المؤلفون: Aamlid, Solveig Stubmo, Kim, Minu, González-Rivas, Mario U., Oudah, Mohamed, Takagi, Hidenori, Hallas, Alannah M.

المصدر: Appl. Phys. Lett. 125, 021901 (2024)

مصطلحات موضوعية: Condensed Matter - Materials Science, Condensed Matter - Disordered Systems and Neural Networks

الوصف: High entropy materials are often entropy stabilized, meaning that the configurational entropy from multiple elements sharing a single lattice site stabilizes the structure. In this work, we study how high-pressure synthesis conditions can stabilize or destabilize a high entropy oxide (HEO). We study the high-pressure and high-temperature phase equilibria of two well-known families of HEOs: the rock-salt structured compound (Mg,Co,Ni,Cu,Zn)O including some cation substitutions and the spinel structured (Cr,Mn,Fe,Co,Ni)$_3$O$_4$. Syntheses were performed at various temperatures, pressures, and oxygen activity levels resulting in dramatically different synthesis outcomes. In particular, in the rock salt HEO we observe the competing tenorite and wurtzite phases and the possible formation of a layered rock salt phase, while the spinel HEO is highly susceptible to decomposition into a mixture of rock-salt and corundum phases. At the highest tested pressures, 15 GPa, we discover the transformation of the spinel HEO into a metastable modified ludwigite-type structure with nominal formula (Cr,Mn,Fe,Co,Ni)$_4$O$_5$. The relationship between the synthesis conditions and the final reaction product is not straightforward. Nonetheless, we conclude that high-pressure conditions provide an important opportunity to synthesize high entropy phases that cannot be formed any other way.
Comment: This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing

الوصول الحر: http://arxiv.org/abs/2407.06388Test

المؤلفون: LLM-jp, Aizawa, Akiko, Aramaki, Eiji, Chen, Bowen, Cheng, Fei, Deguchi, Hiroyuki, Enomoto, Rintaro, Fujii, Kazuki, Fukumoto, Kensuke, Fukushima, Takuya, Han, Namgi, Harada, Yuto, Hashimoto, Chikara, Hiraoka, Tatsuya, Hisada, Shohei, Hosokawa, Sosuke, Jie, Lu, Kamata, Keisuke, Kanazawa, Teruhito, Kanezashi, Hiroki, Kataoka, Hiroshi, Katsumata, Satoru, Kawahara, Daisuke, Kawano, Seiya, Keyaki, Atsushi, Kiryu, Keisuke, Kiyomaru, Hirokazu, Kodama, Takashi, Kubo, Takahiro, Kuga, Yohei, Kumon, Ryoma, Kurita, Shuhei, Kurohashi, Sadao, Li, Conglong, Maekawa, Taiki, Matsuda, Hiroshi, Miyao, Yusuke, Mizuki, Kentaro, Mizuki, Sakae, Murawaki, Yugo, Nakamura, Ryo, Nakamura, Taishi, Nakayama, Kouta, Nakazato, Tomoka, Niitsuma, Takuro, Nishitoba, Jiro, Oda, Yusuke, Ogawa, Hayato, Okamoto, Takumi, Okazaki, Naoaki, Oseki, Yohei, Ozaki, Shintaro, Ryu, Koki, Rzepka, Rafal, Sakaguchi, Keisuke, Sasaki, Shota, Sekine, Satoshi, Suda, Kohei, Sugawara, Saku, Sugiura, Issa, Sugiyama, Hiroaki, Suzuki, Hisami, Suzuki, Jun, Suzumura, Toyotaro, Tachibana, Kensuke, Takagi, Yu, Takami, Kyosuke, Takeda, Koichi, Takeshita, Masashi, Tanaka, Masahiro, Taura, Kenjiro, Tolmachev, Arseny, Ueda, Nobuhiro, Wan, Zhen, Yada, Shuntaro, Yahata, Sakiko, Yamamoto, Yuya, Yamauchi, Yusuke, Yanaka, Hitomi, Yokota, Rio, Yoshino, Koichiro

مصطلحات موضوعية: Computer Science - Computation and Language, Computer Science - Artificial Intelligence

الوصف: This paper introduces LLM-jp, a cross-organizational project for the research and development of Japanese large language models (LLMs). LLM-jp aims to develop open-source and strong Japanese LLMs, and as of this writing, more than 1,500 participants from academia and industry are working together for this purpose. This paper presents the background of the establishment of LLM-jp, summaries of its activities, and technical reports on the LLMs developed by LLM-jp. For the latest activities, visit https://llm-jp.nii.ac.jp/enTest/.

الوصول الحر: http://arxiv.org/abs/2407.03963Test

المؤلفون: Watanabe, Kaito, Takagi, Ryuji

مصطلحات موضوعية: Quantum Physics, Condensed Matter - Statistical Mechanics

الوصف: Work extraction is one of the most central processes in quantum thermodynamics. However, the prior analysis of optimal extractable work has been restricted to a limited operational scenario where complete information about the initial state is given. Here, we introduce a general framework of black box work extraction, which addresses the inaccessibility of information on the initial state. We show that the optimal extractable work in the black box setting is completely characterized by the performance of a composite hypothesis testing task, a fundamental problem in information theory.We employ this general relation to reduce the asymptotic black box work extraction to the quantum Stein's lemma in composite hypothesis testing, allowing us to provide their exact characterization in terms of the Helmholtz free energy. We also show a new quantum Stein's lemma motivated in this physical setting, where a composite hypothesis contains a certain correlation. Our work exhibits the importance of information about the initial state and gives a new interpretation of the quantities in the composite quantum hypothesis testing, encouraging the interplay between the physical settings and the information theory.
Comment: 5+21 pages, 2 figures

الوصول الحر: http://arxiv.org/abs/2407.03400Test

المؤلفون: Telescope Array Collaboration, Abbasi, R. U., Abe, Y., Abu-Zayyad, T., Allen, M., Arai, Y., Arimura, R., Barcikowski, E., Belz, J. W., Bergman, D. R., Blake, S. A., Buckland, I., Cheon, B. G., Chikawa, M., Fujii, T., Fujisue, K., Fujita, K., Fujiwara, R., Fukushima, M., Furlich, G., Globus, N., Gonzalez, R., Hanlon, W., Hayashida, N., He, H., Hibi, R., Hibino, K., Higuchi, R., Honda, K., Ikeda, D., Inoue, N., Ishii, T., Ito, H., Ivanov, D., Iwasaki, A., Jeong, H. M., Jeong, S., Jui, C. C. H., Kadota, K., Kakimoto, F., Kalashev, O., Kasahara, K., Kasami, S., Kawakami, S., Kawata, K., Kharuk, I., Kido, E., Kim, H. B., Kim, J. H., Kim, S. W., Kimura, Y., Komae, I., Kuzmin, V., Kuznetsov, M., Kwon, Y. J., Lee, K. H., Lubsandorzhiev, B., Lundquist, J. P., Matsumiya, H., Matsuyama, T., Matthews, J. N., Mayta, R., Mizuno, K., Murakami, M., Myers, I., Nagataki, S., Nakai, K., Nakamura, T., Nishio, E., Nonaka, T., Oda, H., Ogio, S., Onishi, M., Ohoka, H., Okazaki, N., Oku, Y., Okuda, T., Omura, Y., Ono, M., Oshima, A., Oshima, H., Ozawa, S., Park, I. H., Park, K. Y., Potts, M., Pshirkov, M. S., Remington, J., Rodriguez, D. C., Rott, C., Rubtsov, G. I., Ryu, D., Sagawa, H., Saito, R., Sakaki, N., Sako, T., Sakurai, N., Sato, D., Sato, K., Sato, S., Sekino, K., Shah, P. D., Shibata, N., Shibata, T., Shikita, J., Shimodaira, H., Shin, B. K., Shin, H. S., Shinto, D., Smith, J. D., Sokolsky, P., Stokes, B. T., Stroman, T. A., Takagi, Y., Takahashi, K., Takamura, M., Takeda, M., Takeishi, R., Taketa, A., Takita, M., Tameda, Y., Tanaka, K., Tanaka, M., Tanoue, Y., Thomas, S. B., Thomson, G. B., Tinyakov, P., Tkachev, I., Tokuno, H., Tomida, T., Troitsky, S., Tsuda, R., Tsunesada, Y., Udo, S., Urban, F., Warren, D., Wong, T., Yamazaki, K., Yashiro, K., Yoshida, F., Zhezher, Y., Zundel, Z.

مصطلحات موضوعية: Astrophysics - High Energy Astrophysical Phenomena

الوصف: We report an estimation of the injected mass composition of ultra-high energy cosmic rays (UHECRs) at energies higher than 10 EeV. The composition is inferred from an energy-dependent sky distribution of UHECR events observed by the Telescope Array surface detector by comparing it to the Large Scale Structure of the local Universe. In the case of negligible extra-galactic magnetic fields the results are consistent with a relatively heavy injected composition at E ~ 10 EeV that becomes lighter up to E ~ 100 EeV, while the composition at E > 100 EeV is very heavy. The latter is true even in the presence of highest experimentally allowed extra-galactic magnetic fields, while the composition at lower energies can be light if a strong EGMF is present. The effect of the uncertainty in the galactic magnetic field on these results is subdominant.
Comment: 8 pages, 3 figures, accepted for publication in PRL

الوصول الحر: http://arxiv.org/abs/2406.19287Test

المؤلفون: Telescope Array Collaboration, Abbasi, R. U., Abe, Y., Abu-Zayyad, T., Allen, M., Arai, Y., Arimura, R., Barcikowski, E., Belz, J. W., Bergman, D. R., Blake, S. A., Buckland, I., Cheon, B. G., Chikawa, M., Fujii, T., Fujisue, K., Fujita, K., Fujiwara, R., Fukushima, M., Furlich, G., Globus, N., Gonzalez, R., Hanlon, W., Hayashida, N., He, H., Hibi, R., Hibino, K., Higuchi, R., Honda, K., Ikeda, D., Inoue, N., Ishii, T., Ito, H., Ivanov, D., Iwasaki, A., Jeong, H. M., Jeong, S., Jui, C. C. H., Kadota, K., Kakimoto, F., Kalashev, O., Kasahara, K., Kasami, S., Kawakami, S., Kawata, K., Kharuk, I., Kido, E., Kim, H. B., Kim, J. H., Kim, S. W., Kimura, Y., Komae, I., Kuzmin, V., Kuznetsov, M., Kwon, Y. J., Lee, K. H., Lubsandorzhiev, B., Lundquist, J. P., Matsumiya, H., Matsuyama, T., Matthews, J. N., Mayta, R., Mizuno, K., Murakami, M., Myers, I., Nagataki, S., Nakai, K., Nakamura, T., Nishio, E., Nonaka, T., Oda, H., Ogio, S., Onishi, M., Ohoka, H., Okazaki, N., Oku, Y., Okuda, T., Omura, Y., Ono, M., Oshima, A., Oshima, H., Ozawa, S., Park, I. H., Park, K. Y., Potts, M., Pshirkov, M. S., Remington, J., Rodriguez, D. C., Rott, C., Rubtsov, G. I., Ryu, D., Sagawa, H., Saito, R., Sakaki, N., Sako, T., Sakurai, N., Sato, D., Sato, K., Sato, S., Sekino, K., Shah, P. D., Shibata, N., Shibata, T., Shikita, J., Shimodaira, H., Shin, B. K., Shin, H. S., Shinto, D., Smith, J. D., Sokolsky, P., Stokes, B. T., Stroman, T. A., Takagi, Y., Takahashi, K., Takamura, M., Takeda, M., Takeishi, R., Taketa, A., Takita, M., Tameda, Y., Tanaka, K., Tanaka, M., Tanoue, Y., Thomas, S. B., Thomson, G. B., Tinyakov, P., Tkachev, I., Tokuno, H., Tomida, T., Troitsky, S., Tsuda, R., Tsunesada, Y., Udo, S., Urban, F., Warren, D., Wong, T., Yamazaki, K., Yashiro, K., Yoshida, F., Zhezher, Y., Zundel, Z.

مصطلحات موضوعية: Astrophysics - High Energy Astrophysical Phenomena

الوصف: We use a new method to estimate the injected mass composition of ultrahigh cosmic rays (UHECRs) at energies higher than 10 EeV. The method is based on comparison of the energy-dependent distribution of cosmic ray arrival directions as measured by the Telescope Array experiment (TA) with that calculated in a given putative model of UHECR under the assumption that sources trace the large-scale structure (LSS) of the Universe. As we report in the companion letter, the TA data show large deflections with respect to the LSS which can be explained, assuming small extra-galactic magnetic fields (EGMF), by an intermediate composition changing to a heavy one (iron) in the highest energy bin. Here we show that these results are robust to uncertainties in UHECR injection spectra, the energy scale of the experiment and galactic magnetic fields (GMF). The assumption of weak EGMF, however, strongly affects this interpretation at all but the highest energies E > 100 EeV, where the remarkable isotropy of the data implies a heavy injected composition even in the case of strong EGMF. This result also holds if UHECR sources are as rare as $2 \times 10^{-5}$ Mpc$^{-3}$, that is the conservative lower limit for the source number density.
Comment: 18 pages, 11 figures, accepted for publication in PRD

الوصول الحر: http://arxiv.org/abs/2406.19286Test

المؤلفون: Takagi, Hiromichi

مصطلحات موضوعية: Mathematics - Algebraic Geometry

الوصف: In the previous papers [Tak8,Tak6], we construct the affine varieties $\Sigma_{\mathbb{A}}^{13}$ and $\Pi_{\mathbb{A}}^{14}$ whose partial projectivizations have $\mathbb{P}^{2}\times\mathbb{P}^{2}$-fibrations. In this paper, we produce prime $\mathbb{Q}$-Fano 3-folds of anticanonical codimension 4 belonging to 23 (resp. 8) classes of Graded Ring Database [GRDB] as weighted complete intersections of weighted projectivizations of $\Sigma_{\mathbb{A}}^{13}$ (resp. $\Pi_{\mathbb{A}}^{14}$ or the cone over it). Together with the results of [CD] and [Tak5], prime $\mathbb{Q}$-Fano 3-folds of anticanonical codimension 4 are constructed for 141 classes among the 143 classes in [GRDB].
Comment: The contents of this paper consist of those of the part of [Tak2] and [Tak3] where we construct examples of $\mathbb{Q}$-Fano threefolds. arXiv admin note: substantial text overlap with arXiv:2103.11086, arXiv:2111.14328

الوصول الحر: http://arxiv.org/abs/2407.06200Test

المؤلفون: Petry, Dirk, Trigo, María Díaz, Kneissl, Rüdiger, Toledo, Ignacio, Miyazaki, Atsushi, Takagi, Toshinobu, Barnes, Ashley, Bonanomi, Francesca

مصطلحات موضوعية: Astrophysics - Instrumentation and Methods for Astrophysics

الوصف: The Atacama Large Millimeter/submillimeter Array remains the largest mm radio interferometer observatory world-wide. It is now conducting its 11th observing cycle. In our previous paper presented at this conference series in 2020, we outlined a number of possible improvements to the ALMA end-to-end observing and data processing procedures which could further optimize the uv coverage and thus the image quality while at the same time improving the observing efficiency. Here we report an update of our results refining our proposed adjustments to the scheduling and quality assurance processes. In particular we present new results on ways to assess the uv coverage of a given observation efficiently, methods to define and measure the maximum recoverable angular scale, and on the robustness of the deconvolution in the final interferometric imaging process w.r.t. defects in the uv coverage. Finally we present the outline of a design for integrating uv coverage assessment into the control and processing loop of observation scheduling. The results are applicable to all radio interferometers with more than approx. 10 antennas.
Comment: 12 pages, 8 figures, to be published in the proceedings of SPIE Astronomical Telescopes and Instrumentation, 2024, Yokohama, paper no. 13098-27

الوصول الحر: http://arxiv.org/abs/2406.13199Test

المؤلفون: The Telescope Array Collaboration, Abbasi, R. U., Abu-Zayyad, T., Allen, M., Belz, J. W., Bergman, D. R., Buckland, I., Campbell, W., Cheon, B. G., Endo, K., Fedynitch, A., Fujii, T., Fujisue, K., Fujita, K., Fukushima, M., Furlich, G., Gerber, Z., Globus, N., Hanlon, W., Hayashida, N., He, H., Hibino, K., Higuchi, R., Ikeda, D., Ishii, T., Ivanov, D., Jeong, S., Jui, C. C. H., Kadota, K., Kakimoto, F., Kalashev, O., Kasahara, K., Kawachi, Y., Kawata, K., Kharuk, I., Kido, E., Kim, H. B., Kim, J. H., Kim, S. W., Kobo, R., Komae, I., Komatsu, K., Komori, K., Koyama, C., Kudenko, M., Kuroiwa, M., Kusumori, Y., Kuznetsov, M., Kwon, Y. J., Lee, K. H., Lee, M. J., Lubsandorzhiev, B., Lundquist, J. P., Matsuzawa, A., Matthews, J. A., Matthews, J. N., Mizuno, K., Mori, M., Murakami, M., Nagataki, S., Nakahara, M., Nakamura, T., Nakayama, T., Nakayama, Y., Nonaka, T., Ogio, S., Ohoka, H., Okazaki, N., Onishi, M., Oshima, A., Oshima, H., Ozawa, S., Park, I. H., Park, K. Y., Potts, M., Przybylak, M., Pshirkov, M. S., Remington, J., Rott, C., Rubtsov, G. I., Ryu, D., Sagawa, H., Sakaki, N., Sakamoto, R., Sako, T., Sakurai, N., Sakurai, S., Sato, D., Sato, S., Sekino, K., Shibata, T., Shikita, J., Shimodaira, H., Shin, B. K., Shin, H. S., Shinozaki, K., Smith, J. D., Sokolsky, P., Stokes, B. T., Stroman, T. A., Takagi, Y., Takahashi, K., Takeda, M., Takeishi, R., Taketa, A., Takita, M., Tameda, Y., Tanaka, K., Tanaka, M., Thomas, S. B., Thomson, G. B., Tinyakov, P., Tkachev, I., Tomida, T., Troitsky, S., Tsunesada, Y., Udo, S., Urban, F., Vaiman, I. A., Vrábel, M., Warren, D., Yamazaki, K., Zhezher, Y., Zundel, Z., Zvirzdin, J.

مصطلحات موضوعية: Astrophysics - High Energy Astrophysical Phenomena

الوصف: We report on an observation of the difference between northern and southern skies of the ultrahigh energy cosmic ray energy spectrum with a significance of ${\sim}8\sigma$. We use measurements from the two largest experiments$\unicode{x2014}$the Telescope Array observing the northern hemisphere and the Pierre Auger Observatory viewing the southern hemisphere. Since the comparison of two measurements from different observatories introduces the issue of possible systematic differences between detectors and analyses, we validate the methodology of the comparison by examining the region of the sky where the apertures of the two observatories overlap. Although the spectra differ in this region, we find that there is only a $1.8\sigma$ difference between the spectrum measurements when anisotropic regions are removed and a fiducial cut in the aperture is applied.
Comment: 8 pages, 6 figures

الوصول الحر: http://arxiv.org/abs/2406.08612Test

المؤلفون: Hahn, Oliver, Ferrini, Giulia, Takagi, Ryuji

مصطلحات موضوعية: Quantum Physics

الوصف: Although the similarity between non-stabilizer states -- also known as magic states -- in discrete-variable systems and non-Gaussian states in continuous-variable systems has widely been recognized, the precise connections between these two notions have still been unclear. We establish a fundamental link between these two quantum resources via the Gottesman-Kitaev-Preskill (GKP) encoding. We show that the negativity of the continuous-variable Wigner function for an encoded GKP state coincides with a magic measure we introduce, which matches the negativity of the discrete Wigner function for odd dimensions. We also provide a continuous-variable representation of the stabilizer R\'enyi entropy -- a recent proposal for a magic measure for multi-qubit states. With this in hand, we give a classical simulation algorithm with runtime scaling with the resource contents, quantified by our magic measures. We also employ our results to prove that implementing a multi-qubit logical non-Clifford operation in the GKP code subspace requires a non-Gaussian operation even at the limit of perfect encoding, despite the fact that the ideal GKP states already come with a large amount of non-Gaussianity.

الوصول الحر: http://arxiv.org/abs/2406.06418Test

المؤلفون: Kanamori, Kentaro, Takagi, Takuya, Kobayashi, Ken, Ike, Yuichi

مصطلحات موضوعية: Computer Science - Machine Learning, Statistics - Machine Learning

الوصف: This paper proposes a new algorithm for learning accurate tree-based models while ensuring the existence of recourse actions. Algorithmic Recourse (AR) aims to provide a recourse action for altering the undesired prediction result given by a model. Typical AR methods provide a reasonable action by solving an optimization task of minimizing the required effort among executable actions. In practice, however, such actions do not always exist for models optimized only for predictive performance. To alleviate this issue, we formulate the task of learning an accurate classification tree under the constraint of ensuring the existence of reasonable actions for as many instances as possible. Then, we propose an efficient top-down greedy algorithm by leveraging the adversarial training techniques. We also show that our proposed algorithm can be applied to the random forest, which is known as a popular framework for learning tree ensembles. Experimental results demonstrated that our method successfully provided reasonable actions to more instances than the baselines without significantly degrading accuracy and computational efficiency.
Comment: 27 pages, 10 figures, to appear in the 41st International Conference on Machine Learning (ICML 2024)

الوصول الحر: http://arxiv.org/abs/2406.01098Test