Tootfinder

This https://arxiv.org/abs/2308.15836 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Position dependence of Nielsen complexity for the Thermofield double state
In this paper, the Nielsen geometric method is used to study the position dependence of the Nielsen complexity for the thermofield double state of a harmonic oscillator. We present the state shift under the influence of an external electric field and demonstrate its importance for the construction of the corresponding circuit. By numerical analysis, we investigate the effect of the frequency and the external field on the dynamics of complexity. Our observation reveals that the system's complexi…

This https://arxiv.org/abs/2307.13450 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Complexity for one-dimensional discrete time quantum walk circuits
We compute the complexity for the mixed state density operator derived from a one-dimensional discrete-time quantum walk (DTQW). The complexity is computed using a two-qubit quantum circuit obtained from canonically purifying the mixed state. We demonstrate that the Nielson complexity for the unitary evolution oscillates around a mean circuit depth of $k$. Further, the complexity of the step-wise evolution operator grows cumulatively and linearly with the steps. From a quantum circuit perspecti…

Scalar field dark matter with time-varying equation of state
Gaspard Poulot, Elsa M. Teixeira, Carsten van de Bruck, Nelson J. Nunes
https://arxiv.org/abs/2404.10524

Scalar field dark matter with time-varying equation of state
We propose a new model of scalar field dark matter interacting with dark energy. Adopting a fluid description of the dark matter field in the regime of rapid oscillations, we find that the equation of state for dark matter is non-zero and even becomes increasingly negative at late times during dark energy domination. Furthermore, the speed of sound of dark matter is non-vanishing at all length scales, and a non-adiabatic pressure contribution arises. The results indicate that there are still un…

Kerr optical frequency division with integrated photonics for stable microwave and mmWave generation
Shuman Sun, Mark W. Harrington, Fatemehsadat Tabatabaei, Samin Hanifi, Kaikai Liu, Jiawei Wang, Beichen Wang, Zijiao Yang, Ruxuan Liu, Jesse S. Morgan, Steven M. Bowers, Paul A. Morton, Karl D. Nelson, Andreas Beling, Daniel J. Blumenthal, Xu Yi
https…

Kerr optical frequency division with integrated photonics for stable microwave and mmWave generation
Optical frequency division (OFD) has revolutionized microwave and mmWave generation and set spectral purity records owing to its unique capability to transfer high fractional stability from optical to electronic frequencies. Recently, rapid developments in integrated optical reference cavities and microresonator-based optical frequency combs (microcombs) have created a path to transform OFD technology to chip scale. Here, we demonstrate an ultra-low phase noise mmWave oscillator by leveraging i…

This https://arxiv.org/abs/2307.13736 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Geometric quantum complexity of bosonic oscillator systems
According to the pioneering work of Nielsen and collaborators, the length of the minimal geodesic in a geometric realization of a suitable operator space provides a measure of the quantum complexity of an operation. Compared with the original concept of complexity based on the minimal number of gates required to construct the desired operation as a product, this geometrical approach amounts to a more concrete and computable definition, but its evaluation is nontrivial in systems with a high-dim…

A toy model for gas sloshing in galaxy clusters
Elke Roediger, Iraj Vaezzadeh, Paul Nulsen
https://arxiv.org/abs/2402.18632 https://a…

A toy model for gas sloshing in galaxy clusters
We apply a toy model based on 'pendulum waves' to gas sloshing in galaxy clusters. Starting with a galaxy cluster potential filled with a hydrostatic intra-cluster medium (ICM), we perturb all ICM by an initial small, unidirectional velocity, i.e., an instantaneous kick. Consequently, each parcel of ICM will oscillate due to buoyancy with its local Brunt-Väisälä (BV) period, which we show to be approximately proportional to the cluster radius. The oscillation of gas parcels at different radi…

Scalar field dark matter with time-varying equation of state
Gaspard Poulot, Elsa M. Teixeira, Carsten van de Bruck, Nelson J. Nunes
https://arxiv.org/abs/2404.10524

Scalar field dark matter with time-varying equation of state
We propose a new model of scalar field dark matter interacting with dark energy. Adopting a fluid description of the dark matter field in the regime of rapid oscillations, we find that the equation of state for dark matter is non-zero and even becomes increasingly negative at late times during dark energy domination. Furthermore, the speed of sound of dark matter is non-vanishing at all length scales, and a non-adiabatic pressure contribution arises. The results indicate that there are still un…