Tootfinder

Learning mixed quantum states in large-scale experiments
Matteo Votto, Marko Ljubotina, C\'ecilia Lancien, J. Ignacio Cirac, Peter Zoller, Maksym Serbyn, Lorenzo Piroli, Beno\^it Vermersch
https://arxiv.org/abs/2507.12550

Learning mixed quantum states in large-scale experiments
We present and test a protocol to learn the matrix-product operator (MPO) representation of an experimentally prepared quantum state. The protocol takes as an input classical shadows corresponding to local randomized measurements, and outputs the tensors of a MPO which maximizes a suitably-defined fidelity with the experimental state. The tensor optimization is carried out sequentially, similarly to the well-known density matrix renormalization group algorithm. Our approach is provably efficien…

Gravitational Waves from Spectator Scalar Fields
Marcos A. G. Garcia, Sarunas Verner
https://arxiv.org/abs/2506.12126 https://arxiv.o…

Gravitational Waves from Spectator Scalar Fields
We propose a novel mechanism for gravitational wave (GW) production sourced by spectator scalar fields during inflation. These fields, while not driving cosmic expansion, generate blue-tilted isocurvature fluctuations that naturally satisfy current CMB constraints at large scales while producing enhanced power spectra at smaller scales accessible to GW detectors. The resulting GW spectrum spans an exceptionally broad frequency range from $10^{-20}$ to $1$ Hz, with amplitudes ranging from $Ω_{\…

Switchbacks near Boundaries of Small-scale Magnetic Flux Ropes in the Young Solar Wind from Parker Solar Probe Observations
Kyung-Eun Choi, Oleksiy V. Agapitov, Dae-Young Lee, Forrest Mozer, Jia Huang, Lucas Colomban, Jaye L. Verniero, Nour Raouafi
https://arxiv.org/abs/2506.08278

Switchbacks near Boundaries of Small-scale Magnetic Flux Ropes in the Young Solar Wind from Parker Solar Probe Observations
The Parker Solar Probe (PSP) mission has revealed frequent occurrences of switchbacks (SBs) and small-scale magnetic flux ropes (SMFRs) as prominent structures within the solar wind. These mesoscale features are observed across all heliocentric distances, with heightened activity in the young solar wind, such as successive SMFRs, blobs, and SBs using PSP in situ observations. One study, in particular, focuses on SMFRs observed during the intervals of PSP co-rotating with the Sun, which suggests…

Failing Banks
Sergio Correia, Stephan Luck, Emil Verner
https://arxiv.org/abs/2506.06082 https://arxiv.org/pdf/2506.06082

Failing Banks
Why do banks fail? We create a panel covering most commercial banks from 1863 through 2024 to study the history of failing banks in the United States. Failing banks are characterized by rising asset losses, deteriorating solvency, and an increasing reliance on expensive noncore funding. These commonalities imply that bank failures are highly predictable using simple accounting metrics from publicly available financial statements. Failures with runs were common before deposit insurance, but thes…

Collecting, Curating, and Annotating Good Quality Speech deepfake dataset for Famous Figures: Process and Challenges
Hashim Ali, Surya Subramani, Raksha Varahamurthy, Nithin Adupa, Lekha Bollinani, Hafiz Malik
https://arxiv.org/abs/2507.00324

Collecting, Curating, and Annotating Good Quality Speech deepfake dataset for Famous Figures: Process and Challenges
Recent advances in speech synthesis have introduced unprecedented challenges in maintaining voice authenticity, particularly concerning public figures who are frequent targets of impersonation attacks. This paper presents a comprehensive methodology for collecting, curating, and generating synthetic speech data for political figures and a detailed analysis of challenges encountered. We introduce a systematic approach incorporating an automated pipeline for collecting high-quality bonafide speec…