Gerhard Opfer

626 total citations
48 papers, 382 citations indexed

About

Gerhard Opfer is a scholar working on Applied Mathematics, Geometry and Topology and Computational Theory and Mathematics. According to data from OpenAlex, Gerhard Opfer has authored 48 papers receiving a total of 382 indexed citations (citations by other indexed papers that have themselves been cited), including 27 papers in Applied Mathematics, 16 papers in Geometry and Topology and 14 papers in Computational Theory and Mathematics. Recurrent topics in Gerhard Opfer's work include Algebraic and Geometric Analysis (17 papers), Matrix Theory and Algorithms (13 papers) and Advanced Topics in Algebra (10 papers). Gerhard Opfer is often cited by papers focused on Algebraic and Geometric Analysis (17 papers), Matrix Theory and Algorithms (13 papers) and Advanced Topics in Algebra (10 papers). Gerhard Opfer collaborates with scholars based in Germany, Czechia and United States. Gerhard Opfer's co-authors include Hans Joachim Oberle, Glenn Schober, Lothar Reichel, Madan L. Puri, Karin Gatermann, Christoph M. Hoffmann, Carl Geiger, Bernd Fischer, M. Hartmann and Walter Hengartner and has published in prestigious journals such as Mathematics of Computation, SIAM Journal on Numerical Analysis and Archive for Rational Mechanics and Analysis.

In The Last Decade

Gerhard Opfer

45 papers receiving 308 citations

Peers — A (Enhanced Table)

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

Name	h						Papers	Cites
Gerhard Opfer Germany	12	172	160	132	100	63	48	382
Zvi Ziegler Israel	10	118 0.7×	170 1.1×	174 1.3×	149 1.5×	56 0.9×	28	466
Plamen Simeonov United States	11	87 0.5×	165 1.0×	73 0.6×	115 1.1×	25 0.4×	44	341
Борис Сергеевич Кашин Russia	13	107 0.6×	206 1.3×	153 1.2×	104 1.0×	34 0.5×	75	463
Jean-Paul Calvi France	11	97 0.6×	207 1.3×	83 0.6×	141 1.4×	93 1.5×	26	336
Jorge Delgado Spain	13	226 1.3×	85 0.5×	151 1.1×	233 2.3×	70 1.1×	60	531
Stanisław Lewanowicz Poland	13	133 0.8×	304 1.9×	121 0.9×	135 1.4×	23 0.4×	44	469
Zhongyun Liu China	10	213 1.2×	83 0.5×	119 0.9×	26 0.3×	39 0.6×	49	337
J. Szabados Hungary	14	93 0.5×	503 3.1×	361 2.7×	138 1.4×	50 0.8×	91	743
Ralph Alexander United States	12	58 0.3×	157 1.0×	115 0.9×	29 0.3×	109 1.7×	29	392
Nir Cohen Israel	13	246 1.4×	117 0.7×	133 1.0×	31 0.3×	97 1.5×	52	553

Countries citing papers authored by Gerhard Opfer

Since Specialization

Citations

This map shows the geographic impact of Gerhard Opfer'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 Gerhard Opfer with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Gerhard Opfer more than expected).

Fields of papers citing papers by Gerhard Opfer

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Gerhard Opfer. 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 Gerhard Opfer. The network helps show where Gerhard Opfer may publish in the future.

Co-authorship network of co-authors of Gerhard Opfer

This figure shows the co-authorship network connecting the top 25 collaborators of Gerhard Opfer. A scholar is included among the top collaborators of Gerhard Opfer 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 Gerhard Opfer. Gerhard Opfer is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

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20 of 20 papers shown

Opfer, Gerhard, et al.. (2015). Matrices Over Nondivision Algebras Without Eigenvalues. Advances in Applied Clifford Algebras. 26(2). 591–612. 3 indexed citations

Opfer, Gerhard. (2009). Polynomials and Vandermonde matrices over the field of quaternions.. 36(6). 9–16. 11 indexed citations

Opfer, Gerhard, et al.. (2008). Linear equations in quaternionic variables. 10 indexed citations

Opfer, Gerhard, et al.. (2005). FAST GIVENS TRANSFORMATION FOR QUATERNION VALUED MATRICES APPLIED TO HESSENBERG REDUCTIONS. 20. 1–26. 2 indexed citations

Hengartner, Walter & Gerhard Opfer. (2004). Shift Generated Haar Spaces on Compact Domains in the Complex Plane. Constructive Approximation. 22(1). 113–132. 1 indexed citations

Hengartner, Walter, et al.. (2004). Shift Generated Haar Spaces on Unbounded, Closed Domains in the Complex Plane. Computational Methods and Function Theory. 3(1). 151–164. 1 indexed citations

Opfer, Gerhard. (2001). Gary D. Knott, Interpolating Cubic Splines. Journal of Approximation Theory. 112(2). 319–321. 1 indexed citations

Oberle, Hans Joachim, et al.. (1999). On the Construction of Optimal Monotone Cubic Spline Interpolations. Journal of Approximation Theory. 96(2). 182–201. 11 indexed citations

Oberle, Hans Joachim & Gerhard Opfer. (1994). Splines with prescribed modified moments. 343–352. 1 indexed citations

10.

Gatermann, Karin, Christoph M. Hoffmann, & Gerhard Opfer. (1992). Explicit Faber Polynomials on Circular Sectors. Mathematics of Computation. 58(197). 241–241. 3 indexed citations

11.

Gatermann, Karin, Christoph M. Hoffmann, & Gerhard Opfer. (1992). Explicit Faber polynomials on circular sectors. Mathematics of Computation. 58(197). 241–253. 12 indexed citations

12.

Reichel, Lothar & Gerhard Opfer. (1991). Chebyshev-Vandermonde Systems. Mathematics of Computation. 57(196). 703–703. 4 indexed citations

13.

Reichel, Lothar & Gerhard Opfer. (1991). Chebyshev-Vandermonde systems. Mathematics of Computation. 57(196). 703–721. 36 indexed citations

14.

Fischer, Bernd, Gerhard Opfer, & Madan L. Puri. (1991). A local algorithm for constructing non-negative cubic splines. Journal of Approximation Theory. 64(1). 1–16. 9 indexed citations

15.

Hartmann, M. & Gerhard Opfer. (1986). Uniform approximation as a numerical tool for constructing conformal maps. Journal of Computational and Applied Mathematics. 14(1-2). 193–206. 2 indexed citations

16.

Opfer, Gerhard & Glenn Schober. (1984). Richardson's iteration for nonsymmetric matrices. Linear Algebra and its Applications. 58. 343–361. 40 indexed citations

17.

Opfer, Gerhard & Madan L. Puri. (1983). Complex Chebyshev polynomials and generalizations with an application to the optimal choice of interpolating knots in complex planar splines. Journal of Approximation Theory. 37(1). 89–101. 1 indexed citations

18.

Opfer, Gerhard & Madan L. Puri. (1981). Complex planar splines. Journal of Approximation Theory. 31(4). 383–402. 14 indexed citations

19.

Geiger, Carl & Gerhard Opfer. (1978). Complex Chebyshev polynomials on circular sectors. Journal of Approximation Theory. 24(2). 93–118. 5 indexed citations

20.

Opfer, Gerhard. (1969). Die Bestimmung des moduls zweifach zusammenh�ngender gebiete mit Hilfe von Differenzenverfahren. Archive for Rational Mechanics and Analysis. 32(4). 281–297. 11 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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