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- Born April 23, 1954.
 - 1961-1973 student at Subcetate High School, Harghita County.
 - 1974-1978 student at the Faculty of Mathematics, University of Bucharest.
 - 1978-1990 professor of mathematics at the School 131 Bucharest.
 - 1990-2019 teacher at the Faculty of Physics, University of Bucharest.
 - 1995-1996, 1998 PhD student at the National Polytechnic Institute of Grenoble.
 - 1996 Doctorate in Mathematics (University of Bucharest).
 - 1998 Doctorate in Physics (Institut National Polytechnique de Grenoble).
 - 2007-2011 six research internships at Universite Paris 7 Denis Diderot.
 
ORCID iD: https://orcid.org/0000-0003-4518-4950
Articles published in : Physical Review A, Journal of Physics A: Mathematical and Theoretical, Journal of Mathematical Physics, Central European Journal of Physics, Philosophical Magazine, Journal of Geometry and Physics, Electronic Transactions on Numerical Analysis, Ferroelectrics, Zeitschrift für Kristallographie, Letters in Mathematical Physics, Journal of Physics: Condensed Matter, Mathematical Reviews, Zeitschrift für Mathematik (see the section Documente or Web of Science or Research Gate or Scopus or Google Scholar or Academia).
Published books : Elements of Mathematical Analysis (2017), Elements of Linear Algebra (2015), Complements of Mathematics (2012) (see the Documente section).
Communications presented at conferences : Paris (1994), Balatonfured (1995), Paris (1996), Alpe d'Huez (1997), Paris (1998), Stuttgart (1999), Prague (2000), Nijmegen (2000), Paris ( 2002), Lisbon (2003), Bello Horizonte (Brazil) (2003), Leganes (2004), Stockholm (2004), Prague (2004), Ames (Iowa-USA) (2005), Oostende (2005), Toulouse (2005) ), Gothenburg (2005), Varna (2005), Puerto De La Cruz (Tenerife) (2005), Paphos (Cyprus) (2006), New York (2006), Zao (Japan) (2006), Varsac (Serbia) ( 2007), Tel Aviv (2007), Tianjin (China) (2012) (see the Documente section).
Photos: Subcetate-2017 , Subcetate , Domnesti-Sep. 2019 , Predeal-2019
LIST OF MY DOCUMENTS
Recently published articles
- Frame-dependent coherence of a quantum state (Physics Letters A Volume 555, 28 September 2025, 130765)
 - Frame representation of quantum systems with finite-dimensional Hilbert space (Journal of Physics A: Mathematical and Theoretical 57 (2024), 395301)
 - Mixed discrete-variable Gaussian states (Physical Review A 107 (2023), 052215 )
 
An Introduction to Linear Algebra (see the Documente section)
- ELEMENTS OF LINEAR ALGEBRA AND SOME APPLICATIONS (26 pages, version 11 Oct. 2021)
 - ELEMENTS OF LINEAR ALGEBRA (342 pages in Romanian, version 2015)
 - LINEAR ALGEBRA - Solved Exercises 1 (2 pages, version 09 Feb. 2021)
 - LINEAR ALGEBRA - Solved Exercises 2 (2 pages, version 16 Feb. 2022)
 - LINEAR ALGEBRA - Solved Exercises 3 (2 pages, version 5 Feb. 2023)
 - LINEAR ALGEBRA - Solved Exercises 4 (2 pages, version 1 Feb. 2024)
 - LINEAR ALGEBRA - Solved Exercises 5 (2 pages, version 28 Jan. 2025)
 - Differential Equations - Exercises (1 page, version 02 Mar 2023)
 - QUANTUM COMPUTING: PRINCIPLES AND APPLICATIONS
 - An overview on the notion of vector space (video clip on YouTube, 14 Oct. 2020)
 - Basis of a vector space (video clip on YouTube, 16 Oct. 2020)
 - Dimension of a vector space (video clip on YouTube, 18 Oct. 2020)
 - Coordinates of a vector (video clip on YouTube, 19 Oct. 2020)
 - Sum of vector spaces (video clip on YouTube, 20 Oct. 2020)
 - REFERENCES 
- Wilde's book, chapter 3 - The Noiseless Quantum Theory
 - Nielsen & Chuang book, chapters 1,2 - Introduction to Quantum Mechanics
 - Preskill's Lecture Notes - States and Ensembles
 - Preskill's Lecture Notes - Measurement and Evolution
 - Preskill's Lecture Notes - Quantum Entanglement
 - Paris's tutorial on quantum states, measurements, and operations
 - Carlos Navarrete-Benlloch - Introduction to quantum optics
 
 
An Introduction to Complex Analysis (see the Documente section)
- An overview on COMPLEX ANALYSIS (1 page, version 27 Apr. 2020)
 - COMPLEX ANALYSIS - Problems (1 page, version 29 May 2020)
 - COMPLEX ANALYSIS - Solved Problems 1 (2 pages, version 8 Jun 2024)
 - COMPLEX ANALYSIS - Solved Problems 2 (2 pages, version 3 Jun 2025)
 - COMPLEX ANALYSIS - Solved Problems 3 (2 pages, version 4 Jun 2025)
 - Mathematical structures on C (video clip on YouTube, 26 May 2020)
 - Complex functions (video clip on YouTube, 26 May 2020)
 - Complex-differentiable functions (video clip on YouTube, 27 May 2020)
 - Complex integral (video clip on YouTube, 28 May 2020)
 - Residues of a function (video clip on YouTube, 28 May 2020)
 - Theorem of residues (video clip on YouTube, 28 May 2020)
 - Elements of Complex Analysis (63 pages, version 18 Apr. 2020)
 - ELEMENTS OF MATHEMATICAL ANALYSIS (377 pages in Romanian, version 2017)
 
An Introduction to Differential Equations (see the Documente section)
- DIFFERENTIAL EQUATIONS - Theory and Exercises (2 pages, version 12 Mar. 2025)
 - An overview on LINEAR DIFFERENTIAL EQUATIONS (1 page, version 04 Feb. 2020)
 - DIFFERENTIAL EQUATIONS - Exercises (1 page, version 02 Mar 2023)
 - DIFFERENTIAL EQUATIONS - Solved Exercises 1 (2 pages, version 19 Jun 2024)
 - DIFFERENTIAL EQUATIONS - Solved Exercises 2 (2 pages, version 29 Apr 2025)
 - Test filmare cu telefonul (video clip on YouTube, 18 Mar. 2020)
 - Systems of Linear Differential Equations 1 (video clip on YouTube, 22 Mar. 2020)
 - Systems of Linear Differential Equations 2 (video clip on YouTube, 26 Mar. 2020)
 - ELEMENTS OF LINEAR ALGEBRA (342 pages in Romanian, version 2015)
 
An Introduction to Fourier Analysis (see the Documente section)
- An overview on FOURIER ANALYSIS (1 page, version 25 Apr. 2020)
 - FOURIER ANALYSIS - Programs in Mathematica (9 pages, version 07 May 2020)
 - Discrete Fourier Transform 1a (video clip on YouTube, 25Mar. 2020)
 - Discrete Fourier Transform 1b (video clip on YouTube, 25 Mar. 2020)
 - Discrete Fourier Transform 2 (video clip on YouTube, 27 Mar. 2020)
 - Fast Fourier Transform (video clip on YouTube, 31 Mar. 2020)
 - Image Reconstruction 1 (video clip on YouTube, 26 May 2020)
 - ELEMENTS OF MATHEMATICAL ANALYSIS (377 pages in Romanian, version 2017)
 - COMPLEMENTS OF MATHEMATICS (295 pages in Romanian, version 2012)
 - REFERENCES
 
Mathematical Tools for Quantum Mechanics (see the Documente section)
- On a discrete version of the position-momentum commutation relation ( https://arxiv.org/pdf/2509.22753) - 13 pages, version 7 Oct. 2025
 - On the CONTINUOUS-DISCRETE quantum system correspondence (3 pages, 22 Feb. 2022)
 - Discrete-variable Gaussian states and the canonical commutation relation - 5 pages, version 6 May 2025
 - Frame-dependent coherence of a quantum state ( https://arxiv.org/pdf/2502.04178) - 17 pages, version 14 Apr. 2025
 - Frame representation of quantum systems with finite-dimensional Hilbert space (https://iopscience.iop.org/article/10.1088/1751-8121/ad74bd)
 - Frame representations of qudit quantum mechanics ( https://arxiv.org/pdf/2305.19287.pdf) - 19 pages, version 28 May 2024
 - Quantum states defined by using the finite frame quantization (14 pages, version 15 July 2022)
 - Mixed discrete-variable Gaussian states (Phys. Rev. A 107 (2023), 052215 )
 - On a discrete version of the ambiguity function (2 pages, 18 Apr. 2022)
 - Explicit expression of Wigner function of a Gaussian function of discrete variable (1 page, 18 Jan. 2022)
 - ON A DISCRETE VERSION OF THE WEYL-WIGNER DESCRIPTION (10 pages, version 20 Feb. 2022)
 - MATHEMATICAL DESCRIPTION OF QUANTUM SYSTEMS (19 pages, version 28 Jul. 2021)
 - On the mathematical description of the GAUSSIAN STATES (in preparation, 13 Oct. 2020)
 - An overview on CONTINUOUS versus DISCRETE WIGNER FUNCTION (1 page, version 23 Jan. 2020)
 - QUASIPROBABILITY REPRESENTATIONS OF FINITE QUANTUM SYSTEMS (1 page, 19 Jan. 2020)
 - An overview on POISSON SUMMATION FORMULA and ZAK TRANSFORM (1 page, 06 Mar. 2020)
 - An overview on FRAMES AND TIGHT FRAMES (1 page, version 15 Jun. 2020)
 - Overview on UNITARY IRREDUCIBLE REPRESENTATIONS OF SU(2) (1 page, version 01 Dec. 2019)
 - An overview on GAUSSIAN FUNCTIONS OF DISCRETE VARIABLE (1 page, version 17 Jan. 2020)
 - Gaussian functions of two discrete variables (7 pages, version 03 Dec. 2019)
 - Continuous versus Discrete Quantum Systems (22 pages, version 01 Dec. 2019)
 - On the mathematical bases of qutrit quantum mechanics (8 pages, version 01 Dec. 2019)
 - REFERENCES
 
My main articles and communications (see the Documente section)
- N. Cotfas - Main published articles (article influence + times cited)
 - N. Cotfas - Communications presented at conferences
 
Unpublished papers
- On the Gaussian functions of two discrete variables
 - Linear representations of SU(2) described by using Kravchuk polynomials
 - Gaussian type functions defined on a finite set and finite oscillators
 
 
                                                    
                                                         
                        