Outline
DOI: 10.7494/opmath.2004.24.1.123 ISSN: 1232-9274
Corona theorem and isometries
Krzysztof RudolThe aim of this note is to discuss a new operator theory approach to Corona Problem. An equivalent operator problem invariant under unitary equivalence is stated. The related condition involves certain joint spectra of commuting subnormal operators. A special case leading to isometries is studied. As a result one obtains a relatively short proof of Corona Theorem for a wide class of domains in the plane, where Marshall's Theorem on the approximation by inner functions holds.
More from our Archive
- DOI: 10.54120/jost.v25i1.dc6o4846 2026DSRP-484Derek Cabrera, Laura Cabrera
- DOI: 10.1108/978-1-83742-372-9 2026A Comparative Handbook of Redesigned Sales and Marketing Management in the Digital EraAuthors not available
- DOI: 10.54120/jost.v25i1.dc6mcnl6 2026Measuring Context as Structural Organization in Natural LanguageDerek Cabrera, Laura Cabrera
- DOI: 10.1093/cid/ciag520 2026Surveillance Data Use Through the Fleming Fund: Informing Action on Antimicrobial Resistance in Low- and Middle-Income CountriesArchie Drake, Alesia Ofori, Amy Rahmadanti, Ankur Gupta-Wright, Areeya Disratthakit, Ayodele Majekodunmi, Benjamin Kissi Sasu, N Claire Gordon, Claudia Parry, Collins Mitambo, Deborah Nanjebe, Desrina Sitompul, Didem Torumkuney, Evelyn Wesangula, Freddy Eric Kitutu, Heidi Hopkins, Jacob Wildfire, Japheth A Opintan, Jennifer Armitage, Joseph Sam Kanu, Kate Macintyre, Kriti Khurana, Lamiaa Shehata, Manish Pathak, Megha Raj Banjara, Milena von und zur Mühlen, Muhammad Taimoor Kayani, Muhammad Usman Zaheer, Mwapu Ndahi, Nandini Shetty, Nicholas Feasey, Nigel French, Nimesh Poudyal, Nure Alam Siddiky, Paul Turner, Pem Chuki, Qadeer Ahsan, Rebecca Maudling, Ritu Amatya, Satyajit Sarkar, Syed Abbas, Tamalee Roberts, Tauqeer Mustafa, Tim Shorten, Titha Dzowela, Toby Leslie, Tochi Okwor, Yu Nandar Aung
- DOI: 10.1093/cid/ciag500 2026Fleming Fund Implementation in Kenya: What Have We Learned About Strengthening One Health Antimicrobial Resistance Surveillance for Decision-making?Evelyn Wesangula, Nkatha Gitonga, Emmanuel Tanui, Romona Ndanyi, Susan Githii, Bridgit Syombua Muasa, Eunice Omondi, Eric M Fèvre, Dishon M Muloi, Ali Kassim, Josiah Mwenda, Christine Minoo Mbindyo, Irungu John Kamau, Loice Achieng Ombajo, Gunturu Revathi, Veronica Chuchu, Anafi Mataka, Moctar M M Mouiche, Arshnee Moodley, Stanley Fenwick, Deborah Nanjebe, Lillian Bibangamba, Patrick Mubangizi, Toby Leslie, John A Crump, Zulfiqar Ahmed Bhutta, Tim Walsh, Kate Macintyre, Rebecca Maudling, Solomon Mugabe, Raheelah Ahmad, Lamiaa Shehata, Tim Shorten
- DOI: 10.1093/cid/ciag497 2026Generating Actionable Data From Antimicrobial Resistance Surveillance: Insights From the Fleming Fund's International ExperienceAnkur Gupta-Wright, Suliat Yetunde Adeleke, Victoria Adetunji, Qadeer Ahsan, Ritu Amatya, Ben Amos, Brian Asare, Sorie I O Bangura, Cyril Buhler, Nicholas Feasey, N Claire Gordon, Heidi Hopkins, Freddy Eric Kitutu, Toby Leslie, Ibrahima Lo, Seynabou Lo, Ayodele Majekodunmi, Rebecca Maudling, Ntombi B Mudenda, Victor Moses Musyoki, Deborah Nanjebe, Tessa Oakley, Manish Pathak, Tamalee Roberts, Lamiaa Shehata, Tim Shorten, Nure Alam Siddiky, John Stelling, Muhammad Taimoor, May Soe Thwe, Shawn Ting, Didem Torumkuney, Paul Turner, Jacob Wildfire, Timothy David Worth
- DOI: 10.1098/rsta.2025.0271 2026Tropospheric Ozone Assessment Report II: Stratosphere–troposphere exchange of ozoneJames Keeble, Paul T. Griffiths, Marta Abalos, Dimitris Akritidis, Samuel Bartusek, Owen R. Cooper, Qiang Fu, Michaela I. Hegglin, Fernando Iglesias-Suarez, Gerbrand Koren, Oindrila Nath, Michael Prather, Davide Putero, Chaitri Roy, Bhupendra Bahadur Singh, Andreas Stohl, Katharina Blazytko, Thomas Trickl, Oliver Wild, Prodromos Zanis
- DOI: 10.1098/rsta.2025.0274 2026Tropospheric Ozone Assessment Report II: Past and present tropospheric ozone using satellite observationsDaan Hubert, Kazuyuki Miyazaki, Gaëlle Dufour, Elyse A. Pennington, Viktoria F. Sofieva, Carlo Arosio, Brice Barret, Anne Boynard, Melanie Coldewey-Egbers, Juan Cuesta, Klaus-Peter Heue, Arno Keppens, Natalya A. Kramarova, Jean-Christopher Lambert, Diego Loyola, Andrea P. Orfanoz-Cheuquelaf, Richard Siddans, Roeland Van Malderen, J. Pepijn Veefkind, Catherine Wespes, Jerry R. Ziemke
- DOI: 10.1093/cid/ciag517 2026Antimicrobial Resistance and One Health: Lessons on One Health Governance and Implementation from the Fleming FundSyed Shahid Abbas, Rebecca Maudling, Antoine Andremont, Yu Nandar Aung, Regina Ama Banu, Manisha Bista, Roderick M Card, Eileen Chappell, Etienne Chevanne, Mauricio Coppo, Stanley Fenwick, Nigel French, William H Gaze, Joanna McKenzie, Noah Obeng-Nkrumah, Garima Singh, Desrina Sitompul, Mark Stevenson, Shawn Ting, Jaap A Wagenaar, Evelyn Wesangula, Anke Wiethoelter, Timothy Worth, Qadeer Ahsan, Winfred Christine Amia, Mathias Ayuk Besong, Eric Sampane Donkor, James Fairfax, Heidi Hopkins, Easrat Jahan, Anis Karuniawati, Toby Leslie, Ayodele Majekodunmi, Arshnee Moodley, Athina Papadopoulou, Shahriar Rizvi, Tim Shorten, Steven Uggowitzer, Tom Weaver, Muhammad Usman Zaheer
- DOI: 10.14245/ns.26520656.0328 2026Erector Spinae Plane Block Combined With Local Infiltration Analgesia for Posterior Lumbar Interbody Fusion: Prospective, Double-Blind, Randomized Controlled TrialMeng-Yu Fu, Feng Zhao, Yi-Heng Song, Rao-Rao Zhou, Wei-Ping Ren, Yu-Kai Liang, Jun Xi, Peng-Cui Li, Xiao-Chun Wei, Shao-Wei Wang, Lu Li