Tootfinder

The NANOGrav 15 yr Data Set: Looking for Signs of Discreteness in the Gravitational-wave Background
Gabriella Agazie, Paul T. Baker, Bence B\'ecsy, Laura Blecha, Adam Brazier, Paul R. Brook, Lucas Brown, Sarah Burke-Spolaor, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Megan E. DeCesar, Paul B. Demorest, Heling Deng, Timothy Dolch, Elizabeth C. Ferrara, William Fiore, Emmanuel Fons…

The NANOGrav 15 yr Data Set: Looking for Signs of Discreteness in the Gravitational-wave Background
The cosmic merger history of supermassive black hole binaries (SMBHBs) is expected to produce a low-frequency gravitational wave background (GWB). Here we investigate how signs of the discrete nature of this GWB can manifest in pulsar timing arrays through excursions from, and breaks in, the expected $f_{\mathrm{GW}}^{-2/3}$ power-law of the GWB strain spectrum. To do this, we create a semi-analytic SMBHB population model, fit to NANOGrav's 15 yr GWB amplitude, and with 1,000 realizations we st…

Extending the Defect Tolerance of Halide Perovskite Nanocrystals to Hot Carrier Cooling Dynamics
Junzhi Ye, Navendu Mondal, Ben P. Carwithen, Yunwei Zhang, Linjie Dai, Xiangbin Fan, Jian Mao, Zhiqiang Cui, Pratyush Ghosh, Clara Otero Martinez, Lars van Turnhout, Zhongzheng Yu, Ziming Chen, Neil C. Greenham, Samuel D. Stranks, Lakshminarayana Polavarapu, Artem Bakulin, Akshay Rao, Robert L. Z. Hoye

Extending the Defect Tolerance of Halide Perovskite Nanocrystals to Hot Carrier Cooling Dynamics
Defect tolerance is a critical enabling factor for efficient lead-halide perovskite materials, but the current understanding is primarily on band-edge (cold) carriers, with significant debate over whether hot carriers (HCs) can also exhibit defect tolerance. Here, this important gap in the field is addressed by investigating how internationally-introduced traps affect HC relaxation in CsPbX3 nanocrystals (X = Br, I, or mixture). Using femtosecond interband and intraband spectroscopy, along with…

Finding Product and Sum Patterns in non-commutative settings
T. Y. Tao, Neil N. Y. Yang
https://arxiv.org/abs/2404.19650 https://arxi…

Finding Product and Sum Patterns in non-commutative settings
Hindman conjectured that any finite partition of $\mathbb{N}$ has a monochromatic $\{x,y,x+y,xy\}$. Recently, Bowen proved the result for all 2-partition. In this paper, we extend Bowen's result to any semiring $(S,+,\cdot)$ such that $Ss$ is piecewise syndetic for all $s\in S$. As a method, we gave a combinatorial proof for a piecewise syndetic version of Bergerson and Glasscock's IP$_r^*$ Szemerédi Theorem, and discussed the case when the operation is not commutative.

Twenty-nine million Intrinsic Q-factor Monolithic Microresonators on Thin Film Lithium Niobate
Xinrui Zhu, Yaowen Hu, Shengyuan Lu, Hana K. Warner, Xudong Li, Yunxiang Song, Leticia Magalhaes, Amirhassan Shams-Ansari, Neil Sinclair, Marko Loncar
https://arxiv.org/abs/2402.16161

Twenty-nine million Intrinsic Q-factor Monolithic Microresonators on Thin Film Lithium Niobate
The recent emergence of thin-film lithium niobate (TFLN) has extended the landscape of integrated photonics. This has been enabled by the commercialization of TFLN wafers and advanced nanofabrication of TFLN such as high-quality dry etching. However, fabrication imperfections still limit the propagation loss to a few dB/m, restricting the impact of this platform. Here, we demonstrate TFLN microresonators with a record-high intrinsic quality (Q) factor of twenty-nine million, corresponding to an…

Two-Dimensional Eclipse Mapping of the Hot Jupiter WASP-43b with JWST MIRI/LRS
Mark Hammond, Taylor J. Bell, Ryan C. Challener, Neil T. Lewis, Megan Weiner Mansfield, Isaac Malsky, Emily Rauscher, Jacob L. Bean, Ludmila Carone, Jo\~ao M. Mendon\c{c}a, Lucas Teinturier, Xianyu Tan, Nicolas Crouzet, Laura Kreidberg, Giuseppe Morello, Vivien Parmentier, Jasmina Blecic, Jean-Michel D\'esert, Christiane Helling, Pierre-Olivier Lagage, Karan Molaverdikhani, Matthew C. Nixon, Benjamin V. …

Two-Dimensional Eclipse Mapping of the Hot Jupiter WASP-43b with JWST MIRI/LRS
We present eclipse maps of the two-dimensional thermal emission from the dayside of the hot Jupiter WASP-43b, derived from an observation of a phase curve with the JWST MIRI/LRS instrument. The observed eclipse shapes deviate significantly from those expected for a planet emitting uniformly over its surface. We fit a map to this deviation, constructed from spherical harmonics up to order $\ell_{\rm max}=2$, alongside the planetary, orbital, stellar, and systematic parameters. This yields a map …

MAD Speech: Measures of Acoustic Diversity of Speech
Matthieu Futeral, Andrea Agostinelli, Marco Tagliasacchi, Neil Zeghidour, Eugene Kharitonov
https://arxiv.org/abs/2404.10419 <…

MAD Speech: Measures of Acoustic Diversity of Speech
Generative spoken language models produce speech in a wide range of voices, prosody, and recording conditions, seemingly approaching the diversity of natural speech. However, the extent to which generated speech is acoustically diverse remains unclear due to a lack of appropriate metrics. We address this gap by developing lightweight metrics of acoustic diversity, which we collectively refer to as MAD Speech. We focus on measuring five facets of acoustic diversity: voice, gender, emotion, accen…

Wavelength-accurate and wafer-scale process for nonlinear frequency mixers in thin-film lithium niobate
C. J. Xin, Shengyuan Lu, Jiayu Yang, Amirhassan Shams-Ansari, Boris Desiatov, Let\'icia S. Magalh\~aes, Soumya S. Ghosh, Erin McGee, Dylan Renaud, Nicholas Achuthan, Arseniy Zvyagintsev, David Barton III, Neil Sinclair, Marko Lon\v{c}ar
https:/…

Wavelength-accurate and wafer-scale process for nonlinear frequency mixers in thin-film lithium niobate
Recent advancements in thin-film lithium niobate (TFLN) photonics have led to a new generation of high-performance electro-optic devices, including modulators, frequency combs, and microwave-to-optical transducers. However, the broader adoption of TFLN-based devices that rely on all-optical nonlinearities have been limited by the sensitivity of quasi-phase matching (QPM), realized via ferroelectric poling, to fabrication tolerances. Here, we propose a scalable fabrication process aimed at impro…