying the pattern frequency algebra, we prove the analogue of L\"uck's approximation theorems on $L^2$-spectral invariants in the case of aperiodic order. These results imply a uniform convergence theorem for the…

Functional Analysis · Mathematics 2007-05-23 Gábor Elek

We consider discrete one-dimensional random Schroedinger operators with decaying matrix-valued, independent potentials. We show that if the l^2-norm of this potential has finite expectation value with respect to the product measure then…

Mathematical Physics · Physics 2015-05-14 Richard Froese , David Hasler , Wolfgang Spitzer

We study the spectral properties of ergodic Schr\"{o}dinger operators that are associated to a certain family of non-primitive substitutions on a binary alphabet. The corresponding subshifts provide examples of dynamical systems that go…

Mathematical Physics · Physics 2021-05-12 Benjamin Eichinger , Philipp Gohlke

Periodic approximations of quasicrystals are a powerful tool in analyzing spectra of Schr\"odinger operators arising from quasicrystals, given the known theory for periodic crystals. Namely, we seek periodic operators whose spectra…

Dynamical Systems · Mathematics 2024-08-20 Lior Tenenbaum

Rice's theorem shows that nontrivial extensional properties of partial recursive functions are undecidable. For finite weighted Boolean optimization/CSP-style slices, a Rice-style structural analogue holds for tractability classification:…

Computational Complexity · Computer Science 2026-05-28 Tristan Simas

The arithmetics of the frequency and of the rotation number play a fundamental role in the study of reducibility of analytic quasi-periodic cocycles which are sufficiently close to a constant. In this paper we show how to generalize…

Dynamical Systems · Mathematics 2011-11-24 Claire Chavaudret , Stefano Marmi

We establish sharp results on the modulus of continuity of the distribution of the spectral measure for one-frequency Schrodinger operators with Diophantine frequencies in the region of absolutely continuous spectrum. More precisely, we…

Dynamical Systems · Mathematics 2015-05-14 Artur Avila , Svetlana Jitomirskaya

The spectral analysis of discretized one-dimensional Schr\"{o}dinger operators is a very difficult problem which has been studied by numerous mathematicians. A natural problem at the interface of numerical analysis and operator theory is…

Numerical Analysis · Mathematics 2025-10-20 Nathanial P. Brown

A partial answer on [KS2, Question 2] is given. Namely, an operator $R$ similar to a quasianalytic contraction whose quasianalytic spectral set is equal to its spectrum and is a proper subarc of the unit circle is constructed, but no…

Functional Analysis · Mathematics 2022-12-06 Maria F. Gamal'

We investigate an almost sure limit theorem (ASCLT) for sequences of random variables having the form of a ratio of two terms such that the numerator satisfies the ASCLT and the denominator is a positive term which converges almost surely…

Probability · Mathematics 2012-09-04 Peggy Cénac , Khalifa Es-Sebaiy

We prove a conjecture of Kurdyka stating that every arc-symmetric semialgebraic set is precisely the zero locus of an arc-analytic semialgebraic function. This implies, in particular, that arc-symmetric semialgebraic sets are in one-to-one…

Algebraic Geometry · Mathematics 2017-09-29 Janusz Adamus , Hadi Seyedinejad

Let p=tp(a/A) be a stationary type in an arbitrary finite rank stable theory, and P an A-invariant family of partial types. The following property is introduced and characterised: whenever c is definable over (A,a) and a is not algebraic…

Logic · Mathematics 2013-12-19 Rahim Moosa , Anand Pillay

We prove a number of results on the \'etale cohomology of rigid analytic varieties over $p$-adic non-archimedean local fields. Among other things, we establish bounds for Frobenius eigenvalues, show a strong version of Grothendieck's local…

Algebraic Geometry · Mathematics 2025-07-21 David Hansen , Bogdan Zavyalov

We obtain a quenched vector-valued almost sure invariance principle (ASIP) for random expanding on average cocycles. This is achieved by combining the adapted version of Gou\"{e}zel's approach for establishing ASIP and the recent…

Dynamical Systems · Mathematics 2023-01-05 Davor Dragičević , Yeor Hafouta , Julien Sedro