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Related papers: Koopman operators and the $3x+1$-dynamical system

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Paul Erdos claimed that mathematics is not yet ready to settle the 3x+1 conjecture. I agree, but very soon it will be! With the exponential growth of computer-generated mathematics, we (or rather our silicon brethrern) would have a shot at…

Combinatorics · Mathematics 2009-03-25 Doron Zeilberger

The study of the Two-Body and Circular Restricted Three-Body Problems in the field of aerospace engineering and sciences is deeply important because they help describe the motion of both celestial and artificial satellites. With the growing…

Mathematical Physics · Physics 2025-04-17 George Nehma , Madhur Tiwari , Manasvi Lingam

The 3x+ 1 problem concerns iteration of the map on the integers given by T(n) = (3n+1)/2 if n is odd; T(n) = n/2 if n is even. The 3x+1 Conjecture asserts that for every positive integer n > 1 the forward orbit of n under iteration by T…

Number Theory · Mathematics 2011-01-12 Jeffrey C. Lagarias

In this paper, we introduce and develop the theory of the Collatz process and the method of dynamical balls. We leverage this theory to study the Collatz conjecture. This theory also has a subtle connection with the infamous problem of the…

General Mathematics · Mathematics 2026-03-10 Theophilus Agama

The Koopman operator lifts nonlinear dynamical systems into a functional space of observables, where the dynamics are linear. In this paper, we provide three different Koopman representations for hybrid systems. The first is specific to…

Dynamical Systems · Mathematics 2020-06-23 Craig Bakker , Arnab Bhattacharya , Samrat Chatterjee , Casey J. Perkins , Matthew R. Oster

The study of mathematical connections between operator-theoretic formulations of classical dynamics and quantum mechanics began at least as early as the 1930s in work of Koopman and von Neumann and was developed in later decades by many…

Dynamical Systems · Mathematics 2026-03-23 Dimitrios Giannakis , Michael Montgomery

This paper gives a simple proof of the Wirsching-Goodwin representation of integers connected to 1 in the $3x+1$ problem (see \cite{Wirsching} and \cite{Goodwin}). This representation permits to compute all the ascending Collatz sequences…

Number Theory · Mathematics 2018-06-01 Jean-Jacques Daudin , Laurent Pierre

The 3x+1 problem is one of the most classical problems in computer science, related to many fields. As it is thought by scientists a highly hard problem, resolving it successfully not only can improve the research in many relating fields,…

Discrete Mathematics · Computer Science 2012-05-07 Lizhi Du

A majority of methods from dynamical systems analysis, especially those in applied settings, rely on Poincar\'e's geometric picture that focuses on "dynamics of states". While this picture has fueled our field for a century, it has shown…

Dynamical Systems · Mathematics 2013-01-01 Marko Budišić , Ryan M. Mohr , Igor Mezić

We develop a Koopman operator framework for studying the {computational properties} of dynamical systems. Specifically, we show that the resolvent of the Koopman operator provides a natural abstraction of halting, yielding a ``Koopman…

Mathematical Physics · Physics 2025-10-08 Francesco Caravelli , Jean-Charles Delvenne

The design and analysis of optimal control policies for dynamical systems can be complicated by nonlinear dependence in the state variables. Koopman operators have been used to simplify the analysis of dynamical systems by mapping the flow…

Dynamical Systems · Mathematics 2019-08-07 Craig Bakker , Steven Rosenthal , Kathleen E. Nowak

This paper studies certain trajectories of the Collatz function. I show that if for each odd number $n$, $n\sim 3n+2$ then every positive integer $n \in \mathbb{N}\setminus 2^{\mathbb{N}}$ has the representation…

History and Overview · Mathematics 2020-05-19 Roy Burson

Koopman operator theory has been successfully applied to problems from various research areas such as fluid dynamics, molecular dynamics, climate science, engineering, and biology. Applications include detecting metastable or coherent sets,…

Quantum Physics · Physics 2022-07-13 Stefan Klus , Feliks Nüske , Sebastian Peitz

In this paper, we propose a Koopman operator based approach to describe the nonlinear dynamics of a quadrotor on SE(3) in terms of an infinite-dimensional linear system which evolves in the space of observable functions (lifted space) and…

Systems and Control · Electrical Eng. & Systems 2021-06-10 Vrushabh Zinage , Efstathios Bakolas

Research on Koopman operator theory has focused on three key areas for several decades: the mathematical structure of the Koopman eigenfunction space, the basis of this space, and the ability to represent nonlinear dynamics as linear. This…

Dynamical Systems · Mathematics 2023-06-13 Ido Cohen , Eli Appleboim

I want to show one possibility to proof the Collatz conjecture, also called 3n+1 conjecture, for any natural number N. For this, I limit my analysis on the direct odd follower of every natural odd number and show the connections between the…

General Mathematics · Mathematics 2013-03-14 Carolin Zöbelein

Exploring the Collatz Conjecture and changing the expression from 3n + 1 to 5n + 1, we found patterns in different sets of numbers. Some numbers reduce to one (as stated in the Collatz Conjecture), some might escape to infinity, and some…

Number Theory · Mathematics 2023-05-03 Shouvik Ahmed Antu , Raina Shrimali , Miranda Jones

The infamous 3x+1 conjecture spread by Lothar Collatz in 1952, despite its elementary formulation, remained unproved for over 60 years. From the heuristical probabilistic approach to the complex mapping of the algorithm, the scientific…

General Mathematics · Mathematics 2018-02-15 Nicolas Mallet

The 3x+1 problem concerns iteration of the map T(n) =(3n+1)/2 if n odd; n/2 if n even. The 3x +1 Conjecture asserts that for every positive integer n>1 the forward orbit of n includes the integer 1. This paper is an annotated bibliography…

Number Theory · Mathematics 2012-02-14 Jeffrey C. Lagarias

Let $q$ be an odd prime, and let $T_{q}:\mathbb{Z}\rightarrow\mathbb{Z}$ be the Shortened $qx+1$ map, defined by $T_{q}\left(n\right)=n/2$ if $n$ is even and $T_{q}\left(n\right)=\left(qn+1\right)/2$ if $n$ is odd. The study of the dynamics…

Dynamical Systems · Mathematics 2024-10-18 Maxwell Charles Siegel