Article
Astronomy & Astrophysics
Francisco D. Mazzitelli, Leonardo G. Trombetta
Summary: This paper investigates the impact of stochastic fluctuations of the gravitational coupling G on the evolution of binary systems. Working at the elementary level in the Newtonian limit, the focus is mainly on laser ranging. The study demonstrates that observational data can be used to constrain the stochastic fluctuations and reanalyzes previous results on the implications of G fluctuations on cosmological models.
Article
Astronomy & Astrophysics
Le-Chen Qu, Jing Chen, Yu-Xiao Liu
Summary: We investigate the circuit complexity and Loschmidt echo for the (inverted) harmonic oscillators using a perturbative approach. Analytical results for the Lyapunov exponent and scrambling time of the inverted harmonic oscillators are derived. Our findings show that the circuit complexity and Loschmidt echo exhibit qualitatively similar behaviors, particularly with respect to the consistent Lyapunov exponent.
Article
Physics, Multidisciplinary
Anupam Kundu
Summary: We study transport in a one-dimensional lattice system with conserved quantities of 'volume' and energy. By considering a slowly evolving local equilibrium state, we estimate the correction to the local equilibrium distribution caused by space-time correlations of local currents. In the continuum limit, we derive drift-diffusion equation for 'volume' and super-diffusion equation for energy, showing a crossover from diffusive to anomalous transport.
Article
Mathematics, Applied
Juan-Carlos Felipe-Navarro
Summary: In this work, we prove the uniqueness and nondegeneracy of solutions to the nonlocal linear equation in the presence of a positive or odd solution, by utilizing a nonlocal Liouville-type method. This is the first work to establish such results in the nonlocal framework without using the Caffarelli-Silvestre extension technique.
CALCULUS OF VARIATIONS AND PARTIAL DIFFERENTIAL EQUATIONS
(2021)
Article
Mathematics, Interdisciplinary Applications
Maria V. Demina
Summary: We investigate the Liouvillian integrability of nondegenerate polynomial Levinson-Smith differential equations near infinity, providing both necessary and sufficient conditions. These equations generalize Lienard equations and are used for describing self-sustained oscillations. Our results are applicable to arbitrary degrees of the polynomials involved. We discover several new Liouvillian integrable subfamilies. For nondegenerate or algebraically degenerate near infinity polynomial Levinson-Smith equations, an upper bound is derived for the degrees of irreducible Darboux polynomials. We also perform a complete classification of Liouvillian first integrals for the cubic Levinson-Smith equation known as the nondegenerate or algebraically degenerate near infinity Rayleigh-Duffing-van der Pol equation.
INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS
(2023)
Article
Physics, Multidisciplinary
Jen-Hsu Chang, Chun-Yan Lin, Ray-Kuang Lee
Summary: By studying quantum particles with probability density-dependent effective mass in harmonic oscillators, we have revealed continuous energy spectra and stable solutions, showing the influence of nonlinear effective mass on the oscillator system and discovering new solutions.
Article
Mathematics
Laila F. Seddek, Abdelhalim Ebaid, Essam R. El-Zahar, Mona D. Aljoufi
Summary: This paper solves a generalized class of first-order fractional ordinary differential equations (1st-order FODEs) using the Riemann-Liouville fractional derivative (RLFD), intending to generalize some existing results in the literature. An effective method is used to solve non-homogeneous fractional differential systems with 2n periodic terms, determining exact solutions explicitly. The solutions are expressed in terms of entire functions with fractional order arguments. The features of the current solutions are discussed and analyzed, and the existing solutions in the literature are recovered as special cases of the obtained results.
Article
Physics, Multidisciplinary
Ville J. Harkonen, Ivan A. Gonoskov
Summary: A new method for diagonalizing quadratic Hamiltonians is introduced by changing the frame of reference through a unitary transformation. The paper presents a general approach for diagonalizing any quadratic Hamiltonian and provides detailed derivations for several simplest special cases.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Engineering, Electrical & Electronic
Sooyeon Kim, Daekeun Yoon, Jungsoo Kim, Junghwan Yoo, Kiryong Song, Jae-Sung Rieh
Summary: A triple-push sub-harmonic injection-locked ring tripler is introduced in this brief. The circuit converts a 100-GHz injection signal to an output signal of around 300 GHz. By employing a tri-layer dual coupled line composed of three layers of metal stack, the circuit can disturb the symmetry in the injection-locked ring tripler, leading to an enhancement in locking range.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2022)
Article
Chemistry, Physical
Yaming Zhang, Jiaheng Nie, Ruhao Liu, Baohua Teng, Lijie Li, Yan Zhang
Summary: Piezotronics is an emerging field involving high-performance piezoelectric semiconductor devices. This study proposes a theory of quantum piezotronics under nonuniform strain and demonstrates its impact on the performance of piezoelectric devices through experimental examples.
Article
Engineering, Mechanical
Jia Lou, Xiang Fang, Jianke Du, Huaping Wu
Summary: This study investigates the effects of nonlinear metasurfaces consisting of oscillator arrays on the propagation of Rayleigh waves. The results show that nonlinearities have a significant impact on dispersion and harmonic generation, and different types of nonlinearities can alter the frequency band characteristics of the metasurface.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Electrical & Electronic
Francesco Buccoleri, Andrea Bonfanti, Andrea L. Lacaita
Summary: This paper presents novel equations to describe the dependence of oscillation frequency on harmonic content in differential oscillators, rigorously considering the effect of common-mode oscillation. The inclusion of an additional term related to transistor current on drain voltage is disclosed for the first time, showing dominance in ohmic operation. Results obtained from applying this framework to Van der Pol oscillators in 28-nm bulk CMOS technology match well with detailed circuit simulations. The analysis reveals that the classical theory may not account for close-in phase noise performance when even harmonics are relevant, while the novel theoretical framework justifies the simulation results and explores new mechanisms of flicker noise up-conversion in the considered oscillator structures.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2021)
Article
Mathematics, Applied
R. Bobryk
Summary: Stochastic resonance in a harmonic oscillator with parametric bounded noise and external periodic force is investigated in this study. Multiple stochastic resonances are observed for spectral amplification, mean-square displacement, and variance, with relationships established with resonant tongues of the Mathieu equation. Similar effects can be observed in the case of harmonic noise external force, and the study also includes analysis of two coupled oscillators based on numerical matrix computations.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Automation & Control Systems
Jingyi Wang, Jianwen Feng, Yijun Lou, Guanrong Chen
Summary: This article proposes a quantized sampled velocity data coupling protocol for synchronization of harmonic oscillators, designed by interconnecting velocities encoded by a uniform quantizer with a zooming parameter. Sufficient conditions for convergence to synchronized orbits and effectiveness of the proposed coupling protocols are demonstrated through numerical examples.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2021)
Article
Engineering, Electrical & Electronic
Shunto Hirosawa, Koichi Narahara
Summary: A scheme for high-order subharmonic injection locking in a tunnel diode oscillator lattice loop is proposed in this study. The loop generates a rotary pulse through mutual synchronization between the component oscillators. A topological defect in the form of a dislocation is observed to rotate within the loop in the opposite direction of the background rotary pulse and is mutually synchronized with it. By injecting an external oscillator to lock the rotary behavior of the defect, the rotary pulse can also be locked. The operation principle is described and experimentally validated.
ELECTRONICS LETTERS
(2023)
Article
Chemistry, Physical
Shovan Manna, Suvonil Sinha Ray, Pradipta Ghosh, Sudip Chattopadhyay
Article
Chemistry, Physical
Sudip Chattopadhyay
Article
Chemistry, Physical
Suvonil Sinha Ray, Shovan Manna, Anirban Ghosh, Rajat K. Chaudhuri, Sudip Chattopadhyay
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2019)
Article
Chemistry, Physical
Sudip Chattopadhyay
JOURNAL OF PHYSICAL CHEMISTRY A
(2019)
Article
Chemistry, Physical
Sudip Chattopadhyay
JOURNAL OF PHYSICAL CHEMISTRY A
(2019)
Article
Chemistry, Physical
Shovan Manna, Suvonil Sinha Ray, Pradipta Ghosh, Sudip Chattopadhyay
Article
Chemistry, Physical
Shovan Manna, Suvonil Sinha Ray, Sudip Chattopadhyay, Rajat K. Chaudhuri
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Chemistry, Physical
Rajat K. Chaudhuri, Sudip Chattopadhyay
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Chemistry, Physical
Sudip Chattopadhyay
JOURNAL OF PHYSICAL CHEMISTRY A
(2020)
Article
Chemistry, Physical
Shovan Manna, Rajat K. Chaudhuri, Sudip Chattopadhyay
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Rajat K. Chaudhuri, Sudip Chattopadhyay
Summary: The electronic structural properties of methylene amidogene radical (H2CN) and its anion have been studied using CASCI and SSMRPT methods with DFT orbitals. The study confirms the electronic absorption band near 35,050 cm(-1) and suggests further experiments for assignment of a transition to the 35,600 cm(-1) band. The results are in close agreement with high-level theoretical estimates and contribute to a better understanding of vibrational assignments.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Multidisciplinary
Sudip Chattopadhyay
Summary: The state-specific Brillouin-Wigner multireference perturbation theory employing Jeziorski-Monkhorst parametrization with improved virtual orbitals, known as IVO-BWMRPT, is applied to calculate excitation energies for various systems with diradical character. The method provides results close to benchmark and experimental results, indicating balance in treatment of closed- and open-shell states. The good performance is attributed to the structural compactness of the formalism, showing promise for further development and applications in energy differences of strongly correlated systems.
Article
Chemistry, Physical
Rajat K. Chaudhuri, Sudip Chattopadhyay
Summary: The study proposes a mechanism for the sequential formation of poly-cyclic aromatic hydrocarbon (PAH) dication in the interstellar medium (ISM) and provides conclusions by measuring single-ionization and double-ionization energies, which are consistent with existing literature findings. It predicts the unlikely formation and fragmentation of dication in systems such as benzene and conjugated polyenes in the ISM H I regions.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Energy & Fuels
Rajib Adhikary, Abhishek De, Sudip Chattopadhyay, Jayati Datta
Summary: This study explores the contribution of transition metals, their oxides, and metal nanoparticles (NPs) towards oxygen reduction reaction (ORR) in alkaline medium for low-temperature direct ethanol fuel cells (DEFCs). The results show that the nanostructured Pd69Co31/MnO2 catalyst has a catalytic advantage over traditional Pd/C catalyst, reducing the overvoltage of ORR by approximately 85 mV and achieving a significant power density output of 45.5 mW/cm2.
Article
Nanoscience & Nanotechnology
Rajat K. Chaudhuri, Sudip Chattopadhyay
Summary: Exploration of tractable size basis sets for reliable estimation of computed properties in systems with heavy elements has been an area of interest in quantum chemistry. The segmented all-electron relativistically contracted (SARC) basis set proposed by Rolfes et al. appears promising for such studies. In this work, the properties of the Ag atom were computed using the SARC basis at the Fock-space multi-reference coupled cluster level of theory, and compared with results obtained using an even-tempered basis. The accuracy of the computed quantities demonstrates the effectiveness of the SARC basis for fully relativistic calculations, and the agreement with experimental and theoretical estimates further validates its use.
