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23rd International Conference on computers in Education, ICCE 2015

作者： Hiangsa, Marisa Srisawasdi, Niwat Feungchan, Witcha Science Education Program Faculty of Education Khon Kaen University Thailand Division of Science Mathematics and Technology Faculty of Education Khon Kaen University Thailand Department of Computer Engineering Faculty of Engineering Khon Kaen University Thailand

ISBN: (纸本)9784990801472

Recently, effective instructional interventions are needed to enable primary school student to increase conceptual understanding in science. To archive the mentioned, well-designed instructional materials regarding appropriate pedagogy is an important platform for students' learning in primary school science. In this study, an educational digital game regarding fruit and vegetable consumptions, particularly called "The Fruit Eater", has been pedagogically designed concerning problem-based learning strategy and then collaboratively created in android application platform, under the cooperation by computer engineering, science educator, and in-service science teacher at Khon Kaen University, in order to transforming traditional learning environment into constructivist-based learning environment. To investigate the effect of the intervention, a study has been conducted with 104 primary school students, classifying into three different groups, in order to verify the value of the game app. The results showed that the game demonstrated good performance (as compared to regular traditional (problem-based) instruction, and problem-oriented game-based inquiry learning) concerning the gain of conceptual understanding of vitamins, and health benefits of fruits and vegetables, even though the pedagogy-embedded digital game was used independently by students for learning. To this end, this study concluded that the use of pedagogy-embedded digital game could facilitate students' development of scientific understanding as well as teacher-centered instruction, and well-designed digital game regarding appropriate pedagogy might be a key factor associated to this effect in science learning.

关键词： Students

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EEG channels reduction using PCA to increase XGBoost’s accuracy for stroke detection

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AIP Conference Proceedings 2017年第1期1862卷

作者： N. Fitriah S. K. Wijaya M. I. Fanany C. Badri M. Rezal 1Biomedical Engineering Study Program Universitas Indonesia Jl. Salemba Raya No. 4 Jakarta 10430 DKI Jakarta Indonesia 2Department of Physics Faculty of Mathematics and Natural Sciences (FMIPA) Universitas Indonesia Depok 16424 Indonesia 3Faculty of Computer Science Universitas Indonesia Depok 16424 Indonesia

In Indonesia, based on the result of Basic Health Research 2013, the number of stroke patients had increased from 8.3 ‰ (2007) to 12.1 ‰ (2013). These days, some researchers are using electroencephalography (EEG) result as another option to detect the stroke disease besides CT Scan image as the gold standard. A previous study on the data of stroke and healthy patients in National Brain Center Hospital (RS PON) used Brain Symmetry Index (BSI), Delta-Alpha Ratio (DAR), and Delta-Theta-Alpha-Beta Ratio (DTABR) as the features for classification by an Extreme Learning Machine (ELM). The study got 85% accuracy with sensitivity above 86 % for acute ischemic stroke detection. Using EEG data means dealing with many data dimensions, and it can reduce the accuracy of classifier (the curse of dimensionality). Principal Component Analysis (PCA) could reduce dimensionality and computation cost without decreasing classification accuracy. XGBoost, as the scalable tree boosting classifier, can solve real-world scale problems (Higgs Boson and Allstate dataset) with using a minimal amount of resources. This paper reuses the same data from RS PON and features from previous research, preprocessed with PCA and classified with XGBoost, to increase the accuracy with fewer electrodes. The specific fewer electrodes improved the accuracy of stroke detection. Our future work will examine the other algorithm besides PCA to get higher accuracy with less number of channels.

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Engaging end-users in creating data-intensive mobile applications: A creative 'e-learning-by-doing' approach

Engaging end-users in creating data-intensive mobile applica...

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International Conference on Interactive Mobile Communication Technologies and Learning, IMCL 2015

作者： Tzafilkou, Katerina Chouliara, Adamantia Protogeros, Nicolaos Karagiannidis, Charalampos Koumpis, Adamantios Postgraduate Studies Program in Information Systems University of Macedonia Thessaloniki Greece Department of Special Education University of Thessaly Volos Greece Faculty of Computer Science and Mathematics University of Passau Passau Germany

ISBN: (纸本)9781467382434

Engaging end-users in creative and experiential e-learning activities by giving them the 'right tools' can be viewed as a way to empower end-users in developing their own artifacts. The aim of this paper is to propose 'e-learning-by-developing', a creative learning-by-experience methodology, that can support end-users to develop data intensive mobile applications. The proposed learning approach aims to create a training model for the acquisition of knowledge and development of skills for database-driven applications, by promoting active participation of the-user in the development process. Preliminary experimental evaluation showed that end-users, with limited prior database knowledge and development background, were able to quickly and efficiently design a relational scheme and create a reusable database driven mobile application. © 2015 IEEE.

关键词： Database systems

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An application program of fingerprint detection using wavelet transform for authentication

An application program of fingerprint detection using wavele...

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Management and Innovation Technology International Conference (MITicon)

作者： Aunchisa Kwaochai Surapong Pongyupinpanich Pratya Areekul Wimol San-Um Thai-Nichi Institute of Technology Bangkok TH Realtime Information Electronics and Embedded Systems (RIEES) Master Program of Forensic Informatics Ramkhamhang University Huamark Bangkapi Bangkok Thailand 10240 Department of Mathematics and Computer Science Chulachomklao Royal Military Academy (CRMA) Amphor Mueng Tambol Promanee Province Nakornnayok Thailand

ISBN: (纸本)9781509041060

This paper presents the application program of fingerprint detection using wavelet transform for authentication. Fingerprints are obtained from the site of crime, old documents and excavated things. This paper proposes a fingerprint recognition technique based on wavelet-based texture pattern recognition method. By collecting incomplete fingerprints of 2 people with 6 images each. The original seven of uncompleted fingerprint images were undetected and only one was detected. After enhancing image quality using wavelet transform method, it was found that those of seven images were completed. The comparison method was a matching technique. This work focuses on the ability of the program and knowledge of image processing by studying algorithms of image processing. In design algorithm process, different technique enhancements were employed as well as the study of different of filters and algorithms based on existing research results from literature.

关键词： Fingerprint recognition Image matching Discrete wavelet transforms Time-frequency analysis Continuous wavelet transforms

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A demonstration of improved constraints on primordial gravitational waves with delensing

arXiv

引用

arXiv 2020年

作者： Ade, P.A.R. Ahmed, Z. Amiri, M. Anderson, A.J. Austermann, J.E. Avva, J.S. Barkats, D. Thakur, R. Basu Beall, J.A. Bender, A.N. Benson, B.A. Bianchini, F. Bischoff, C.A. Bleem, L.E. Bock, J.J. Boenish, H. Bullock, E. Buza, V. Carlstrom, J.E. Chang, C.L. Cheshire, J.R. Chiang, H.C. Chou, T.-L. Citron, R. Connors, J. Moran, C. Corbett Cornelison, J. Crawford, T.M. Crites, A.T. Crumrine, M. Cukierman, A. de Haan, T. Dierickx, M. Dobbs, M.A. Duband, L. Everett, W. Fatigoni, S. Filippini, J.P. Fliescher, S. Gallicchio, J. George, E.M. Germaine, T.St. Goeckner-Wald, N. Goldfinger, D.C. Grayson, J. Gupta, N. Hall, G. Halpern, M. Halverson, N.W. Harrison, S. Henderson, S. Henning, J.W. Hildebrandt, S.R. Hilton, G.C. Holder, G.P. Holzapfel, W.L. Hrubes, J.D. Huang, N. Hubmayr, J. Hui, H. Irwin, K.D. Kang, J. Karkare, K.S. Karpel, E. Kefeli, S. Kernasovskiy, S.A. Knox, L. Kovac, J.M. Kuo, C.L. Lau, K. Lee, A.T. Leitch, E.M. Li, D. Lowitz, A. Manzotti, A. McMahon, J.J. Megerian, K.G. Meyer, S.S. Millea, M. Mocanu, L.M. Moncelsi, L. Montgomery, J. Nadolski, A. Namikawa, T. Natoli, T. Netterfield, C.B. Nguyen, H.T. Nibarger, J.P. Noble, G. Novosad, V. O’Brient, R. Ogburn, R.W. Omori, Y. Padin, S. Palladino, S. Patil, S. Prouve, T. Pryke, C. Racine, B. Reichardt, C.L. Reintsema, C.D. Richter, S. Ruhl, J.E. Saliwanchik, B.R. Schaffer, K.K. Schillaci, A. Schmitt, B.L. Schwarz, R. Sheehy, C.D. Sievers, C. Smecher, G. Soliman, A. Stark, A.A. Steinbach, B. Sudiwala, R.V. Teply, G.P. Thompson, K.L. Tolan, J.E. Tucker, C. Turner, A.D. Umiltà, C. Veach, T. Vieira, J.D. Vieregg, A.G. Wandui, A. Wang, G. Weber, A.C. Whitehorn, N. Wiebe, D.V. Willmert, J. Wong, C.L. Wu, W.L. Kimmy Yang, H. Yefremenko, V. Yoon, K.W. Young, E. Yu, C. Zeng, L. Zhang, C. Cardiff University CardiffCF10 3XQ United Kingdom SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States Kavli Institute for Particle Astrophysics and Cosmology Stanford University 452 Lomita Mall StanfordCA94305 United States Department of Physics and Astronomy University of British Columbia VancouverBCV6T 1Z1 Canada Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States NIST Quantum Devices Group 325 Broadway Mailcode 817.03 BoulderCO80305 United States Department of Physics University of Colorado BoulderCO80309 United States Department of Physics University of California BerkeleyCA94720 United States Harvard-Smithsonian Center for Astrophysics 60 Garden Street CambridgeMA02138 United States California Institute of Technology MS 249-17 1216 E. California Blvd. PasadenaCA91125 United States High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue ArgonneIL60439 United States Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States School of Physics University of Melbourne ParkvilleVIC3010 Australia Department of Physics University of Cincinnati CincinnatiOH45221 United States Jet Propulsion Laboratory PasadenaCA91109 United States Department of Physics Harvard University CambridgeMA02138 United States Minnesota Institute for Astrophysics University of Minnesota MinneapolisMN55455 United States Department of Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Physics McGill University 3600 Rue University MontrealQCH3A 2T8 Canada School of Mathematics Statistics & Computer Science University of KwaZulu-Natal

We present a constraint on the tensor-to-scalar ratio, r, derived from measurements of cosmic microwave background (CMB) polarization B-modes with "delensing," whereby the uncertainty on r contributed by the sample variance of the gravitational lensing B-modes is reduced by cross-correlating against a lensing B-mode template. This template is constructed by combining an estimate of the polarized CMB with a tracer of the projected large-scale structure. The large-scale-structure tracer used is a map of the cosmic infrared background derived from Planck satellite data, while the polarized CMB map comes from a combination of South Pole Telescope, Bicep/Keck, and Planck data. We expand the Bicep/Keck likelihood analysis framework to accept a lensing template and apply it to the Bicep/Keck data set collected through 2014 using the same parametric foreground modelling as in the previous analysis. From simulations, we find that the uncertainty on r is reduced by ∼ 10%, from σ(r)= 0.024 to 0.022, which can be compared with a ∼ 26% reduction obtained when using a perfect lensing template or if there were zero lensing B-modes. Applying the technique to the real data, the constraint on r is improved from r0.05 Copyright © 2020, The Authors. All rights reserved.

关键词： Cosmology

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Teachers and Mobile Learning Perception: Towards a Conceptual Model of Mobile Learning for Training

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Procedia - Social and Behavioral sciences 2015年 176卷 425-430页

作者： Iin Karmila Yusri Robert Goodwin Carl Mooney School of Computer science Engineering and Mathematics Flinders University Australia Computer and Networking Engineering Study Program Ujung Pandang State of Polytechnic Indonesia

Before designing and implementing a mobile learning system, it is important to ascertain the perception of future users towards mobile learning since their perception will influence their willingness and readiness to use the system. This research investigated the perception of teachers in Indonesia of mobile learning to ascertain their readiness to engage in mobile learning for training. This study conducted a survey with 308 high school teacher respondents. The results show that teachers in Indonesia had positive perception of mobile learning and were looking forward to engage in mobile learning. Financial and device issues were not obstacles for the teachers to participate in a mobile learning environment. Interestingly, the knowledge and readiness for mobile learning of teachers who taught ICT subject was lower than teachers with mathematics, science, and other subjects. Findings obtained from this study are used as a base for designing and developing a mobile learning system for ICT training for teachers in Indonesia.

关键词： teachers mobile learning perception training system

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Optimal CMB lensing reconstruction and parameter estimation with SPTpol data

arXiv

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arXiv 2020年

作者： Millea, Marius Daley, C.M. Chou, T.-L. Anderes, E. Ade, P.A.R. Anderson, A.J. Austermann, J.E. Avva, J.S. Beall, J.A. Bender, A.N. Benson, B.A. Bianchini, F. Bleem, L.E. Carlstrom, J.E. Chang, C.L. Chaubal, P. Chiang, H.C. Citron, R. Corbett Moran, C. Crawford, T.M. Crites, A.T. de Haan, T. Dobbs, M.A. Everett, W. Gallicchio, J. George, E.M. Goeckner-Wald, N. Guns, S. Gupta, N. Halverson, N.W. Henning, J.W. Hilton, G.C. Holder, G.P. Holzapfel, W.L. Hrubes, J.D. Huang, N. Hubmayr, J. Irwin, K.D. Knox, L. Lee, A.T. Li, D. Lowitz, A. McMahon, J.J. Meyer, S.S. Mocanu, L.M. Montgomery, J. Natoli, T. Nibarger, J.P. Noble, G. Novosad, V. Omori, Y. Padin, S. Patil, S. Pryke, C. Reichardt, C.L. Ruhl, J.E. Saliwanchik, B.R. Schaffer, K.K. Sievers, C. Smecher, G. Stark, A.A. Thorne, B. Tucker, C. Veach, T. Vieira, J.D. Wang, G. Whitehorn, N. Wu, W.L.K. Yefremenko, V. Department of Physics University of California BerkeleyCA94720 United States Astronomy Department University of Illinois at Urbana-Champaign 1002 W. Green Street UrbanaIL61801 United States Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Statistics University of California One Shields Avenue DavisCA95616 United States Cardiff University CardiffCF10 3XQ United Kingdom Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States NIST Quantum Devices Group 325 Broadway Mailcode 817.03 BoulderCO80305 United States Department of Physics University of Colorado BoulderCO80309 United States High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue ArgonneIL60439 United States Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States School of Physics University of Melbourne ParkvilleVIC3010 Australia Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Physics McGill University 3600 Rue University MontrealQCH3A 2T8 Canada School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Durban South Africa University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Jet Propulsion Laboratory PasadenaCA91109 United States Dunlap Institute for Astronomy & Astrophysics University of Toronto 50 St George St TorontoONM5S 3H4 Canada Department of Astronomy & Astrophysics University of Toronto 50 St George St TorontoONM5S 3H4 Canada Physics Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Canadian Institute for Advanced Research CIFAR Program in Gravity Extreme Universe TorontoONM5G 1Z8 Canada Department of Astrophysical and Pla

We perform the first simultaneous Bayesian parameter inference and optimal reconstruction of the gravitational lensing of the cosmic microwave background (CMB), using 100 deg2 of polarization observations from the SPTpol receiver on the South Pole Telescope. These data reach noise levels as low as 5.8 µK-arcmin in polarization, which are low enough that the typically used quadratic estimator (QE) technique for analyzing CMB lensing is significantly sub-optimal. Conversely, the Bayesian procedure extracts all lensing information from the data and is optimal at any noise level. We infer the amplitude of the gravitational lensing potential to be Aφ = 0.949 ±0.122 using the Bayesian pipeline, consistent with our QE pipeline result, but with 17% smaller error bars. The Bayesian analysis also provides a simple way to account for systematic uncertainties, performing a similar job as frequentist "bias hardening," and reducing the systematic uncertainty on Aφ due to polarization calibration from almost half of the statistical error to effectively zero. Finally, we jointly constrain Aφ along with AL, the amplitude of lensing-like effects on the CMB power spectra, demonstrating that the Bayesian method can be used to easily infer parameters both from an optimal lensing reconstruction and from the delensed CMB, while exactly accounting for the correlation between the two. These results demonstrate the feasibility of the Bayesian approach on real data, and pave the way for future analysis of deep CMB polarization measurements with SPT-3G, Simons Observatory, and CMB-S4, where improvements relative to the QE can reach 1.5 times tighter constraints on Aφ and 7 times lower effective lensing reconstruction noise. Copyright © 2020, The Authors. All rights reserved.

关键词： Cosmology

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Measurements of B-mode polarization of the cosmic microwave background from 500 square degrees of SPTpol data

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Physical Review D 2020年第12期101卷 122003-122003页

作者： J. T. Sayre C. L. Reichardt J. W. Henning P. A. R. Ade A. J. Anderson J. E. Austermann J. S. Avva J. A. Beall A. N. Bender B. A. Benson F. Bianchini L. E. Bleem J. E. Carlstrom C. L. Chang P. Chaubal H. C. Chiang R. Citron C. Corbett Moran T. M. Crawford A. T. Crites T. de Haan M. A. Dobbs W. Everett J. Gallicchio E. M. George A. Gilbert N. Gupta N. W. Halverson N. Harrington G. C. Hilton G. P. Holder W. L. Holzapfel J. D. Hrubes N. Huang J. Hubmayr K. D. Irwin L. Knox A. T. Lee D. Li A. Lowitz J. J. McMahon S. S. Meyer L. M. Mocanu J. Montgomery A. Nadolski T. Natoli J. P. Nibarger G. Noble V. Novosad S. Padin S. Patil C. Pryke J. E. Ruhl B. R. Saliwanchik K. K. Schaffer C. Sievers G. Smecher A. A. Stark C. Tucker K. Vanderlinde T. Veach J. D. Vieira G. Wang N. Whitehorn W. L. K. Wu V. Yefremenko Department of Astrophysical and Planetary Sciences University of Colorado Boulder Colorado 80309 USA Department of Physics University of Colorado Boulder Colorado 80309 USA Physics Department Center for Education and Research in Cosmology and Astrophysics Case Western Reserve University Cleveland Ohio 44106 USA School of Physics University of Melbourne Parkville Victoria 3010 Australia High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue Argonne Illinois 60439 USA Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Cardiff University Cardiff CF10 3XQ United Kingdom Fermi National Accelerator Laboratory MS209 P.O. Box 500 Batavia Illinois 60510 USA NIST Quantum Devices Group 325 Broadway Mailcode 817.03 Boulder Colorado 80305 USA Department of Physics University of California Berkeley California 94720 USA Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Department of Physics University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Department of Physics McGill University 3600 Rue University Montreal Quebec H3A 2T8 Canada School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Durban South Africa University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA TAPIR Walter Burke Institute for Theoretical Physics California Institute of Technology 1200 E California Boulevard Pasadena California 91125 USA California Institute of Technology MS 249-17 1216 E. California Boulevard Pasadena California 91125 USA Physics Division Lawrence Berkeley National Laboratory Berkeley California 94720 USA Canadian Institute for Advanced Research CIFAR Program in Gravity and the Extreme Universe Toronto Ontario M5G 1Z8 Canada Harvey Mudd College 301 Platt

We report a B-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope. This work uses 500 deg2 of SPTpol data, a five-fold increase over the last SPTpol B-mode release. As a result, the bandpower uncertainties have been reduced by more than a factor of two, and the measurement extends to lower multipoles: 52<ℓ<2301. Data from both 95 and 150 GHz are used, allowing for three cross-spectra: 95 GHz × 95 GHz, 95 GHz × 150 GHz, and 150 GHz × 150 GHz. B-mode power is detected at very high significance; we find P(BB<0)=5.8×10−71, corresponding to a 18.1σ detection of power. With a prior on the galactic dust from Planck, WMAP and BICEP2/Keck observations, the SPTpol B-mode data can be used to set an upper limit on the tensor-to-scalar ratio, r<0.44 at 95% confidence (the expected 1σ constraint on r given the measurement uncertainties is 0.22). We find the measured B-mode power is consistent with the Planck best-fit ΛCDM model predictions. Scaling the predicted lensing B-mode power in this model by a factor Alens, the data prefer Alens=1.17±0.13. These data are currently the most precise measurements of B-mode power at ℓ>320.

关键词： Cosmic microwave background Cosmological parameters Inflation Primordial magnetic fields

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Searching for Anisotropic Cosmic Birefringence with Polarization Data from SPTpol

arXiv

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arXiv 2020年

作者： Bianchini, F. Wu, W.L.K. Ade, P.A.R. Anderson, A.J. Austermann, J.E. Avva, J.S. Balkenhol, L. Baxter, E. Beall, J.A. Bender, A.N. Benson, B.A. Bleem, L.E. Carlstrom, J.E. Chang, C.L. Chaubal, P. Chiang, H.C. Chou, T.L. Citron, R. Moran, C. Corbett Crawford, T.M. Crites, A.T. Haan, T. de Dobbs, M.A. Everett, W. Gallicchio, J. George, E.M. Gilbert, A. Gupta, N. Halverson, N.W. Henning, J.W. Hilton, G.C. Holder, G.P. Holzapfel, W.L. Hrubes, J.D. Huang, N. Hubmayr, J. Irwin, K.D. Knox, L. Lee, A.T. Li, D. Lowitz, A. Manzotti, A. McMahon, J.J. Meyer, S.S. Millea, M. Mocanu, L.M. Montgomery, J. Nadolski, A. Natoli, T. Nibarger, J.P. Noble, G. Novosad, V. Omori, Y. Padin, S. Patil, S. Pryke, C. Reichardt, C.L. Ruhl, J.E. Saliwanchik, B.R. Schaffer, K.K. Sievers, C. Simard, G. Smecher, G. Stark, A.A. Story, K.T. Tucker, C. Vanderlinde, K. Veach, T. Vieira, J.D. Wang, G. Whitehorn, N. Yefremenko, V. School of Physics University of Melbourne ParkvilleVIC3010 Australia Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Cardiff University CardiffCF10 3XQ United Kingdom Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States NIST Quantum Devices Group 325 Broadway Mailcode 817.03 BoulderCO80305 United States Department of Physics University of Colorado BoulderCO80309 United States Department of Physics University of California BerkeleyCA94720 United States Institute for Astronomy University of Hawai’i 2680 Woodlawn Drive HonoluluHI96822 United States High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue ArgonneIL60439 United States Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Physics McGill University 3600 Rue University MontrealQCH3A 2T8 Canada School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Durban South Africa Department of Physics University of Chicago ChicagoIL60637 United States University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States TAPIR Walter Burke Institute for Theoretical Physics California Institute of Technology 1200 E California Blvd PasadenaCA91125 United States California Institute of Technology MS 249-17 1216 E. California Blvd. PasadenaCA91125 United States Physics Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Canadian Institute for Advanced Research CIFAR Program in Gravity and the Extreme Universe TorontoONM5G 1Z8 Canada Department of Astrophysical and Planetary Sciences University of Colorado BoulderCO80309 U

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Searching for anisotropic cosmic birefringence with polarization data from SPTpol

引用

Physical Review D 2020年第8期102卷 083504-083504页

作者： F. Bianchini W. L. K. Wu P. A. R. Ade A. J. Anderson J. E. Austermann J. S. Avva L. Balkenhol E. Baxter J. A. Beall A. N. Bender B. A. Benson L. E. Bleem J. E. Carlstrom C. L. Chang P. Chaubal H. C. Chiang T. L. Chou R. Citron C. Corbett Moran T. M. Crawford A. T. Crites T. de Haan M. A. Dobbs W. Everett J. Gallicchio E. M. George A. Gilbert N. Gupta N. W. Halverson J. W. Henning G. C. Hilton G. P. Holder W. L. Holzapfel J. D. Hrubes N. Huang J. Hubmayr K. D. Irwin L. Knox A. T. Lee D. Li A. Lowitz A. Manzotti J. J. McMahon S. S. Meyer M. Millea L. M. Mocanu J. Montgomery A. Nadolski T. Natoli J. P. Nibarger G. Noble V. Novosad Y. Omori S. Padin S. Patil C. Pryke C. L. Reichardt J. E. Ruhl B. R. Saliwanchik K. K. Schaffer C. Sievers G. Simard G. Smecher A. A. Stark K. T. Story C. Tucker K. Vanderlinde T. Veach J. D. Vieira G. Wang N. Whitehorn V. Yefremenko School of Physics University of Melbourne Parkville Victoria 3010 Australia Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Cardiff University Cardiff CF10 3XQ United Kingdom Fermi National Accelerator Laboratory MS209 P.O. Box 500 Batavia Illinois 60510 USA NIST Quantum Devices Group 325 Broadway Mailcode 817.03 Boulder Colorado 80305 USA Department of Physics University of Colorado Boulder Colorado 80309 USA Department of Physics University of California Berkeley California 94720 USA Institute for Astronomy University of Hawai’i 2680 Woodlawn Drive Honolulu Hawaii 96822 USA High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue Argonne Illinois 60439 USA Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Department of Physics University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Department of Physics McGill University 3600 Rue University Montreal Quebec H3A 2T8 Canada School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Durban South Africa Department of Physics University of Chicago Chicago Illinois 60637 USA University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA TAPIR Walter Burke Institute for Theoretical Physics California Institute of Technology 1200 E. California Blvd. Pasadena California 91125 USA California Institute of Technology MS 249-17 1216 E. California Blvd. Pasadena California 91125 USA Physics Division Lawrence Berkeley National Laboratory Berkeley California 94720 USA Canadian Institute for Advanced Research CIFAR Program in Gravity and the Extreme Universe Toronto Ontario M5G 1Z8 Canada Department of Astrophysical and Planetary Sciences University of Colorado Boulder Colorado 80309 USA Harvey Mudd

We present a search for anisotropic cosmic birefringence in 500 deg2 of southern sky observed at 150 GHz with the SPTpol camera on the South Pole Telescope. We reconstruct a map of cosmic polarization rotation anisotropies using higher-order correlations between the observed cosmic microwave background (CMB) E and B fields. We then measure the angular power spectrum of this map, which is found to be consistent with zero. The nondetection is translated into an upper limit on the amplitude of the scale-invariant cosmic rotation power spectrum, L(L+1)CLαα/2π<0.10×10−4 rad2 (0.033 deg2, 95% C.L.). This upper limit can be used to place constraints on the strength of primordial magnetic fields, B1 Mpc<17 nG (95% C.L.), and on the coupling constant of the Chern-Simons electromagnetic term gaγ<4.0×10−2/HI (95% C.L.), where HI is the inflationary Hubble scale. For the first time, we also cross-correlate the CMB temperature fluctuations with the reconstructed rotation angle map, a signal expected to be nonvanishing in certain theoretical scenarios, and find no detectable signal. We perform a suite of systematics and consistency checks and find no evidence for contamination.

关键词： Cosmic microwave background Primordial magnetic fields

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