From apohl at uni-bremen.de Mon Jul 4 13:47:06 2022 From: apohl at uni-bremen.de (Anke POHL) Date: Mon, 4 Jul 2022 13:47:06 +0200 Subject: [BODS] Luca Marchese, Jul 28th, 3:30 pm CEST Message-ID: <87e8bfbb-e265-b2b8-bb83-ac9b05f3c958@uni-bremen.de> Dear all, For the next talk in the Bremen Online Dynamics Seminar (BODS) we welcome: Speaker: Luca Marchese (U Bologna) Date and time: Monday, Jul 18th, 2022, 3:30-4:30 pm CEST (+ ca. 15 min Q&A) Link: https://uni-bremen.zoom.us/j/4528023413?pwd=ZUFqR0xXM0JMNU1hcnlQQnNmMlhEQT09 For full link information see below. **** Title: Transfer operators and dimension of bad sets for non-uniform fuchsian lattices. Abstract: The set of badly approximable real numbers admits an exhaustion in sets Bad(c) with c>0, whose dimension goes to zero as c goes to zero. D. Hensley computed the asymptotic for the dimension up to the first order in c, via an estimate for the dimension of the set of real numbers whose continued fraction has partial quotiens bounded by a fixed parameter. We consider diophantine approximations by parabolic fixed points of any non-uniform lattice in PSL(2,R) and the corresponding notion of badly approximable real numbers. We compute the dimension of the set of such points up to the first order in c>0, via the thermodynamic method of Ruelle and Bowen. Geometric good approximations are related to a notion of bounded partial quotients for the Bowen-Series expansion. This gives a family of Cantor sets and associated quasi-compact transfer operators, with simple and positive maximal eigenvalue. Then perturbative analysis of spectra applies. **** For the growing list of future talks please refer to researchseminars.org/seminar/BODS Looking forward to seeing many of you there, Anke **** Join Zoom Meeting https://uni-bremen.zoom.us/j/4528023413?pwd=ZUFqR0xXM0JMNU1hcnlQQnNmMlhEQT09 Meeting ID: 452 802 3413 Passcode: Wers34Howk One tap mobile +13017158592,,4528023413#,,,,*7864803179# US (Washington DC) +13126266799,,4528023413#,,,,*7864803179# US (Chicago) Dial by your location +1 301 715 8592 US (Washington DC) +1 312 626 6799 US (Chicago) +1 346 248 7799 US (Houston) +1 669 900 6833 US (San Jose) +1 929 205 6099 US (New York) +1 253 215 8782 US (Tacoma) Meeting ID: 452 802 3413 Passcode: 7864803179 Find your local number: https://uni-bremen.zoom.us/u/acq8lt6pXs Join by SIP 4528023413 at zoomcrc.com Join by H.323 162.255.37.11 (US West) 162.255.36.11 (US East) 213.19.144.110 (Amsterdam Netherlands) 213.244.140.110 (Germany) Meeting ID: 452 802 3413 Passcode: 7864803179 -- Prof. Dr. Anke Pohl University of Bremen Department 3 - Mathematics Institute for Dynamical Systems Bibliothekstr. 5 28359 Bremen Germany http://user.math.uni-bremen.de/apohl/ Telefone: +49-421-218-63661 Email: apohl at uni-bremen.de Office: MZH 4150 From apohl at uni-bremen.de Mon Jul 4 14:57:15 2022 From: apohl at uni-bremen.de (Anke POHL) Date: Mon, 4 Jul 2022 14:57:15 +0200 Subject: [BODS] Luca Marchese, Jul 18th, 3:30 pm CEST Message-ID: <1f9015db-deae-8326-ff79-29a812f59c30@uni-bremen.de> Dear all, in my previous email, the date in the subject had a typo. It should read 18th, as in the mail text. The talk is in two weeks. For everyone's convenience, here is the corrected version in full. Best Anke Dear all, For the next talk in the Bremen Online Dynamics Seminar (BODS) we welcome: Speaker: Luca Marchese (U Bologna) Date and time: Monday, Jul 18th, 2022, 3:30-4:30 pm CEST (+ ca. 15 min Q&A) Link: https://uni-bremen.zoom.us/j/4528023413?pwd=ZUFqR0xXM0JMNU1hcnlQQnNmMlhEQT09 For full link information see below. **** Title: Transfer operators and dimension of bad sets for non-uniform fuchsian lattices. Abstract: The set of badly approximable real numbers admits an exhaustion in sets Bad(c) with c>0, whose dimension goes to zero as c goes to zero. D. Hensley computed the asymptotic for the dimension up to the first order in c, via an estimate for the dimension of the set of real numbers whose continued fraction has partial quotiens bounded by a fixed parameter. We consider diophantine approximations by parabolic fixed points of any non-uniform lattice in PSL(2,R) and the corresponding notion of badly approximable real numbers. We compute the dimension of the set of such points up to the first order in c>0, via the thermodynamic method of Ruelle and Bowen. Geometric good approximations are related to a notion of bounded partial quotients for the Bowen-Series expansion. This gives a family of Cantor sets and associated quasi-compact transfer operators, with simple and positive maximal eigenvalue. Then perturbative analysis of spectra applies. **** For the growing list of future talks please refer to researchseminars.org/seminar/BODS Looking forward to seeing many of you there, Anke **** Join Zoom Meeting https://uni-bremen.zoom.us/j/4528023413?pwd=ZUFqR0xXM0JMNU1hcnlQQnNmMlhEQT09 Meeting ID: 452 802 3413 Passcode: Wers34Howk One tap mobile +13017158592,,4528023413#,,,,*7864803179# US (Washington DC) +13126266799,,4528023413#,,,,*7864803179# US (Chicago) Dial by your location +1 301 715 8592 US (Washington DC) +1 312 626 6799 US (Chicago) +1 346 248 7799 US (Houston) +1 669 900 6833 US (San Jose) +1 929 205 6099 US (New York) +1 253 215 8782 US (Tacoma) Meeting ID: 452 802 3413 Passcode: 7864803179 Find your local number: https://uni-bremen.zoom.us/u/acq8lt6pXs Join by SIP 4528023413 at zoomcrc.com Join by H.323 162.255.37.11 (US West) 162.255.36.11 (US East) 213.19.144.110 (Amsterdam Netherlands) 213.244.140.110 (Germany) Meeting ID: 452 802 3413 Passcode: 7864803179 -- Prof. Dr. Anke Pohl University of Bremen Department 3 - Mathematics Institute for Dynamical Systems Bibliothekstr. 5 28359 Bremen Germany http://user.math.uni-bremen.de/apohl/ Telefone: +49-421-218-63661 Email: apohl at uni-bremen.de Office: MZH 4150 From apohl at uni-bremen.de Sun Jul 17 17:50:49 2022 From: apohl at uni-bremen.de (Anke POHL) Date: Sun, 17 Jul 2022 17:50:49 +0200 Subject: [BODS] Tomorrow: Luca Marchese, Jul 18th, 3:30 pm CEST Message-ID: <08b5a16f-dc9a-1a8b-58da-77a46f7b5080@uni-bremen.de> Dear all, For the next talk in the Bremen Online Dynamics Seminar (BODS) we welcome: Speaker: Luca Marchese (U Bologna) Date and time: Monday, Jul 18th, 2022, 3:30-4:30 pm CEST (+ ca. 15 min Q&A) Link: https://uni-bremen.zoom.us/j/4528023413?pwd=ZUFqR0xXM0JMNU1hcnlQQnNmMlhEQT09 For full link information see below. **** Title: Transfer operators and dimension of bad sets for non-uniform fuchsian lattices. Abstract: The set of badly approximable real numbers admits an exhaustion in sets Bad(c) with c>0, whose dimension goes to zero as c goes to zero. D. Hensley computed the asymptotic for the dimension up to the first order in c, via an estimate for the dimension of the set of real numbers whose continued fraction has partial quotiens bounded by a fixed parameter. We consider diophantine approximations by parabolic fixed points of any non-uniform lattice in PSL(2,R) and the corresponding notion of badly approximable real numbers. We compute the dimension of the set of such points up to the first order in c>0, via the thermodynamic method of Ruelle and Bowen. Geometric good approximations are related to a notion of bounded partial quotients for the Bowen-Series expansion. This gives a family of Cantor sets and associated quasi-compact transfer operators, with simple and positive maximal eigenvalue. Then perturbative analysis of spectra applies. **** For the growing list of future talks please refer to researchseminars.org/seminar/BODS Looking forward to seeing many of you there, Anke **** Join Zoom Meeting https://uni-bremen.zoom.us/j/4528023413?pwd=ZUFqR0xXM0JMNU1hcnlQQnNmMlhEQT09 Meeting ID: 452 802 3413 Passcode: Wers34Howk One tap mobile +13017158592,,4528023413#,,,,*7864803179# US (Washington DC) +13126266799,,4528023413#,,,,*7864803179# US (Chicago) Dial by your location +1 301 715 8592 US (Washington DC) +1 312 626 6799 US (Chicago) +1 346 248 7799 US (Houston) +1 669 900 6833 US (San Jose) +1 929 205 6099 US (New York) +1 253 215 8782 US (Tacoma) Meeting ID: 452 802 3413 Passcode: 7864803179 Find your local number: https://uni-bremen.zoom.us/u/acq8lt6pXs Join by SIP 4528023413 at zoomcrc.com Join by H.323 162.255.37.11 (US West) 162.255.36.11 (US East) 213.19.144.110 (Amsterdam Netherlands) 213.244.140.110 (Germany) Meeting ID: 452 802 3413 Passcode: 7864803179 -- Prof. Dr. Anke Pohl University of Bremen Department 3 - Mathematics Institute for Dynamical Systems Bibliothekstr. 5 28359 Bremen Germany http://user.math.uni-bremen.de/apohl/ Telefone: +49-421-218-63661 Email: apohl at uni-bremen.de Office: MZH 4150 From apohl at uni-bremen.de Mon Jul 18 12:16:25 2022 From: apohl at uni-bremen.de (Anke POHL) Date: Mon, 18 Jul 2022 12:16:25 +0200 Subject: [BODS] Today: Luca Marchese, Jul 18th, 3:30 pm CEST Message-ID: Dear all, For the next talk in the Bremen Online Dynamics Seminar (BODS) we welcome: Speaker: Luca Marchese (U Bologna) Date and time: Monday, Jul 18th, 2022, 3:30-4:30 pm CEST (+ ca. 15 min Q&A) Link: https://uni-bremen.zoom.us/j/4528023413?pwd=ZUFqR0xXM0JMNU1hcnlQQnNmMlhEQT09 For full link information see below. **** Title: Transfer operators and dimension of bad sets for non-uniform fuchsian lattices. Abstract: The set of badly approximable real numbers admits an exhaustion in sets Bad(c) with c>0, whose dimension goes to zero as c goes to zero. D. Hensley computed the asymptotic for the dimension up to the first order in c, via an estimate for the dimension of the set of real numbers whose continued fraction has partial quotiens bounded by a fixed parameter. We consider diophantine approximations by parabolic fixed points of any non-uniform lattice in PSL(2,R) and the corresponding notion of badly approximable real numbers. We compute the dimension of the set of such points up to the first order in c>0, via the thermodynamic method of Ruelle and Bowen. Geometric good approximations are related to a notion of bounded partial quotients for the Bowen-Series expansion. This gives a family of Cantor sets and associated quasi-compact transfer operators, with simple and positive maximal eigenvalue. Then perturbative analysis of spectra applies. **** For the growing list of future talks please refer to researchseminars.org/seminar/BODS Looking forward to seeing many of you there, Anke **** Join Zoom Meeting https://uni-bremen.zoom.us/j/4528023413?pwd=ZUFqR0xXM0JMNU1hcnlQQnNmMlhEQT09 Meeting ID: 452 802 3413 Passcode: Wers34Howk One tap mobile +13017158592,,4528023413#,,,,*7864803179# US (Washington DC) +13126266799,,4528023413#,,,,*7864803179# US (Chicago) Dial by your location +1 301 715 8592 US (Washington DC) +1 312 626 6799 US (Chicago) +1 346 248 7799 US (Houston) +1 669 900 6833 US (San Jose) +1 929 205 6099 US (New York) +1 253 215 8782 US (Tacoma) Meeting ID: 452 802 3413 Passcode: 7864803179 Find your local number: https://uni-bremen.zoom.us/u/acq8lt6pXs Join by SIP 4528023413 at zoomcrc.com Join by H.323 162.255.37.11 (US West) 162.255.36.11 (US East) 213.19.144.110 (Amsterdam Netherlands) 213.244.140.110 (Germany) Meeting ID: 452 802 3413 Passcode: 7864803179 -- Prof. Dr. Anke Pohl University of Bremen Department 3 - Mathematics Institute for Dynamical Systems Bibliothekstr. 5 28359 Bremen Germany http://user.math.uni-bremen.de/apohl/ Telefone: +49-421-218-63661 Email: apohl at uni-bremen.de Office: MZH 4150