Lance W . Nielsen, PhD
Professor

Contact
College of Arts and Sciences
Mathematics
HLSB - Hixson Lied Science Building
Lance W . Nielsen, PhD
Professor
Teaching Interests
- Feynman's operational calculus
Research Focus
Feynman's operational calculus, complex dimensions and fractal strings.Department
Mathematics
Position
Professor
Books
- Blending Instantaneous and Continuous Phenomena in Feynman’s Operational Calculus with G. W. Johnson, in “Stochastic Analysis and Mathematical Physics (SAMP/ANESTOC 2002) Proceedings of the Mathematical Legacy of R. P. Feynman”, World Scientific, Sept. 2004.
- Oxford University Press
Noncommutativity and Time-Ordering: Feynman’s Operational Calculus and Beyond, with Michel Lapidus and G. W. Johnson, published by Oxford University Press, in print September 2015.
Articles
- Integral Equations and Operator Theory
Lance Nielsen, The abstract approach to Feynman's operational calculus using arbitrary time-ordering measures is developed using two approaches to addressing the combinatorial complexities which arise. An evolution equation is established for the second of the two approaches and examples are considered.
94, Issue 2, Article Number 15 2022 - New York Journal of Mathematics
Nielsen, Lance A distributional approach to Feynman's operational calculus
20, p. 377-398 2014 - New York Journal of Mathematics
A Distributional Approach to Feynman’s Operational Calculus, New York J. of Math. 20 (2014), 1-22.
2014, p. 1-22 2014 - Journal of Doctoral Nursing Practice
Towards a Comprehensive Stability Theory for Feynman’s Operational Calculus: The Time Independent Setting, Acta Appl. Math., 2014, in press. DOI 10.1007/s10440-014-9957-1.
2014 2014 - Journal of Fuzzy Mathematics
Fuzzy Cores in Spatial Models, J. of Fuzzy Mathematics, Vol. 21, No. 4, 2013.
21, 4 2013 - Mathematical Physics, Analysis and Geometry
Nielsen, Lance Weak Convergence and Banach Space-Valued Functions: Improving the Stability Theory of Feynman's Operational Calculi
14, p. 279-294 2011 - Mathematical Physics, Analysis and Geometry
Weak Convergence and Banach Space-Valued Functions: Improving the Stability Theory of Feynman’s Operational Calculi, Math. Phys. Anal. Geom. 14 (2011), 279-294.
14, 2014 2011 - Acta Applicandae Mathematicae
Nielsen, Lance Feynman's Operational Calculi: Disentangling Away from the Origin
110, p. 409-429 2010 - Critical Review
Clark, T. D., Mordeson, J. N., Nielsen, L., Wierman, M. J. Fuzzy geometry: applied to comparative politics
2, p. 1-12 2008 - Mathematical Physics, Analysis and Geometry
Nielsen, L. Weak convergence and vector-valued functions: Improving the stability theory of feynman's operational calculi
10, p. 271-295 2007 - Mathematical Physics, Analysis and Geometry
Jefferies, B., Johnson, G. W., Nielsen, L. Feynman's operational calculi: Spectral theory for noncommuting self-adjoint operators
10, p. 65-80 2007 - Acta Applicandae Mathematicae
Nielsen, L. Stability properties for feynman's operational calculus in the combined continuous/discrete setting
88, p. 47-79 2005 - Rocky Mountain Journal of Mathematics
Nielsen, L. Time dependent stability for Feynman's operational calculus
35, p. 1347-1368 2005 - Journal of the Korean Mathematical Society
Feynman’s Operational Calculi for Time Dependent Noncommuting Operators, with Brian Jefferies and G. W. Johnson, J. Korean Math. Soc. 38 (2001), 193 – 226
38, 2001, p. 193-226 - Conference Proceedings, Canadian Mathematical Society
A Stability Theorem for Feynman’s Operational Calculus, with G. W. Johnson, Conference Proc., Canadian Mathematical Society, 29 (2000), 351 – 365
29, 2000, p. 351-365 - Proceedings of the American Mathematical Society
Effects of Absolute Continuity in Feynman’s Operational Calculus, Proc. Amer. Math. Soc. 131 (2003), 781-791
131, 2003, p. 781-791 - Acta Applicandae Mathematicae
Stability Properties of Feynman’s Operational Calculus for Exponential Functions of Noncommuting Operators, Acta Applicandae Mathematicae 74, 2002, 265 – 292
74, 2002, p. 265-292 - Rocky Mountain Journal of Mathematics
Time Dependent Stability for Feynman’s Operational Calculus, Rocky Mountain Journal of Mathematics 35 no. 4 (2005), 1347 - 1368
4, 2005, p. 1347-1368 - Acta Applicandae Mathematicae
Stability Properties for Feynman’s Operational Calculus in the Combined Continuous/Discrete Setting, Acta Applicandae Mathematicae 88 (2005), 47 – 79.
88, 2005, p. 47-79 - Mathematical Physics, Analysis and Geometry
Feynman’s Operational Calculi: Spectral Theory for Noncommuting Self – Adjoint Operators, with B. Jefferies and G. W. Johnson, Mathematical Physics, Analysis, and Geometry, 10 (2007), 65 - 80
10, 2007, p. 65-80 - Mathematical Physics, Analysis and Geometry
Weak Convergence and Vector-Valued Functions: Improving the Stability Theory of Feynman’s Operational Calculi, Mathematical Physics, Analysis, and Geometry, 10 (2007), 271 - 295.
10, 2007, p. 271-295 - Integration: Mathematical Theory and Applications
An Integral Equation for Feynman’s Operational Calculus, Integration: Mathematical Theory and Applications, Volume 1, Number 1, 2008, pp. 49 - 66.
1, 2008, p. 49-66 - Acta Applicandae Mathematicae
Feynman’s Operational Calculi: Disentangling Away from the Origin, Acta Applicandae Mathematicae ,110 (2010), 409-429.
110, 2010, p. 409-429 - New York Journal of Mathematics
á Feynman’s Operational Calculus : Using Cauchy’s Integral Formula, New York J. of Math. (16) 2010, 1 - 26.
16, 2010, p. 1-26 - Mathematical Physics, Analysis and Geometry
Weak Convergence and Banach Space-Valued Functions: Improving the Stability Theory of Feynman’s Operational Calculi, Math. Phys. Anal. Geom. 14 (2011), 279-294.
14, 2011, p. 279-294 - New York Journal of Mathematics
A Distributional Approach to Feynman’s Operational Calculus, New York J. of Math. 20 (2014), 1-22.
20, 2014, p. 1-22 - Acta Applicandae Mathematicae
Towards a Comprehensive Stability Theory for Feynman’s Operational Calculus: The Time Independent Setting, Acta Appl. Math., 138 (2015), 59-79.
138, 2015, p. 59-79 - Acta Applicandae Mathematicae
Towards a Comprehensive Stability Theory for Feynman’s Operational Calculus: The Time-Dependent Setting, submitted for publication, July 30, 2015.
152 (2017), p. 1-31 - Integral Equations and Operator Theory
Combining Continuous and Discrete Phenomena for Feynman’s Operational Calculus in the Presence of a (C0) Semigroup and Feynman-Kac Formulas with Lebesgue-Stieltjes Measures
Nielsen, L. Integr. Equ. Oper. Theory (2018) 90: 12. https://doi.org/10.1007/s00020-018-2428-8 - New York Journal of Mathematics
"Two Approaches to the Use of Unbounded Operators in Feynman's Operational Calculus"
Editing and Reviews
- Analytic Tools for Feynman Integrals, by Vladimir Smirnov, Springer Tracts in Modern Physics 250, Springer, 2012. (Monograph) 2012
Presentations
- Invited lecture at the South Dakota State University department of mathematics seminar. Title: "Essential Ideas and Properties of Feynman's Operational Calculus." 2018
- Presented the invited talk "Feynman's Operational Calculus: Background and Esential Properties" at the spring 2017 Nebraska-Iowa Functional Analysis Seminar at Creighton University. 2017
- Presented the talk: "Combining Continuous and Discrete Phenomena in Feynman's Operational Calcuus in the Presence of a (C_0) Semigroup: Feynman-Kac Formulas with Lebesgue-Stieltjes Measures" at the Joint Meetings of the AMS in Atlanta, GA. 2017
- Presented the talk "An Evolution Equation for Feynman's Operational Calculus in the Combined Continuous/Discrete Setting" at the Joint Meetings of the AMS in Seattle, WA, Jan. 2016. 2016
- Presented the talk: "An Evolution Equation for Feynmans Operational Calculus in the Combined Continuous/Discrete Setting" at the Joint Mathematics Meetings, Jan. 2016, in Seattle, WA 2016
- Presented the invited talk "Towards a Comprehensive Stability Theory for Feynmans Operational Calculus: The Time Independent Setting" during the special session "AMS Special Session on Advances in Analysis and PDEs" at the Joint Meetings of the American Mathematical Society in Baltimore, Jan. 2014. 2014
- Presented three lectures at the functional integration seminar at the University of Nebraska, Lincoln, fall 2012. 2012
- Presented three lectures at the functional integration seminar at the University of Nebraska, Lincoln, spring 2012. 2012
- Presented the contributed talk "Feynmans Operational Calculus: Using Cauchys Integral Formula" at the Joint Meetings of the AMS, Boston, January 2012. 2012
- Presented the contributed talk "Feynmans Operational Calculus: Using Cauchys Integral Formula" at the Joint Meetings of the AMS, Boston, January 2012. 2012
- Presented three lectures at the functional integration seminar at the University of Nebraska, Lincoln, fall 2011. 2011
- Presented the invited talk "Feynmans Operational Calculus: Background and a Survey of Current Research" at the University of Nebraska, Omaha, April 22, 2011 2011
- Presented two lectures at the functional integration seminar at the University of Nebrask, Lincoln, spring 2011. 2011
- Presented two lectures at the functional integration seminar at the University of Nebraska, Lincoln, fall 2010. 2010
- Presented three lectures at the functional integration seminar at the University of Nebraska, Lincoln, spring 2010. 2010
- Presented "Feynman's Operational Calculus Beyond an Introduction" at the University of California, Riverside, March 2009. 2009
- Presented 4 lectures on current research at the Functional Integration Seminar at UNL, Fall 2008. 2008
- Presented "Weak Convergence and Vector-Valued Functions: Improving the Stability Theory of Feynman's Operational Calculus" at the Joint Meetings of the AMS, Jan. 2008 2008
- Presented 5 lectures at the Functional Integration Seminar at UNL in Fall 2007. 2007
- Presented 6 lectures at the Functional Integration Seminar, Spring 2007. 2007
- Presented 5 lectures on current research at the Functional Integration Seminar at UNL in Spring 2006. 2006
- Presented "An Integral Equation for Feynman's Operational Calculus" at "The Feynman Integral and Related Topics in Mathematics and Physics" at UNL in 2006. 2006
- Presented 5 lectures on current research at the Functional Integration Seminar at UNL, spring 2005. 2005
- Presented "An Integral Equation for Feynman's Operational Calculus" at the Joint Meetings of the AMS, Jan. 2005. 2005
- Presented 8 lectures on current research at the Functional Integration Seminar at UNL in Fall 2004 2004
- Eight lectures on on-going research at the Functional Integration Seminar at UNL in the fall of 2004 2004
- Presented 5 lectures on current research at the Functional Integration Seminar at UNL in Spring 2003. 2003
- Invited Lecture - "A Survey of Feynman's Operational Calculus" at the Nebraska Iowa Functional Analysis Seminar, April 2003. 2003
- Presented "Blending Instantaneous and Continuous Phenomena in Feynman's Operational Calclus" at the Joint Meetings of the AMS, Jan. 2003 2003
- Presented 8 lectures on current research at the Functional Integration Seminar during the Fall of 2002. 2002
- Presented 6 lectures on current research at the Functional Integration Seminar at UNL in the Spring of 2001 2001
- Presented "Effects of Absolute Continuity in Feynman's Operational Calculus" at the Joint Meetings of the AMS, January 2001. 2001
- Presented 6 lectures on current research at the Functional Integration Seminar at UNL during the Fall of 2000. 2000
- Presented "Stability Properties for Feynman's Operational Calculus" at the International Conference on Feynman Integrals and Related Topics. 1999
- Presented the invited lecture "Feynmans Operational Calculi : Background and a Survey of Current Research" at the Nebraska - Iowa Functional Analysis Seminar in Des Moines, IA
- Presented the invited talk "An Integral Equation for Feynmans Operational Calculi" at "The 10th International Conference on Path Integrals" held at Howard University, Washington, D.C.
- Presented the invited talk "Towards a Comprehensive Stability Theory for Feynmans Operational Calculus: The Time Independent Setting" during the special session "AMS Special Session on Advances in Analysis and PDEs" at the Joint Meetings of the American Mathematical Society in Baltimore, Jan. 2014.
- Presented the talk: "Towards a Comprehensive Stability Theory for Feynmans Operational Calculus: The Time Independent and the Time-Dependent Settings" at the Joint Mathematics Meetings, Jan. 2015, in San Antonio.