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We consider a dynamic inverse problem for a dynamical system which describes the propagation of waves in a Krein string. The problem is reduced to an integral equation and an important special case is considered when the string density is…

Analysis of PDEs · Mathematics 2025-05-27 A. S. Mikhaylov , V. S. Mikhaylov

We study the dynamics of pairs of connected masses in the plane, when nonholonomic (knife-edge) constraints are realized by forces of viscous friction, in particular its relation to constrained dynamics, and its approximation by the method…

Classical Physics · Physics 2017-05-19 Sergiy Koshkin , Vojin Jovanovic

We investigate some classical aspects of fundamental strings via numerical experiments. In particular, we study the thermodynamics of a string network within a toroidal universe, as a function of string energy density and space…

High Energy Physics - Theory · Physics 2009-10-28 Mairi Sakellariadou

We define string geometry: spaces of superstrings including the interactions, their topologies, charts, and metrics. Trajectories in asymptotic processes on a space of strings reproduce the right moduli space of the super Riemann surfaces…

High Energy Physics - Theory · Physics 2021-02-03 Matsuo Sato

A high fidelity model is developed for an elastic string pendulum, one end of which is attached to a rigid body while the other end is attached to an inertially fixed reel mechanism which allows the unstretched length of the string to be…

Dynamical Systems · Mathematics 2009-09-14 Taeyoung Lee , Melvin Leok , N. Harris McClamroch

(abbreviated) In this paper we develop a consistent WKBJ formalism, together with a formal first order perturbation theory for calculating the properties of the inertial modes of a uniformly rotating coreless body (modelled as a polytrope…

Solar and Stellar Astrophysics · Physics 2015-05-19 P. B. Ivanov , J. C. B. Papaloizou

This paper discusses aspects of the second order hyperbolic partial differential equation associated with the ideal lossless string under tension and it's relationship to two discrete models. These models are finite differencing in the time…

Computational Physics · Physics 2007-05-23 Georg Essl

We consider classical and quantum strings in the conformally invariant background corresponding to the SL(2,R) WZWN model. This background is locally anti-de Sitter spacetime with non-vanishing torsion. Conformal invariance is expressed as…

High Energy Physics - Theory · Physics 2016-09-06 H. J. de Vega , A. L. Larsen , N. Sánchez

We study eigenvibrations for inhomogeneous string consisting of two parts with strongly contrasting stiffness and mass density. In this work we treat a critical case for the high frequency approximations, namely the case when the order of…

Spectral Theory · Mathematics 2013-09-03 Natalia Babych , Yuri Golovaty

A strong-weak coupling duality symmetry of the string equations of motion has been suggested in the literature. This symmetry implies that vacua occur in pairs. Since the coupling constant is a dynamical variable in string theory, tunneling…

High Energy Physics - Theory · Physics 2011-06-10 J. D. Cohn , Vipul Periwal

This is a short review on strings in curved spacetimes. We start by recalling the classical and quantum string behaviour in singular plane waves backgrounds. We then report on the string behaviour in cosmological spacetimes (FRW, de Sitter,…

High Energy Physics - Theory · Physics 2007-05-23 H. J. de Vega

A full quantum description of global vortex strings is presented in the framework of a pure Higgs system with a broken global U(1) symmetry in 3+1D. An explicit expression for the string creation operator is obtained, both in terms of the…

High Energy Physics - Theory · Physics 2009-10-31 H. Fort , E. Marino

In these lectures, we provide an introduction to the complex WKB method, using as a guiding example a class of anharmonic oscillators that appears in the ODE/IM correspondence. In the first three lectures, we introduce the main objects of…

Mathematical Physics · Physics 2025-01-14 Gabriele Degano , Davide Masoero

An experimental analysis of the vortex-induced vibrations of a hanging string with variable tension along its length is presented in this paper. It is shown that standing waves develop along the hanging string. The evolution of the Strouhal…

Two new effects of interaction of the gauge string with a homogeneous density of fermions are considered in a gauge model with an anomalous coupling of vector fields with fermions. First, the presence of an induced nonzero magnetic-like…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. A. Kozhevnikov

We study the small vibrations of an axially travelling string with a dashpoint damping at one end. The string is modelled by a wave equation in a time-dependent interval with two endpoints moving at a constant speed $v$. For the undamped…

Analysis of PDEs · Mathematics 2023-04-11 Seyf Eddine Ghenimi , Abdelmouhcene Sengouga

We study dynamics of triple junction of (p,q) strings in Type IIB string theory. We probe tension and mass density of (p,q) strings by studying harmonic fluctuations of the triple junction. We show that they agree perfectly with BPS formula…

High Energy Physics - Theory · Physics 2009-10-30 Soo-Jong Rey , Jung-Tay Yee

Perturbative string amplitudes are correctly derived from the string geometry theory, which is one of the candidates of a non-perturbative formulation of string theory. In order to derive non-perturbative effects rather easily, we formulate…

High Energy Physics - Theory · Physics 2020-10-15 Matsuo Sato , Yuji Sugimoto

We study the perturbative dynamics of an infinite gravitating Nambu-Goto string within the general-relativistic perturbation framework. We develop the gauge invariant metric perturbation on a spacetime containing a self-gravitating straight…

General Relativity and Quantum Cosmology · Physics 2009-12-30 Kouji Nakamura , Akihiro Ishibashi , Hideki Ishihara

String vibration represents an active field of research in acoustics. Small-amplitude vibration is often assumed, leading to simplified physical models that can be simulated efficiently. However, the inclusion of nonlinear phenomena due to…

Numerical Analysis · Mathematics 2022-06-08 Michele Ducceschi , Stefan Bilbao