James B. Kennedy
I am a mathematician, currently an assistant professor ("professor auxiliar com agregação") at the Department of Mathematics in the Faculty of Sciences of the University of Lisbon, and a member of the research centre Grupo de Física Matemática (Group of Mathematical Physics, GFM), currently as vice-director.
I was previously (in reverse chronological order) a research fellow in Lisbon within in the scope of the program Investigador FCT 2015 of the Fundação para a Ciência e a Tecnologia, Portugal (reference IF/01461/2015) from 2017 to 2020, a postdoc ("wissenschaftlicher Mitarbeiter") at the Institut für Analysis, Dynamik und Modellierung of the University of Stuttgart, Germany, from 2013 to 2017, a Humboldt Fellow at the Institut für Angewandte Analysis of Ulm University, Germany, from 2011 to 2013, and a postdoc at the Grupo de Física Matemática at the University of Lisbon, Portugal, from 2010 to 2011, after completing my PhD at the School of Mathematics and Statistics of the University of Sydney, Australia, in 2010.
Here you can find my profiles on MathSciNet (subscription required), zbMATH Open, Google Scholar and ORCID, as well as my entry in the Mathematics Genealogy Project.
Contact Details
Postal address: | Departamento de Matemática |
| Faculdade de Ciências da Universidade de Lisboa |
| Campo Grande, Edifício C6 |
| P-1749-016 Lisboa, Portugal |
Office: | C6.1.15 |
Tel: | +351 217 500 277 |
Email: | jbkennedy( AT )ciencias.ulisboa.pt |
Recent Courses
Links redirect to the respective moodle pages hosted by the faculty servers, authentication required. All my course and lecture notes, for these and other courses, are freely available for download and personal use (generally under a CC licence) via this link.
Research Interests
- Elliptic and parabolic partial differential equations
- Applications of operator theory to partial differential equations
- Spectral theory of differential equations
- Isoperimetric and similar inequalities for eigenvalues of differential operators
- Variational methods
- Quantum graphs
Publications and Preprints
Those articles for which copyright restrictions do not apply are available for download for personal use in this folder. Preprint versions are usually available on the arXiv and are linked below; for those papers not available on the arXiv a copy of the accepted manuscript is available in the above-mentioned folder. Please contact me if you wish to obtain a copy of (the published version of) any of these articles and do not have access.
- (with J. P. Ribeiro) Cheeger cuts and Robin spectral minimal partitions of metric graphs, to appear in J. Anal. Math., preprint arXiv:2310.02701
- (with M. Ahrami, Z. El Allali and E. M. Harrell II), Optimizing the fundamental eigenvalue gap of quantum graphs, to appear in J. Phys. A: Math. Theor., preprint arXiv:2401.04344
- Geometric spectral theory of quantum graphs, Commun. Math. 32 (2024), 393-439, preprint arXiv:2310.02707
- (with L. N. Baptista and D. Mugnolo) Mean distance on metric graphs, J. Geom. Anal. 34 (2024), 137, MR4719985, preprint arXiv:2312.04952
- (with P. Freitas) On domain monotonicity of Neumann eigenvalues of convex domains, 2023, preprint arXiv:2307.06593
- (with M. Hofmann and A. Serio) Spectral minimal partitions of unbounded metric graphs, J. Spectr. Theory 13 (2023), 593-622, MR4651734, preprint arXiv:2209.03658
- Translation from the German, W. Arendt and K. Urban, Partial Differential Equations: An Introduction to Analytical and Numerical Methods, Graduate Texts in Mathematics 294, Springer, Cham, 2023, MR4628013
- (with G. Berkolaiko, P. Kurasov and D. Mugnolo) Impediments to diffusion in quantum graphs: geometry-based upper bounds on the spectral gap, Proc. Amer. Math. Soc. 151 (2023), 3439-3455, MR4591778, preprint arXiv:2206.10046
- (with M. Düfel, D. Mugnolo, M. Plümer and M. Täufer) Boundary conditions matter: on the spectrum of infinite quantum graphs, 2022, preprint arXiv:2207.04024
- (with S. Bögli and R. Lang) On the eigenvalues of the Robin Laplacian with a complex parameter, Anal. Math. Phys. 12 (2022), 39, MR4376240, preprint arXiv:1908.06041
- (with D. Buoso) The Bilaplacian with Robin boundary conditions, SIAM J. Math. Anal. 54 (2022), 36-78, MR4358025, preprint arXiv:2105.11249
- (with W. Arendt) Disjointness-preserving operators and isospectral Laplacians, J. Spectr. Theory 11 (2021), 1471-1510, MR4349669, preprint arXiv:2002.09207
- (with M. Hofmann, D. Mugnolo and M. Plümer) On Pleijel's nodal domain theorem for quantum graphs, Ann. Henri Poincaré 22 (2021), 3841-3870, MR4325879, preprint arXiv:2012.05808
- (with P. Freitas) Extremal domains and Pólya-type inequalities for the Robin Laplacian on rectangles and unions of rectangles, Int. Math. Res. Not. IMRN (2021), 13730-13782, MR4320795
- (with J. Rohleder) On the hot spots of quantum graphs, Comm. Pure Appl. Anal. 20 (2021), 3029-3063, MR4315494, preprint arXiv:2003.14335
- (with M. Hofmann) Interlacing and Friedlander-type inequalities for spectral minimal partitions of metric graphs, Lett. Math. Phys. 111 (2021), 96, MR4289271, preprint arXiv:2102.07585
- (with M. Hofmann, D. Mugnolo and M. Plümer) Asymptotics and estimates for spectral minimal partitions of metric graphs, Int. Equ. Oper. Theory 93 (2021), 26, MR4260660, preprint arXiv:2007.01412
- (with P. Kurasov, C. Léna and D. Mugnolo) A theory of spectral partitions of metric graphs, Calc. Var. PDE 60 (2021), 61, MR4239815, preprint arXiv:2005.01126
- A family of diameter-based eigenvalue bounds for quantum graphs, pp. 213-239 in F. M. Atay et al, eds., Discrete and continuous models in the theory of networks, Oper. Theory Adv. Appl. 281, Springer, Cham, 2020, MR4181348, preprint arXiv:1807.08185
- (with R. Lang) On the eigenvalues of quantum graph Laplacians with large complex δ couplings, Port. Math. 77 (2020), 133-161, MR4163973, preprint arXiv:2001.10244
- (with G. Berkolaiko, P. Kurasov and D. Mugnolo) Surgery principles for the spectral analysis of quantum graphs, Trans. Amer. Math. Soc. 372 (2019), 5153-5197, MR4009401, preprint arXiv:1807.08183
- (with J. Rohleder) On the hot spots of quantum trees, Conference proceedings of the joint 89th annual meeting of the International Association of Applied Mathematicians and Mechanics (GAMM) and Deutsche Mathematiker-Vereinigung, PAMM 18 (2018), e201800122, preprint arXiv:1808.02274
- A toy Neumann analogue of the nodal line conjecture, Arch. Math. (Basel) 110 (2018), 261-271, MR3761137, preprint arXiv:1706.10037
- (with G. Berkolaiko, P. Kurasov and D. Mugnolo) Edge connectivity and the spectral gap of combinatorial and quantum graphs, J. Phys. A: Math. Theor. 50 (2017), 365201, MR3688110, preprint arXiv:1702.05264
- (with D. Bucur and P. Freitas) The Robin Problem, Chapter 4 in A. Henrot (ed.), Shape optimization and spectral theory, de Gruyter Open, Warsaw-Berlin, 2017, MR3681148
- (with D. Mugnolo) The Cheeger constant of a quantum graph, Conference proceedings of the joint 87th annual meeting of the International Association of Applied Mathematicians and Mechanics (GAMM) and Deutsche Mathematiker-Vereinigung, PAMM 16 (2016), 875-876, preprint arXiv:1604.07453
- (with P. Freitas) Summation formula inequalities for eigenvalues of Schrödinger operators, J. Spectr. Theory 6 (2016), 483-503, MR3551175, preprint arXiv:1605.01925
- (with P. Kurasov, D. Mugnolo and
G. Malenová) On the spectral gap of a quantum graph, Ann. Henri Poincaré 17 (2016), 2439-2473, MR3535868, preprint arXiv:1504.01962
- (with
D. Daners and J. Glück) Eventually and asymptotically positive semigroups on Banach lattices, J. Differential Equations 261 (2016), 2607-2649, MR3507982, preprint arXiv:1511.05294
- (with P. Freitas) Summation formula inequalities for eigenvalues of the perturbed harmonic oscillator, Osaka J. Math. 53 (2016), MR3492805, preprint arXiv:1605.01928
- (with R. Chill and
D. Hauer)
Nonlinear semigroups generated by j-elliptic functionals, J. Math. Pures Appl. (9) 105 (2016), 415-450, MR3465809, preprint
arXiv:1412.4151
- (with
D. Daners and J. Glück) Eventually positive semigroups of linear operators, J. Math. Anal. Appl. 433 (2016), 1561-1593, MR3398779, preprint arXiv:1511.09020
- (with W. Arendt and A.F.M. ter Elst) Analytical aspects of isospectral drums, Oper. Matrices 8 (2014), 255-277, MR3202939, preprint
arXiv:1305.1775
- (with W. Arendt, A.F.M. ter Elst and
M. Sauter) The Dirichlet-to-Neumann operator via hidden compactness, J. Funct. Anal. 266 (2014), 1757-1786, MR3146835, preprint arXiv:1305.0720
- Closed nodal surfaces for simply connected domains in higher dimensions, Indiana Univ. Math. J. 62 (2013), 785-798, MR3164844, preprint arXiv:1009.1502
- (with P.R.S. Antunes and
P. Freitas) Asymptotic behaviour and numerical approximation of optimal eigenvalues of the Robin Laplacian, ESAIM: Control Optim. Calc. Var. 19 (2013), 438-459, MR3049718, preprint arXiv:1204.0648
- The nodal line of the second eigenfunction of the Robin Laplacian in R2 can be closed, J. Differential Equations 251 (2011), 3606-3624, MR2837697, preprint
arXiv:1009.4768
- On the isoperimetric problem for the higher eigenvalues of the Robin and Wentzell Laplacians, Z. Angew. Math. Phys. 61 (2010), 781-792, MR2726626, preprint
arXiv:0910.3966
- (with D. Daners) On the asymptotic behaviour of the eigenvalues of a Robin problem, Differential Integral Equations 23 (2010), 659-669,
MR2654263, preprint
arXiv:0912.0318
- An isoperimetric inequality for the second eigenvalue of the Laplacian with Robin boundary conditions, Proc. Amer. Math. Soc. 139 (2009), 627-633,
MR2448584
- A Faber-Krahn inequality for the Laplacian with generalised Wentzell boundary conditions, J. Evol. Equ. 8 (2008), 557-582, MR2438387
- (with D. Daners) Uniqueness in the Faber-Krahn inequality for Robin problems, SIAM J. Math. Anal. 39 (2007/08), 1191-1207, MR2368899
- PhD thesis: On the isoperimetric problem for the Laplacian with Robin and Wentzell boundary conditions, The University of Sydney, 2010. Summary in Bull. Aust. Math. Soc. 82 (2010), 348-350, MR2685158
All content is the sole responsibility of the author. Please report any errors or broken links to jbkennedy( AT )ciencias.ulisboa.pt.
Page hosted by the Portal de Ciências of the Faculdade de Ciências da Universidade de Lisboa
Back to profile page
Last update: 16/07/2024