Wojciechowski, Radoslaw

Professor and Chair
Mathematics and Computer Science

Phone: 718-262-3855
Office Location: AC-2C07E
RWojciechowski@york.cuny.edu
http://scholar.google.com/citations?user=_C2YWg4AAAAJ&hl=en

Office Hours
Tuesday/Thursday	4:00-5:00 pm
Wednesday	2:00-4:00 pm

Areas of Expertise

Heat equation and heat kernels on infinite graphs
Spectral graph theory
Connections between manifolds and graphs

Books in Field Of Expertise

Matthias Keller, Daniel Lenz and Radoslaw K. Wojciechowski. Graphs and discrete Dirichlet spaces. Grundlehren der mathematischen Wissenschaften, vol. 358: Springer, 2021. 682 pp.

Matthias Keller, Daniel Lenz and Radoslaw K. Wojciechowski (editors). Analysis and geometry on graphs and manifolds (conference proceedings). London Mathematical Society Lecture Notes, Vol. 461: Cambridge University Press, 2020. 492 pp.

Articles in Field Of Expertise

Davide Bianchi, Alberto G. Setti and Radoslaw K. Wojciechowski. "The generalized porous medium equation on graphs: existence and uniqueness of solutions with ℓ1 data." Calculus of Variations and Partial Differential Equations. 61, no. 5 2022: 42 pp.

Radoslaw K. Wojciechowski. "Stochastic completeness of graphs: bounded Laplacians, intrinsic metrics, volume growth and curvature." Journal of Fourier Analysis and Applications Appl.. 27, no. 2 2021: 45 pp.

Bobo Hua, Jun Masamune and Radoslaw K. Wojciechowski. "Essential self-adjointness and the L^2 Liouville property." Journal of Fourier Analysis and Applications. 27, no. 2 2021: 27 pp.

Bobo Hua, Florentin Münch, Radoslaw K. Wojciechowski. "Coverings and the heat equation on graphs: stochastic incompleteness, the Feller property and uniform transience." Transactions of the American Mathematical Society. 372, no. 7 2019: 5123-5151.

Florentin Münch, Radoslaw K. Wojciechowski. "Ollivier Ricci curvature for general graph Laplacians: Heat equation, Laplacian comparison, non-explosion and diameter bounds." Advances in Mathematics. 356, 106759 2019: 45 pp.

Matthias Keller, Daniel Lenz, Marcel Schmidt, Radosław K. Wojciechowski. "Note on uniformly transient graphs." Revista Matemática Iberoamericana. 33, no. 3, 2017: 831-860.

Radoslaw K. Wojciechowski. "The Feller property for graphs." Transactions of the American Mathematical Society. 369, no. 6, 2017: 4415-4431.

Matthias Keller, Daniel Lenz, Hendrik Vogt, Radoslaw Wojciechowski. "Note on basic features of large time behaviour of heat kernels." Journal für die reine und angewandte Mathematik (Crelle's Journal). 708, 2015: 73-95.

Agelos Georgakopoulos, Sebastian Haeseler, Matthias Keller, Daniel Lenz, Radosław K. Wojciechowski. "Graphs of finite measure." Journal de Mathématiques Pures et Appliquées. 103, no. 5, 2015: 1093-1131.

Frank Bauer, Matthias Keller, Radosław K. Wojciechowski. "Cheeger inequalities for unbounded graph Laplacians." Journal of the European Mathematical Society (JEMS). 17, no. 2, 2015: 259-271.

Sebastian Haeseler, Matthias Keller, Radoslaw K. Wojciechowski. "Volume growth and bounds for the essential spectrum for Dirichlet forms." Journal of the London Mathematical Society (2). 88, 2013: 883-898.

Xueping Huang, Matthias Keller, Jun Masamune, Radoslaw K. Wojciechowski. "A note on self-adjoint extensions of the Laplacian on weighted graphs." Journal of Functional Analysis. 265, no. 8, 2013: 1556-1578.

Matthias Keller, Daniel Lenz, Radoslaw K. Wojciechowski. "Volume growth, spectrum and stochastic completeness of infinite graphs." Mathematische Zeitschrift. 274, no. 3-4, 2013: 905-932.

Sebastian Haeseler, Matthias Keller, Daniel Lenz, Radoslaw Wojciechowski. "Laplacians on infinite graphs: Dirichlet and Neumann boundary conditions." Journal of Spectral Theory. 2, no. 4, 2012: 397-432.

Radoslaw K. Wojciechowski. "Heat kernel and essential spectrum of infinite graphs." Indiana University Mathematics Journal. 58, no. 3, 2009: 1419-1441.

Refereed Proceedings in Field Of Expertise

Radoslaw Krzysztof Wojciechowski. "Stochastically incomplete manifolds and graphs." Random walks, boundaries and spectra, Progr. Probab., Birkhauser/Springer Basel AG, Basel. vol. 64 2011: 163-179.

Non Refereed Proceedings in Field Of Expertise

Radoslaw K. Wojciechowski. "Essential self-adjointness of the Laplacian on graphs: stability and Liouville properties." Mini-Workshop: Geometry, Dynamics and Spectrum of Operators on Discrete Spaces in Oberwolfach Reports. 2021: .

Radoslaw K. Wojciechowski. "Aspects of the Feller Property on Graphs." Mini-Workshop: Discrete p-Laplacians: Spectral Theory and Variational Methods in Mathematics and Computer Science in Oberwolfach Reports. 2015: .

Presented Papers, Lectures, and Exhibitions and Performances

" The Neumann semigroup via exhaustion " July 17, 2023: 26th Internet Seminar “Graphs and Discrete Dirichlet Spaces” Final Workshop, Wuppertal, Germany.

" Essential self-adjointness of the Laplacian on graphs " July 14, 2022: Seminar, DiSAT - Sezione di Matematica Universita' dell'Insubria - Como, Como, Italy.

" Graphs and discrete Dirichlet spaces " April 27, 2022: Seminar on "Functional Analysis, Operator Theory and Dynamical Systems," Jena, Potsdam and Leipzig Universities (virtual seminar).

" Graphs and discrete Dirichlet spaces " February 1, 2022: Seminar on "Geometric analysis," Bielefeld University (online meeting).

" Graphs and discrete Dirichlet spaces " June 25, 28, 29 (3 lectures), 2021: Seminar, DiSAT - Sezione di Matematica Universita' dell'Insubria - Como, Como, Italy.

" Stochastic completeness of graphs: curvature and volume growth " June 23 (moved to the 24th), 2021: 8th European Congress of Mathematics, Minisymposium on "Variational methods and equations on graphs" in Portorož, Slovenia (online meeting).

" Essential self-adjointness of the Laplacian on weighted graphs: stability and characterizations " May 26, 2021: Conference "Probability and analysis 2021," Session on "Schrodinger operators on graphs and manifolds," Wroclaw University, Poland (online meeting).

" Essential self-adjointness of the Laplacian on weighted graphs: Liouville properties, stability and characterizations " January 27, 2021: Seminar on "Functional analysis and dynamical systems," Leipzig University, Germany (online meeting).

" Essential self-adjointness of the Laplacian on weighted graphs: stability and Liouville properties " January 4, 2021: Oberwolfach Workshop on "Geometry, Dynamics and Spectrum of Operators on Discrete Spaces" (online meeting).

" The heat equation on graphs: unbounded Laplacians, stochastic completeness, intrinsic metrics and volume growth " June 21, 2020: Virtual joint seminar organized by Fudan University, Nanjing University of Information Science and Technology, and The University of Science and Technology of China.

" The Feller property, uniform transience and coverings of graphs " June 8, 2018: Seminar, DiSAT - Sezione di Matematica Universita' dell'Insubria - Como, Como, Italy.

" Some properties of the heat equation on graphs " April 5, 2018: Lunch Colloquium at the Technical University of Denmark, Copenhagen, Denmark.

" Some properties of the heat equation on graphs " March 22, 2018: One Day Workshop "Nonlocal Models in Analysis and Probability," Friedrich Schiller University of Jena, Germany.

" Stochastic incompleteness of graphs - ten years after " January 26, 2018: Explorations in Geometric Analysis - Discrete and Continuous, A Conference in Honor of Józef Dodziuk's Seventieth Birthday, the Graduate Center, CUNY.

" Explorations in Geometric Analysis - Discrete and Continuous (co-organizer) " January 25 and 26, 2018: A Conference in Honor of Józef Dodziuk's Seventieth Birthday (co-organizer with Ara Basmajian, Jeff McGowan and Mahmoud Zeinelian), The Graduate Center, CUNY.

" The heat equation on graphs: stochastic incompleteness, the Feller property and uniform transience (two lectures) " December 21, 2017: Discrete Geometric Structures Seminar, Hokkaido University.

" The Dirichlet problem at infinity for weighted graphs " November 4, 2017: International Conference "Global properties in potential theory of continuous and discrete spaces," Hokkaido University, Sapporo, Japan.

" The heat equation on graphs: stochastic incompleteness, the Feller property and uniform transience (two talks) " October 12 and 24, 2017: Fudan University, Shanghai, China.

" The heat equation on graphs: stochastic incompleteness, the Feller property and uniform transience " October 18, 2017: University of Science and Technology of China, Hefei, China.

" Ollivier Ricci curvature and the heat equation " September 21, 2017: International Conference “Analysis and PDEs on Manifolds,” Nankai University, Tianjin, China.

" Analysis and Geometry on Graphs and Manifolds (co-organizer) " July 31 to August 4, 2017: International Conference at the University of Potsdam, Germany (co-organizer with Matthias Keller and Daniel Lenz).

" Ollivier Ricci curvature for general graph Laplacians " June 17, 2017: 6th Cornell Conference on Analysis, Probability, and Mathematical Physics on Fractals.

" Spectral theory of the Laplacian on infinite weighted graphs " April 7, 2017: Mathematical Physics, Fourier Analysis, and Applications Seminar, Graduate Center, CUNY.

" The Feller property and uniform transience " March 22, 2017: International Conference on "Dirichlet Forms and their Geometry," Tohoku University, GSIS, Sendai, Japan.

" Some applications of intrinsic metrics to spectral graph theory " October 9, 2016: AMS Sectional Meeting Special Session on "Analysis on Graphs and Spectral Graph Theory," University of Denver.

" Uniformly transient graphs " October 8, 2016: AMS Sectional Meeting Special Session on "Unimodularity in Randomly Generated Graphs," University of Denver.

" Uniformly transient graphs " August 4, 2016: Conference on "Operator Theory, Analysis and Mathematical Physics," Euler International Mathematical Institute, St. Petersburg, Russia.

" Essential self-adjointness and the L^2 Liouville property " July 19, 2016: Research Seminar on Discrete Spectral Theory, Potsdam University.

" Intrinsic metrics on graphs " March 25, 2016: Graduate Center Mathfest.

" The Feller property for graphs " March 3, 2016: Fordham Analysis Seminar.

" Uniform transience and the (strong) Feller property " July 23, 2015: Conference on "Geometry and Analysis on Graphs," Fudan University, Shanghai, China.

" Aspects of the Feller property on graphs " February 9, 2015: Mini-Workshop on "Discrete p-Laplacians: Spectral Theory and Variational Methods in Mathematics and Computer Science," Mathematisches Forschungsinstitut Oberwolfach.

" The Feller property for graphs " September 30, 2014: Research Seminar, Department of Mathematics and Computer Science, Bronx Community College.

" The Feller property for graphs " June 18, 2014: Seminar on Analysis, Geometry and Stochastics, Friedrich Schiller University of Jena, Germany.

" Spectral properties and intrinsic metrics on infinite graphs " September 26, 2013: Nonlinear Analysis and PDEs Seminar, Graduate Center of the City University of New York.

" Intrinsic metrics on graphs " August 1, 2013: 36th Conference on "Stochastic Processes and their Applications," University of Colorado Boulder.

" Intrinsic metrics on infinite graphs " July 19, 2013: London Mathematical Society -- EPSRC Durham Symposium on "Graph Theory and Interactions".

" Applications of intrinsic metrics to spectral problems on graphs " March 29, 2013: Analysis and Dynamics Seminar of the University of Denver.

" Graphs of unbounded geometry and intrinsic metrics " March 1, 2013: Analysis and Probability Seminar, University of Connecticut.

" Intrinsic metrics on weighted graphs " November 27, 2012: Differential Geometry Seminar, Graduate Center of the City University of New York.

" Intrinsic metrics on weighted graphs " October 23, 2012: Research Seminar, Department of Mathematics and Computer Science, Bronx Community College.

" Uniqueness of self-adjoint extensions of graph Laplacians " August 16, 2012: Seminar on Analysis, Geometry and Stochastics, Friedrich Schiller University of Jena, Germany.

" Heat kernels on graphs: symmetry and stochastic completeness " February 16, 2012: Probability Seminar, Department of Mathematics, University of Colorado Boulder.

" Symmetry, heat kernels, and spectrum of infinite weighted graphs " July 12, 2011: Research Seminar in Analysis, Friedrich Schiller University of Jena, Germany.

" Symmetry, heat kernels, and spectrum of infinite weighted graphs " July 5, 2011: Seminar of the Group of Mathematical Physics, Institute for Interdisciplinary Investigation of the University of Lisbon, Portugal.

" Dirichlet and Neumann Laplacians on infinite graphs " May 6, 2011: Penn State Altoona Mathematics Colloquium.

" Spherically symmetric graphs " July 2, 2010: Research Seminar in Analysis, Friedrich Schiller University of Jena, Germany.

" Spherically symmetric graphs " May 14, 2010: Geometric Analysis Research Seminar, Bielefeld University, Germany.

" Stochastic completeness of graphs " April 2, 2010: Conference on "Classical and Random Dynamics in Mathematical Physics," The University of Texas at Austin.

" Stochastically incomplete manifolds and graphs " March 23, 2010: Differential Geometry Seminar, Graduate Center of the City University of New York.

" Stochastically incomplete graphs " November 6, 2009: Geometry Seminar, Center of Mathematics and Fundamental Applications of the University of Lisbon, Portugal.

" Stochastic incompleteness of the heat kernel on graphs " July 4, 2009: Alp-Workshop, St. Kathrein, Austria.

" Properties of the heat kernel on graphs " June 3, 2009: Research Seminar in Analysis, Friedrich Schiller University of Jena, Germany.

" The heat equation on graphs " March 25, 2009: Seminar of the Group of Mathematical Physics, Interdisciplinary Complex of the University of Lisbon, Portugal.

Professional Honors, Prizes, Fellowships

Simons Visiting Professor (SVP) funded by Simons Foundation and Mathematisches Forschungsinstitut Oberwolfach (MFO): 2021.

Community Service, York College SGA Award: 2016.

Outstanding Leadership, York College SGA Award: 2014-15.

Research Grant for Doctoral Students, Graduate Center, CUNY: 2007.

University Fellowships, Graduate Center, CUNY: 2003-2007.

Graduate Teaching Fellowship, BMCC: 2003-2005.

Science Fellowship, Graduate Center, CUNY,: 2001-2003.

Marie S. Wilcox Scholarship in Science, Indiana University: 2000-2001.

Grants-In-Aid

Simons Foundation, Travel support for mathematicians. 2021-2026: $42,000.00.

National Science Foundation (NSF), Providing Scholarships and Interdisciplinary Cohort Experiences to Increase Retention and Graduation of STEM Undergraduates in Chemistry, Computer Science, Mathematics, and Physics (with Thitima Srivatanakul (PI), Fenio Annansingh-Jamieson (Co-PI), and Leslie Keiler (Co-PI)). 1/15/2021 - 12/31/2025: $649,955.00.

Simons Foundation, Collaboration grant for mathematicians. 2014-2019: $35,000.00.

PSC-CUNY 51 Research Grant, The Neumann Laplacian on graphs and exhaustion. 2020-2021: $3499.45.

PSC-CUNY 50 Research Grant, Graph coverings, amenability and the bottom of the spectrum. 2019-2020: $3,499.52.

National Science Foundation (NSF), International Conference on Analysis and Geometry on Graphs and Manifolds. 2017-2018: $18,000.00.

PSC-CUNY 48 Research Grant, Essential self-adjointness and the l^2-Liouville property. 2017-2018: $3,499.02.

PSC-CUNY 47 Research Grant, Coverings of graphs and the heat kernel. 2016-2017: $3,499.02.

PSC-CUNY 46 Research Grant, Green’s function and uniform transience for infinite graphs. 2015-2016: $3,499.02.

PSC-CUNY 45 Research Grant, Spherical symmetry for infinite graphs. 2014-2015: $3,499.64.

PSC-CUNY 43 Research Grant, Adapted metrics on graphs: essential self-adjointness and the bottom of the spectrum. 2012-2013: $3,499.64.

PSC-CUNY 42 Research Grant, Connections between continuous and discrete structures. 2011-2012: $3,499.64.

FCT - Fundação para a Ciência e a Tecnologia, Eigenvalues of the Laplacian: analytic, geometric and computational aspects (with C. Alves, P. Antunes, D. Borisov, P. Freitas (PR), and I. Salavessa). 2010-2013: 149,432.00€.

FCT - Fundação para a Ciência e a Tecnologia, Postdoctoral grant: SFRH/BPD/45419/2008. 2009-2010: 27,000.00€.

Other Professional Activities and Public Service

Member of the American Mathematical Society: 2001 to 2008, 2011 to present.

"Students Who Code" club mentor, Queens High School for the Sciences at York College: Fall 2015.

Queens High School for the Sciences at York College student mentor: Fall 2015.