Bernard Helffer

7.7k total citations
217 papers, 3.9k citations indexed

About

Bernard Helffer is a scholar working on Mathematical Physics, Computational Theory and Mathematics and Applied Mathematics. According to data from OpenAlex, Bernard Helffer has authored 217 papers receiving a total of 3.9k indexed citations (citations by other indexed papers that have themselves been cited), including 144 papers in Mathematical Physics, 84 papers in Computational Theory and Mathematics and 59 papers in Applied Mathematics. Recurrent topics in Bernard Helffer's work include Spectral Theory in Mathematical Physics (117 papers), Advanced Mathematical Modeling in Engineering (80 papers) and Numerical methods in inverse problems (51 papers). Bernard Helffer is often cited by papers focused on Spectral Theory in Mathematical Physics (117 papers), Advanced Mathematical Modeling in Engineering (80 papers) and Numerical methods in inverse problems (51 papers). Bernard Helffer collaborates with scholars based in France, United States and Austria. Bernard Helffer's co-authors include Johannes Sjöstrand, Didier Robert, Francis Nier, Søren Fournais, Jean Nourrigat, Thomas Hoffmann-Ostenhof, Monique Dauge, D. Robert, Xing‐Bin Pan and A. Martinez and has published in prestigious journals such as Communications in Mathematical Physics, Communications on Pure and Applied Mathematics and Lecture notes in mathematics.

In The Last Decade

Bernard Helffer

202 papers receiving 3.5k citations

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
Bernard Helffer France 33 2.8k 1.3k 1.1k 1.1k 651 217 3.9k
Johannes Sjöstrand France 37 2.9k 1.0× 1.0k 0.8× 1.3k 1.2× 1.3k 1.1× 667 1.0× 132 4.1k
Maciej Zworski United States 33 2.5k 0.9× 668 0.5× 1.4k 1.3× 741 0.7× 678 1.0× 119 3.4k
Raphaël Høegh-Krohn Norway 25 2.0k 0.7× 572 0.4× 1.1k 0.9× 602 0.5× 1.1k 1.7× 70 3.2k
Fritz Gesztesy United States 38 3.2k 1.1× 1.5k 1.1× 2.1k 1.9× 1.2k 1.0× 1.2k 1.8× 219 4.9k
Michael Loss United States 25 1.5k 0.6× 755 0.6× 460 0.4× 1.4k 1.3× 471 0.7× 80 2.7k
Ola Bratteli Norway 24 2.8k 1.0× 450 0.3× 1.3k 1.1× 748 0.7× 1.6k 2.4× 92 4.6k
Pavel Exner Czechia 28 2.3k 0.8× 1.1k 0.9× 1.2k 1.1× 358 0.3× 1.5k 2.3× 230 3.4k
Israel Michael Sigal Canada 29 2.2k 0.8× 416 0.3× 1.4k 1.3× 399 0.4× 1.3k 2.0× 124 3.1k
Eric A. Carlen United States 26 777 0.3× 446 0.3× 473 0.4× 1.1k 1.0× 261 0.4× 105 2.2k
Eugene Trubowitz Switzerland 21 1.4k 0.5× 401 0.3× 1.2k 1.1× 324 0.3× 491 0.8× 83 2.3k

Countries citing papers authored by Bernard Helffer

Since Specialization
Citations

This map shows the geographic impact of Bernard Helffer's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Bernard Helffer with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Bernard Helffer more than expected).

Fields of papers citing papers by Bernard Helffer

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Bernard Helffer. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Bernard Helffer. The network helps show where Bernard Helffer may publish in the future.

Co-authorship network of co-authors of Bernard Helffer

This figure shows the co-authorship network connecting the top 25 collaborators of Bernard Helffer. A scholar is included among the top collaborators of Bernard Helffer based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Bernard Helffer. Bernard Helffer is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
2.
Cornean, Horia D., Bernard Helffer, & Radu Purice. (2024). Matrix Representation of Magnetic Pseudo-Differential Operators via Tight Gabor Frames. Journal of Fourier Analysis and Applications. 30(2). 2 indexed citations
3.
Helffer, Bernard & Ayman Kachmar. (2023). Helical magnetic fields and semi-classical asymptotics of the lowest eigenvalue. Documenta Mathematica. 28(4). 857–901.
4.
Bérard, Pierre, et al.. (2021). Courant-sharp eigenvalues of compact flat surfaces: Klein bottles and cylinders. Proceedings of the American Mathematical Society. 150(1). 439–453. 1 indexed citations
5.
Bérard, Pierre, et al.. (2021). Courant-sharp property for Dirichlet eigenfunctions on the Möbius strip. Portugaliae Mathematica. 78(1). 1–41. 4 indexed citations
6.
Helffer, Bernard & Johannes Sjöstrand. (2021). Improving Semigroup Bounds with Resolvent Estimates. Integral Equations and Operator Theory. 93(3). 7 indexed citations
7.
Helffer, Bernard, et al.. (2019). On the semiclassical analysis of the ground state energy of the Dirichlet Pauli operator III: magnetic fields that change sign. Institutional Research Information System (Università degli Studi di Brescia). 2 indexed citations
8.
Helffer, Bernard & Pierre Bérard. (2018). On Courant's Nodal Domain Property for Linear Combinations of Eigenfunctions. I. Documenta Mathematica. 23. 1561–1585. 4 indexed citations
9.
Bérard, Pierre & Bernard Helffer. (2016). The weak Pleijel theorem with geometric control. Journal of Spectral Theory. 6(4). 717–733. 4 indexed citations
10.
Fournais, Søren, Bernard Helffer, & Mikael Persson. (2011). Superconductivity between $H_{C_2}$ and $H_{C_3}$. Journal of Spectral Theory. 1(3). 273–298. 4 indexed citations
11.
Fournais, Søren & Bernard Helffer. (2010). Bulk superconductivity in Type II superconductors near the second critical field. Journal of the European Mathematical Society. 12(2). 461–470. 4 indexed citations
12.
Ancona, Alano, Bernard Helffer, & Thomas Hoffmann-Ostenhof. (2004). Nodal domain theorems à la Courant. Documenta Mathematica. 9. 283–299. 8 indexed citations
13.
Barbaroux, Jean-Marie, Heinz Siedentop, Volker Bach, & Bernard Helffer. (1998). Stability of matter for the Hartree-Fock functional of the relativistic electron-positron field. Documenta Mathematica. 3. 353–364. 5 indexed citations
14.
Helffer, Bernard, et al.. (1993). An application of semi-classical analysis to the asymptotic study of the supercooling field of a superconducting material. French digital mathematics library (Numdam). 58(2). 189–233. 30 indexed citations
15.
Helffer, Bernard & Johannes Sjöstrand. (1990). On diamagnetism and de Haas-van Alphen effect. French digital mathematics library (Numdam). 52(4). 303–375. 35 indexed citations
16.
Helffer, Bernard. (1987). On a Conjecture of P. Jorgensen and W. Klink. Publications of the Research Institute for Mathematical Sciences. 23(6). 1007–1013.
17.
Helffer, Bernard & Johannes Sjöstrand. (1987). Analyse semi-classique pour l'équation de Harper. French digital mathematics library (Numdam). 40. 1–12. 10 indexed citations
18.
Helffer, Bernard. (1987). Opérateurs de Schrödinger avec champ magnétique. French digital mathematics library (Numdam). 1–14. 1 indexed citations
19.
Helffer, Bernard. (1984). Théorie spectrale pour des opérateurs globalement elliptiques. Astérisque. 86 indexed citations
20.
Helffer, Bernard & Johannes Sjöstrand. (1984). Multiple wells in the semi-classical limit I. Communications in Partial Differential Equations. 9(4). 337–408. 271 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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