Prof. Dr. Radu **Precup**, corresponding member of the Romanian Academy

Version of December 21, 2021.

### Current position:

- Corresponding member of the Romanian Academy
- Senior researcher at
*“Tiberiu Popoviciu” Institute of Numerical Analysis* - Institute of Advanced Studies in Science and Technology (STAR-UBB), “Babeş-Bolyai” University

### Fields of interest:

- Nonlinear analysis
- Ordinary differential equations
- Partial differential equations
- Mathematical modeling

### Date and place of birth

- 1955, Pesac (Timiş), Romania

### Education

- 1975-1980, Faculty of Mathematics, Babeş-Bolyai University, Cluj-Napoca
- 1985, Ph.D. Babeş-Bolyai University, Cluj-Napoca
- 1990-1991 (9 months), Postdoctoral stage, Bourse du Gouvernement Français (BGF), University of Paris VI

### Fields of interest:

- Nonlinear analysis,
- Ordinary differential equations,
- Partial differential equations,
- Mathematical modeling

### Academic positions

- 1987-1990, Assistant, Babeş-Bolyai University
- 1990-1994, Lecturer, Babeş-Bolyai University
- 1994-1998, Associate Professor, Babeş-Bolyai University
- 1998-2021, Professor, Babeş-Bolyai University
- 2021-prezent, CSI, Institute of Advanced Studies in Science and Technology, Babeş-Bolyai University, Cluj-Napoca & CSI, Tiberiu Popoviciu Institute of Numerical Analysis, Romanian Academy, Cluj-Napoca
- Visiting professor for short periods: University of Metz (2002, 2005, 2014, 2016, 2018), University of Perugia (2014, 2016, 2019), University of Torun (2013), University of Sfax (2013), University of Ruse (2015).

## Editorial activity

- Studia Universitatis Babeş-Bolyai Mathematica (Cluj), Editor-in-Chief;
- Fixed Point Theory (Cluj), Deputy Editor-in-Chief;
- Fixed Point Theory and Algorithms for Sciences and Engineering (Springer), Section Editor;
- Carpathian Journal of Mathematics (Baia Mare), Member of the Editorial Board;
- Mathematics in Engineering, Science and Aerospace (USA), Member of the Board;
- Transylvanian Journal of Mathematics and Mechanics (Romania), Member of the Board;
- Discussiones Mathematicae Differential Inclusions, Control and Optimization (Poland), Member of the Editorial Board.;
- Journal of Inequalities and Special Functions (Poland), Member of the Editorial Board.;
- Mathematica (Romanian Academy), Member of the Editorial Board.;
- Proceedings of the Romanian Academy- Series A, Member of the Editorial Board.

### Conferences organized

- International Conference on Nonlinear Operators, Differential Equations and Applications ICNODEA-Cluj, 2001, 2004, 2007, 2011 and 2015.
- Mini-symposium “Analyse non-linéaire”, 8ième Colloque Franco-Roumain de Mathématiques Appliquées, Chambéry (France), 28 août-1er septembre 2006.
- Workshop (Babeş-Bolyai University – University Paris Sud), Méthodes variationnelles en micromagnétisme, Cluj-Napoca, 2008.
- Special session SS7: Methods of Nonlinear Analysis for Partial Differential Equations, ICNPAA Congress: Mathematical Problems in Engineering, Aerospace and Sciences, Sao Jose dos Campos, Brazilia, 2010.
- Workshop on Nonlinear Analysis on the Occasion of the 65th Birthday of Patrizia Pucci, Cluj-Napoca, May 25-27, 2017.

### Awards

- Prizes of Babeş-Bolyai University: 2001 (for book); 2002, 2009, 2010, 2016 (research);
- Prizes of the Faculty of Mathematics and Computer Science, Cluj-Napoca: 2012 (didactic); 2015 (research)
- Crystal Prize “The Best Paper”-University of Ruse 2015.

### Administrative positions

- Chairman of Chair of Differential Equations of Babeş-Bolyai University of Cluj (2003-2008)
- Director Department of Applied Mathematics of Babeş-Bolyai University of Cluj (2003-2008)
- Director Department of Mathematics of Babeş-Bolyai University of Cluj (2008-2012)
- Director Doctoral School of Mathematics and Computer Science of Babeş-Bolyai University of Cluj (2012-2015)
- Member of Mathematics Committee of CNATDCU (2006-2012)
- Member of the Senate of Babeş-Bolyai University of Cluj (2012-2016)
- Member of the Scientific Council of Babeş-Bolyai University (2017-2020)

### Summary of scientific activity

- Seven books
- More than 180 papers in journals and volumes.
- Citations: 2151 (Google Scholar).
- h-index: 21, i10-index 62 (Google Scholar);
- h-index 14 (Scopus);
- h-index 14 (Web of Science).

**Books:**

- Ordinary Differential Equations, De Gruyter, Berlin, 2018, 234 pp.
- Methods in Nonlinear Integral Equations, Kluwer Academic Publishers, Dordrecht-Boston-London, 2002, 232 pp; Softcover reprint of the original 1st ed. 2002, Springer Netherlands, 2013.
- Linear and Semilinear Partial Differential Equations, De Gruyter, Berlin-Boston, 2013, 294 pp.
- Differential Equations (Romanian), Risoprint, Cluj, 2011, 189 pp.
- Lectures on Partial Differential Equations (Romanian), Cluj University Press, Cluj, 2004, 286
- Theorems of Leray-Schauder Type and Applications (with D. O’Regan), Gordon and Breach Science Publisher, Amsterdam, 2001, 216 pp.
- Partial Differential Equations (Romanian), Transilvania Press, Cluj, 1997, 216 pp.

**Papers:**

- Fixed point-critical point hybrid theorems and application to systems with partial variational structure (with I. Benedetti, T. Cardinali), J. Fixed Point Theory Appl. 23 (2021), 63, 1-19
- Componentwise localization of critical points for functionals defined on product spaces, Topological Methods in Nonlinear Analysis 58 (2021), No. 1, 51-77.
- Analysis of the effectiveness of the treatment of solid tumors in two cases of drug administration (with L.G. Parajdi, M.-A. Serban, I.S. Haplea), Mathematical Biosciences and Engineering 18 (2021), Issue 2, 1845-1863.
- Stationary solutions of Fokker-Planck equations with nonlinear reaction terms in bounded domains (with P. Rubbioni), Potential Analysis, 2021, https://doi.org/10.1007/s11118-021-09911-6.
- Krasnoselskii type theorems in product Banach spaces and applications to systems of nonlinear transport equations and mixed fractional differential equations (with S.H. Amor, A. Traiki), Fixed Point Theory, to appear.
- On the controllability of a system modeling cell dynamics related to leukemia (with Haplea, I.S.; Parajdi, L.G.), Symmetry 2021, 13, 1867. https://doi.org/10.3390/sym13101867
- Positive solutions for second-order differential equations of Kirchhoff type on the half-line (with H. Boulaiki, T. Moussaoui), Carpathian J. Math. 37 (2021), No. 2., 325-338.
- A unified variational approach to discontinuous differential equations (with J. Rodriguez-Lopez), Mediterr. J. Math. 18 (2021), 62, 1-14.
- Implicit elliptic equations via Krasnoselskii-Schaefer type theorems, Electron. J. Qual. Theor. Diff. Eqns. 2020, No. 8 7, 1-9.
- A vector version of the fixed point theorem of cone compression and expansion for a sum of two operators (with L. Benzenati, K. Mebarki), Nonlinear Studies 27 (2020), no. 3, 563-575.
- Krasnosel’skii type compression-expansion fixed point theorem for set contractions and star convex sets (with C. Lois-Prados, R. Rodríguez-López), J. Fixed Point Theory Appl. 22 (2020), 63.
- Theoretical basis of optimal therapy for individual patients in chronic myeloid leukemia: A mathematical approach (with L. G. Parajdi, D. Dima, V. Moisoiu, C. Tomuleasa), Journal of Interdisciplinary Mathematics 23:3 (2020), 669-690.
- Fixed point index theory for decomposable multivalued maps and applications to φ-Laplacian problems (with J. Rodriguez-Lopez), Nonlinear Anal. 199 (2020) 111958, 16 p.
- Harnack type inequalities and multiple solutions in cones of nonlinear problems (with D.R. Herlea, D. O’Regan), Z. Anal. Anwend. 39 (2020), 151-170.
- Integrodifferential evolution systems with nonlocal initial conditions (with S. Koumla), Studia Univ. Babes-Bolyai Math. 65 (2020), 93-108.
- A mathematical model of the transition from the normal hematopoiesis to the chronic and acceleration-acute stages in myeloid leukemia (with LG Parajdi, EA Bonci, C. Tomuleasa), Mathematics 2020, 8, 376, 1-18.
- Solutions with a prescribed interval of positivity for differential systems with nonlocal conditions (with V. Ilea, A. Novac, D. Otrocol), Applied Mathematics and Computation 375 (2020) 125092.
- On the approximation of fixed points for non-self mappings on metric spaces (with A. Petrusel, M-A. Serban), Discrete and Continuous Dynamical Systems – B, 2020, 25(2): 733-747.
- Positive periodic solutions for Lotka-Volterra systems with a general attack rate (with C. Lois Prados), Nonlinear Anal. Real World Appl. 52 (2020), pp 17.
- Localization and multiplicity in the homogenization of nonlinear problems (with R. Bunoiu) , Adv. Nonlinear Anal. 9 (2020), Nr. 1, 292-304.
- Energy-based localization and multiplicity of radially symmetric states for the stationary p-Laplace diffusion (with P. Pucci, C. Varga), Complex Variables and Elliptic Equations 65 (2020):7, 1198-1209.
- Assessment of measurable residual disease in chronic myeloid leukemia. BCR-ABL1 IS in the avant-garde of molecular hematology (with V. Moisoiu, P. Teodorescu, L. Parajdi, S.
- Positive solutions for discontinuous systems via a multivalued vector version of Krasnosel’skii’s fixed point theorem in cones (with R. López Pouso, J. Rodríguez-López), Mathematics 7 (5) (2019), Article 451, pp 15.
- A four-point boundary value problem with singular phi-Laplacian (with A. Chinni, B. Di Bella, P. Jebelean) , J. Fixed Point Theory Appl. (2019) 21:66, pp 16.
- Existence results for some neutral functional integrodifferential equations with bounded delay (with S. Koumla, A. Sene), Turk. J. Math. 43 (2019), no. 4, 1809-1822.
- Positive solutions for φ-Laplace equations with discontinuous state-dependent forcing terms (with J. Rodriguez-Lopez), Nonlinear Analysis: Modelling and Control 24 (2019), No. 3, 447-461.
- Symmetric positive solutions to a singular phi-Laplace equation (cu P. Jebelean), J. London Math. Soc. 99 (2019), 495-515.
- Multiplicity results for operator systems via fixed point index (cu J. Rodriguez-Lopez), Results Math. 74 (2019), Article 25.
- Positive solutions for discontinuous problems with applications to φ-Laplacian equations (cu J. Rodriguez-Lopez), J. Fixed Point Theor. Appl. 20 (2018), Article 156, 17 p.
- Hybrid delay evolution systems with nonlinear constraints (cu O.-M. Bolojan), Dynamic Systems and Applications, 27, No. 4 (2018), 773-790.
- Multiple positive solutions to a (2m)th-order boundary value problem (cu H. Boulaiki, T. Moussaoui), Carpathian J. Math. 34 (2018), 167-182.
- A critical point theorem in bounded convex sets and localization of Nash-type equilibria of nonvariational systems, J. Math. Anal. Appl. 463 (2018), 412-431.
- Analysis of a planar differential system arising from hematology (cu L.G. Parajdi), Stud. Univ. Babeş-Bolyai Math. 63 (2018), 235-244.
- Theory and computation for multiple positive solutions of non-local problems at resonance (cu A. Novac), Journal of Applied Analysis and Computation 8 (2018), 486-497.
- Multiple positive standing wave solutions for Schrödinger equations with oscillating state-dependent potentials (cu R. Bunoiu, C. Varga), Comm. Pure Appl. Anal. 16 (2017), 953-972.
- A three critical point result in a bounded domain of a Banach space and applications (with P. Pucci, C. Varga), Differential Integral Equations 30 (2017), no. 7-8, 555-568.
- Localization of positive critical points in Banach spaces and applications (with C. Varga), Topol. Methods Nonlinear Anal. 49 (2017), 817-833.
- Two abstract approaches in vectorial fixed point theory (with T. Cardinali, P. Rubbioni), Quaestiones Mathematicae 41 (2018), no. 2, 173-188.
- Heterogeneous vectorial fixed point theorems (with T. Cardinali, P. Rubbioni), Mediterr. J. Math. (2017) 14: 83, pp. 12.
- Multiple positive solutions for a second-order boundary value problem on the half-line (cu H. Boulaiki, T. Moussaoui), J. Nonlinear Funct. Anal. 2017 (2017), Article ID 17, 1-25.
- Variational properties of the solutions of singular second-order differential equations and systems (with A. Budescu), J. Fixed Point Theor. Appl. 18 (2016), 505-518.
- Semilinear evolution systems with nonlinear constraints (with O. Bolojan), Fixed Point Theory 17 (2016), 275-288.
- Multiple positive solutions to a fourth order boundary value problem (with A. Cabada, L. Saavedra, S. Tersian), Electron. J. Differential Equations 2016 (2016), No. 254, 1-18.
- A Schechter type critical point result in annular conical domains of a Banach space and applications (with H. Lisei, C. Varga), Discrete Contin. Dyn. Syst. 36 (2016), 3775 – 3789.
- Fixed point theorems under combined topological and variational conditions (with A. Budescu), Results. Math. 70 (2016), Issue 3, 487-497.
- Nash-type equilibria for systems of Szulkin functionals, Set-Valued and VariationalAnalysis 24 (2016), 471-482.
- Variational properties of the solutions of semilinear equations under nonresonance conditions (with A. Budescu), J. Nonlinear Convex Anal. 17 (2016), 1517-1530.
- Abstract method of upper and lower solutions and application to singular boundary value problems, Studia Univ. Babes-Bolyai Math. 61 (2016), 443-451.
- Existence, localization and multiplicity of positive solutions to φ-Laplace equations and systems (with D. Herlea), Taiwanese J. Math. 20 (2016), 77-89.
- Vectorial approach to coupled nonlinear Schrödinger systems under nonlocal Cauchy conditions (with R. Bunoiu), Appl. Anal. 95 (2016), 731-747.
- A topological approach to the existence and multiplicity of positive solutions of (p,q)-Laplacian systems (with G. Infante, M. Maciejewski), Dyn. Partial Differ. Equ. 12 (2015), no.3, 193-215.
- Existence results for systems with nonlinear coupled nonlocal initial conditions (with O. Bolojan-Nica, G. Infante), Math. Bohem. 140 (2015), no. 4, 371-384.
- A unified existence theory for evolution equations and systems under nonlocal conditions (with T. Cardinali and P. Rubbioni), J. Math.Anal.Appl. 432 (2015), 1039-1057.
- Variational properties of the solutions for second-order differential equations and systems on semi-line (with A. Novac), Numer. Funct. Anal. Optim. 36 (2015), 930-941.
- Some fixed point theorems in terms of two measures of noncompactness (with I.A. Rus), Mathematica 56 (79) (2014), no 2, 158-165.
- Implicit first order differential systems with nonlocal conditions (with O. Bolojan), Electron. J. Qual. Theory Differ. Equ. 2014, no. 69, 1-13.
- On the continuation method and the nonlinear alternative for Caristi-type non-self-mappings, J. Fixed Point Theory Appl. 16 (2014), 3-10.
- Multiple periodic solutions with prescribed minimal period to second-order Hamiltonian systems, Dyn. Syst. 29 (2014), no. 3, 424-438.
- Perov type results in gauge spaces and applications to integral systems on semi-axis (with A. Novac), Math. Slovaca 64 (2014), 961-972.
- Nash-type equilibria and periodic solutions to nonvariational systems, Adv. Nonlinear Anal., 3 (2014), no. 4, 197-207.
- Existence results for systems with coupled nonlocal conditions (with O. Bolojan-Nica, G. Infante), Nonlinear Anal. 94 (2014), 231-242.
- Critical point localization theorems via Ekeland’s variational principle, Dynamic Systems and Applications 22 (2013), 355-370.
- On a bounded critical point theorem of Schechter, Stud. Univ. Babeş-Bolyai Math. 58 (2013), No. 1, 87-95.
- Asymptotic stability for a model of cell dynamics after allogeneic bone marrow transplantation (with M-A. Serban and D. Trif), Nonlinear Dynamics and Systems Theory 13 (1) (2013), 79-92.
- Abstract weak Harnack inequality, multiple fixed points and p-Laplace equations, J. Fixed Point Theory Appl. 12 (2012), 193-206.
- Moser-Harnack inequality, Krasnoselskii type fixed point theorems in cones and elliptic problems, Topol. Methods Nonlinear Anal. 40 (2012), 301-313.
- Multiple positive solutions of non-local initial value problems for first order differential systems (with D. Trif), Nonlinear Anal. 75 (2012), 5961-5970.
- Critical point theorems in cones and multiple positive solutions of elliptic problems, Nonlinear Anal. 75 (2012), 834-851.
- Mathematical understanding of the autologous stem cell transplantation, Ann. Tiberiu Popoviciu Semin. Funct. Equ. Approx. Convexity 10 (2012), 155-167.
- A planning algorithm for correction therapies after allogeneic stem cell transplantation (with M-A Serban, D Trif, A Cucuianu), J. Math. Model. Algor. 11 (2012), No. 3, 309-323.
- Mathematical modeling of cell dynamics after allogeneic bone marrow transplantation (in cooperation), Int. J. Biomath. 5 (2012), No. 2, 1250026 (18 pages) doi: 10.1142/S1793524511001684.
- On the nonlocal initial value problem for first order differential systems (with O. Nica), Stud. Univ. Babeş-Bolyai Math. 56 (2011), No. 3, 113-125.
- Positive solutions of functional-differential systems via the vector version of Krasnoselskii’s fixed point theorem in cones (with S. Budisan), Carpathian J. Math. 27 (2011), 165-172.
- Nonlinear Schrodinger equations via fixed point principles (with M. Manole), Dyn. Contin. Discrete Impuls. Syst. Ser. A Math. Anal. 18 (2011), 705-718.
- Poincare inequalities in reflexive cones (with P. Jebelean), Appl. Math. Letters 24 (2011), 359-363.
- Two positive nontrivial solutions for a class of semilinear elliptic variational systems, J. Math. Anal. Appl. 373 (2011), 138-146.
- Existence results for systems of nonlinear evolution inclusions (with A. Viorel), Fixed Point Theory 11 (2010), 337-346.
- Two positive solutions of some singular boundary value problems, Anal. Appl. 8 (2010), 305-314.
- A mathematical approach to cell dynamics before and after allogeneic bone marrow transplantation (with D. Trif, M-A Serban, A. Cucuianu), Ann. Tiberiu Popoviciu Semin. Funct. Equ. Approx. Convexity 8 (2010), 167-175.
- A hypothetical-mathematical model of acute myeloid leukemia pathogenesis (with A. Cucuianu), Comput. Math. Methods Med. 11 (2010), 49-65.
- Solvability of p,q-Laplacian systems with potential boundary conditions (with P. Jebelean), Appl. Anal. 89 (2010), 221-228.
- Mathematical models of the leukemic hematopoiesis (with A. Cucuianu), Ann. Tiberiu Popoviciu Semin. Funct. Equ. Approx. Convexity 7 (2009), 169-181.
- Mathematical models of the leukemic hematopoiesis (with A. Cucuianu), Ann. Tiberiu Popoviciu Semin. Funct. Equ. Approx. Convexity 7 (2009), 169-181.
- Fourth-order p-Laplacian nonlinear systems via the vector version of Krasnoselskii’s fixed point theorem (with S. Djebali, T. Moussaoui), Mediterr. J. Math. 6 (2009), no. 4, 449-463.
- Existence of solutions for second-order differential equations and systems on infinite intervals (with T. Moussaoui), Electron. J. Diff. Eqns. 2009 (2009), No. 94, 1-13.
- Data dependence of fixed points for non-self generalized contractions (with A. Chis, I.A. Rus), Fixed Point Theory 10 (2009), No.1, 73-87.
- Existence, localization and multiplicity results for positive radial solutions of semilinear elliptic systems, J. Math. Anal. Appl. 352 (2009), 48-56.
- The role of matrices that are convergent to zero in the study of semilinear operator systems, Math. Comp. Modelling 49 (2009), 703-708.
- Existence results for semilinear elliptic boundary value problems via topological methods (with T. Moussaoui), Appl. Math. Letters 22 (2009), 126-129.
- Nonresonance theory for semilinear operator equations under regularity conditions (with D. Muzsi), Annals Tiberiu Popoviciu Seminar 6 (2008), 75-89.
- Radial solutions for some classes of elliptic boundary value problems (with T. Moussaoui), Studia Univ. Babes-Bolyai Math. 53 (2008), no.1, 35-42.
- Nonresonance and existence for systems of nonlinear operator equations (with D. Muzsi), Appl. Anal. 87 (2008), no. 9, 1005-1018.
- Existence results for systems of nonlinear evolution equations (with A. Viorel), Int. J. Pure Appl. Math. 47 (2008), no. 2, 199-206.
- (with T. Moussaoui) Positive solutions for elliptic boundary value problems with a Harnack-like property, Cubo 10 (2008), no. 4, 109-117.
- A compression type mountain pass theorem in conical shells, J. Math. Anal. Appl. 338 (2008), 1116-1130.
- Domain invariance theorems for contractive type maps, (with R.P. Agarwal, D. O’Regan), Dynamic Systems Appl. 16 (3) (2007), 579-586.
- Nonuniform nonresonance for nonlinear boundary value problems with y′dependence, (with R.P. Agarwal, D. O’Regan), Dynamic Systems Appl. 16 (3) (2007), 587-594.
- Homotopy method for positive solutions of p-Laplace inclusions, (with J-F. Couchouron), Topological Methods Nonlinear Anal. 30 (2007), no. 1, 157-169.
- Semilinear evolution equations with nonlocal initial conditions, (with A. Boucherif), Dynamic Systems Appl. 16 (2007), 507-516.
- A vector version of Krasnoselskii’s fixed point theorem in cones and positive periodic solutions of nonlinear systems, J. Fixed Point Theory Appl. (Birkhäuser) 2 (2007), No. 1, 141-151.
- Fixed point theory for admissible pairs and maps in Frechet spaces via degree theory, (with R. Ma, D. O’Regan), Fixed Point Theory 8 (2007), No. 2, 273-283
- Positive solutions of nonlinear systems with p-Laplacian on finite and semi-infinite intervals, (with D. O’Regan), Positivity 11 (2007), no. 3, 537-548.
- Positive solutions of nonlinear systems via the vector version of Krasnoselskii’s fixed point theorem in cones, Annals of the Tiberiu Popoviciu Seminar 5 (2007),129-138.
- The nonlinear heat equation via fixed point principles, Annals of the Tiberiu Popoviciu Seminar 4 (2006).111-127.
- Positive solutions of nonlinear singular integral equations in ordered Banach spaces, (with Yansheng Liu), Nonlinear Funct. Anal. Appl. 11 (2006), No. 3, 447-457. MR2305500, Zbl pre05145463.
- Aronszajn type theorems for integral equations on unbounded domains via maximal solutions, (with D. O’Regan), Fixed Point Theory 4 (2006), no. 2. MR2284602, Zbl pre05142550.
- Note on the abstract generalized quasilinearization method, (with A. Buica), Rev. Anal. Numer. Theor. Approx. 35 (2006), no. 1, 11-15. MR2290474.
- Construction of upper and lower solutions with applications to singular boundary value problems, (with R.P. Agarwal, D. O’Regan), J. Comput. Anal. Appl. 7 (2005), 205-221. MR2223477, Zbl 1085.34016.
- Existence and localization results for semi-linear problems, Annals Univ. Craiova, Math. Comp. Sci. Ser. 32 (2005), 59-66. MR2215896.
- Compression-expansion fixed point theorems in two norms, Annals of the Tiberiu Popoviciu Seminar 3 (2005), 157-163.
- Boundary value problems arising in the percolation of water from a cylindrical reservoir into the surrounding soil, (with R.P. Agarwal, D. O’Regan), Nonlinear Analysis: Real World Applications 6 (2005), 123-131. MR 2104546.
- Compression-expansion fixed point theorem in two norms and applications, (with D. O’Regan), J. Math. Anal. Appl. 309 (2005), 383-391. MR2154122, Zbl 1078.47017.
- Existence theory for nonlinear operator equations of Hammerstein type in Banach spaces, (with D. O’Regan), Dynamic Systems Appl. 14 (2005), 121-134. MR2128316, Zbl 1086.47034.
- Positive solutions of evolution operator equations, Austral. J. Math. Anal. Appl. 2 (2005), Issue 1, 1-10. MR2133376, Zbl 1078.47059.
- Nonnegative solutions of nonlinear integral equations in ordered Banach spaces, (with A. Horvat-Marc), Fixed Point Theory 5 (2004), 65-70. MR 2108895.
- A note on the solvability of the nonlinear wave equation, Rev. Anal. Numér. Théor. Approx. 33 (2004), no. 2, 237-241. MR2192473, Zbl pre05003794.
- Continuation theory for general contractions in gauge spaces, (with A. Chis), Fixed Point Theory and Applications 2004:3 (2004), 173-185. MR 2096949
- Anti-periodic solutions for second order differential inclusions, (with J-F Couchouron), Electron. J. Differential Equations 2004 (2004), 1-17. MR 93a:58028, Zbl 745.54018.
- Existence and localization results for the nonlinear wave equation, Fixed Point Theory 5 (2004), 309-321. MR2117341, Zbl 1107.35086.
- Fixed point theory and generalized Leray-Schauder alternatives for approximable maps in topological vector spaces, (with R. Agarwal, D. O’Regan), Topol. Methods Nonlinear Anal. 22, no. 1 (2003), 193-202. MR 2037275, Zbl pre02096725.
- On nonlocal initial value problem for first order differential equations, (with A. Boucherif), Fixed Point Theory 4 (2003), no. 2, 205-212, MR 2031390, Zbl 105034001.
- The perturbed Klein-Gordon equation, Annals of the Tiberiu Popoviciu Seminar 1 (2003), 141-152.
- Continuation theory for contractions on spaces with two vector-valued metrics, (with D. O’Regan), Appl. Anal. 82 (2003), 131-144. MR 1966853, Zbl 1034.54017.
- A nonlinear periodic averanging principle, (with J-F Couchouron, M. Kamenski), Nonlinear Anal. 54 (2003), 1439-1467. MR 1997229, Zbl 1034.34074.
- Location of nonnegative solutions for differential equations on finite and semi-infinite intervals, (with R.P. Agarwal, M. Meehan, D. O’Regan), Dynamic Systems Appl. 12 (2003), 323-332. MR 2020470, Zbl pre02061133.
- Fixed point theorems for decomposable multi-valued maps and applications, Zeit. Anal. Anwendungen 22 (2003), 843-861. MR2036933
- Some existence results for differential equations with both retarded and advanced arguments, Mathematica (Cluj) 44 (2002). no. 1, 25-31. MR 2057010.
- Fixed point theorems for acyclic multivalued maps and inclusions of Hammerstein type, Seminar on Fixed Point Theory Cluj-Napoca 3 (2002), 327-334. MR 1929778, Zbl 1043.47037.
- Abstract generalized quasiliniarization method for coincidences, (with A. Buica), Nonlinear Stud. 9 (2002), 371-387. MR 1940557, Zbl 1020.65031.
- An inequality which arises in the absence of mountain pass geometry, J. Inequal. Pure Appl. Math. 3 (2002), no.3, 1-10. MR 1917791, Zbl 1010.26013.
- Integrable solutions of Hammerstein integral inclusions in Banach spaces, (with D. O’Regan), Dynamics Cont. Discrete Impuls. Systems, Series A 9 (2002), 165-176. MR 1898309, Zbl 1022.45007.
- Existence principles for inclusions of Hammerstein type involving noncompact acyclic multivalued maps, (with J.-F. Couchouron), Electron. J. Differential Equations. 2002 (2002), no.4, 1-21. MR: 1872799, Zbl 0991.47050.
- The continuation principle for generalized contractions, Bull. Appl. Comput. Math. (Budapest) 96-C (2001), 367-373.
- Existence criteria for integral equations in Banach spaces, (with D. O’Regan), J. Inequal. Appl. 6 (2001), 77-97. MR 2003c:45007, Zbl 0993.45011.
- Convexity and quadratic monotone approximation in delay differential equations, Rev. Anal. Numér. Théor. Approx. 30 (2001), 89-93.
- Continuation results for mappings of contractive type, Seminar on Fixed Point Theory Cluj-Napoca 2 (2001), 23-40.
- On the Palais-Smale condition for Hammerstein integral equations in Hilbert spaces, Nonlinear Anal. 47 (2001), 1233-1244. Zbl 1042.47530.
- Fixed point theorems for set-valued maps and existence principles for integral inclusions, (with D. O’Regan), J. Math. Anal. Appl. 245 (2000), 594-612. MR :2001b:47112.
- A Monch type generalization of the Eilenberg-Montgomery fixed point theorem, Seminar on Fixed Point Theory Cluj-Napoca 1 (2000), 69-72.
- Discrete continuation methods for boundary value problems on bounded sets in Banach spaces, J. Comput. Appl. Math. 113 (2000), 267-281.
- Discrete continuation method for nonlinear integral equations in Banach spaces, Pure Math. Appl. 11 (2000), 375-384.
- Periodic solutions of superlinear impulsive differential systems, (with E. Kirr), Commun. Appl. Anal. 3 (1999), 483-502.
- Analysis of some neutral delay differential equations, Studia Univ. Babes-Bolyai Math. 44, no.3 (1999), 67-84.
- Monotone approximation for an integral equation modeling infectious disease, Bull. Appl. Comput. Math. (Budapest), 86-A (1998), 419-426.
- Existence and approximation of positive fixed points of nonexpansive maps, Rev. Anal. Numér. Théor. Approx. 26, no. 1-2 (1997), 203-208.
- Existence theorems for nonlinear problems by continuation methods, Nonlinear Anal. 30 (1997), 3313-3322. MR: 99a:47097.
- Continuation principles for coincidences, Mathematica (Cluj) 39 (62), no. 1 (1997), 103-110. MR: 99c:47103.
- Continuation theorems for maps of Caristi type , Studia Univ. Babeş-Bolyai Math. 41, no. 4 (1996), 101-106. MR: 1 644 186.
- On the continuation principle for nonexpansive maps, Studia Univ. Babeş-Bolyai Math. 41, no. 3 (1996), 85-89. MR: 1 644 466.
- Monotone technique to the initial values problem for a delay integral equation from biomathematics, Studia Univ. Babeş-Bolyai Math. 40, no. 2 (1995), 63-73. MR: 98a:34067.
- A Granas type approach to some continuation theorems and periodic boundary value problems with impulses, Topol. Methods Nonlinear Anal. 5 (1995), 385-396. MR: 97a:34028.
- Periodic solutions for an integral equation from biomathematics via Leray-Schauder principle, Studia Univ. Babeş-Bolyai Math. 39, no. 1 (1994), 47-58. MR: 98c:45019a.
- On some fixed point theorems of Deimling, Nonlinear Anal. 23 (1994), 1315-1320. MR: 96b:47059.
- On the reverse of the Krasnoselskii-Browder boundary inequality, Studia Univ. Babeş-Bolyai Math. 38, no. 2 (1993), 41-55. ZB: 828.47055.
- On the topological transversality principle, Nonlinear Anal. 20 (1993), 1-9. MR: 94a:58028.
- Note on an abstract continuation theorem, Studia Univ. Babeş-Bolyai Math. 37, no. 2 (1992), 85-90. MR: 95m:58018.
- Quasiconvex functions of higher order and the behavior of some nonlinear functionals, Rev. Anal. Numér. Théor. Approx. 21, no. 2 (1992), 191-193. MR: 94g:26016.
- Generalized topological transversality and existence theorems, Libertas Math. 11 (1991), 65-79. MR: 93a:54037.
- Generalized topological transversality and mappings of monotone type, Studia Univ. Babeş-Bolyai Math. 35, no. 2 (1990), 44-50. MR: 94g:47067.
- Measure of noncompactness and second order differential equations with deviating argument, Studia Univ. Babeş -Bolyai Math.,
**34**(1989) no. 2, 25-35. MR: 91k:34094. - Convex functions of order n and P_{n}-simple functionals, Rev. Anal. Numér. Théor. Approx.,
**18**(1989) no. 2, pp. 161-170. MR: 92d:41048. - Maximal pseudomonotonicity of generalized subdifferentials of explicitly quasiconvex functions, Rev. Anal. Numér. Théor. Approx.,
**17**(1988) no. 1, pp. 53-62. MR: 90a:90215. - On some properties of K-monotone operators, Rev. Anal. Numér. Théor. Approx.,
**16**(1987) no. 1, pp. 69-76. MR: 89d:47119. - A K-monotone best approximation operator which is neither monotone and (essentially) nor (o)-monotone, Rev. Anal. Numér. Théor. Approx.,
**15**(1986) no. 2, pp. 155-162. MR: 88h:41046. - New estimates of the degree of the comonotone interpolating polynomials, Rev. Anal. Numér. Théor. Approx.,
**15**(1986) no. 1, pp. 65-68. MR: 88c:41011. - Piecewise convex interpolation, Rev. Anal. Numér. Théor. Approx. 14 (1985) no. 2, pp. 123-126. MR: 87m:41004.
- Estimates of the degree of comonotone interpolating polynomials, Rev. Anal. Numér. Théor. Approx.,
**11**(1982) nos. 1-2, pp. 139-145. MR: 84i:41003. - Interpolating convex polynomials, Rev. Anal. Numér. Théor. Approx.,
**10**(1981) no. 2, 205-209. MR: 83k:41005. - Sur l’axiomatique des espaces à convexité, Rev. Anal. Numér. Théor. Approx.,
**9**(1980) no. 2, 95-103. MR: 83c:52003. - Le théorème des contractions dans des espaces syntopogènes, Rev. Anal. Numér. Théor. Approx. 9, no. 1 (1980), 113-123. MR: 82i:54008.

## Scientific papers in volumes/proceedings:

- A variational analogue of Krasnoselskii’s cone fixed point theory, in Nonlinear Analysis and Boundary Value Problems, Eds.: I. Area, A. Cabada, J. Á. Cid, D. Franco, E. Liz, R. López Pouso, R. Rodríguez López, Springer Proceedings in Mathematics & Statistics 292, Springer, 2019, 1-18.
- Theoretical models of hematopoietic cell dynamics related to bone marrow transplantation (with D. Dima, C. Tomuleasa, M-A Serban, L-G Parajdi), in Frontiers in Stem Cell and Regenerative Medicine Research, Volume 8, Eds.: Atta-ur-Rahman, Shazia Anjum, DOI:10.2174/97816810858901180801, Bentham Science, Sharjah, UAE, 2018, pp 202-241.
- Compression-expansion critical point theory in conical shells, Nonlinear Analysis and Variational Problems: In Honor of George Isac, P.M. Pardos, Th.M. Rassias, A.A. Khan eds., Springer, New York, 2009, pp 135-146.
- Componentwise compression-expansion conditions for systems of nonlinear operator equations and applications, AIP Conference Proceedings Volume 1124, Mathematical Models in Engineering, Biology and Medicine: International Conference on Boundary Value Problems: Mathematical Models in Engineering, Biology and Medicine, Santiago de Compostela (Spain), 16 -19 September 2008, ISBN: 978-0-7354-0660-5, Eds.: A. Cabada, E. Liz, J.J. Nieto, 284-293.
- Localization of critical points via mountain pass type theorems, in Critical Point Theory and Its Applications, Proceedings of the International Summer School on Critical Point Theory and Applications Cluj-Napoca, July 9th-July 13th 2007, Cs. Varga, A. Kristaly and P.A. Blaga eds., Casa Cartii de Stiinta, Cluj-Napoca, 2007, 53-67.
- Positive solutions of semi-linear elliptic problems via Krasnoselskii type theorems in cones and Harnack’s inequality, in “Mathematical Analysis ans Applications”, eds. V. Radulescu and C. Niculescu, Amer. Inst. Physics, AIP Conference Proceedings, Volume 835, 2006, 125-132. MR2258649.
- Inequalities and compactness, In: “Inequalities Theory and Applications”, Y.J. Cho, J.K. Kim, S.S. Dragomir eds., Nova Science Publ., Huntington-New York, 2001, 257-271. MR 2065320.
- Analysis of a nonlinear integral equation modelling infection diseases, In: “Proceedings of the International Conference on Analysis and Numerical Computation, Timişoara, May 19-21, 1997”, Şt. Balint ed., West Univ. of Timişoara, 1997, 178-195.
- Monotone iterations for decreasing maps in ordered Banach spaces, In: “Proceedings of the Scientific Communications Meeting of Aurel Vlaicu University, Vol 14A (Arad-1996)”, Aurel Vlaicu Univ. of Arad, 1996, 105-108. MR: 1 667 979.
- Existence results for nonlinear boundary value problems under nonresonance conditions, In: “Qualitative Problems for Differential Equations and Control Theory”, C. Corduneanu ed., World Sci. Publishing, River Edge, 1995, 263-273. MR: 96j:35083.
- Foundations of the continuation principles of Leray-Schauder type, In: “Proceedings of the 23rd Conference on Geometry and Topology (Cluj-1993)”, D. Andrica and P. Enghiş eds., Babeş-Bolyai Univ., Cluj, 1994, 136-140. MR: 96m:47113.
- Positive solutions of the initial value problem for an integral equation modeling infectious disease, Babeş-Bolyai Univ., Faculty of Math. Comp. Sci., Research Sem. 3 (1991), I.A. Rus ed., 25-30. MR: 94a:45022.
- Topological transversality and boundary problems for second order functional differential equations, In: “Differential Equations and Control Theory”, V. Barbu ed., Pitman Res. Notes Math. Ser., 250, Longman Sci. Tech., Harlow, 1991, 283-288. MR: 1 157 195.
- Some remarks on Clarke generalized gradient of quasiconvex functions, Babeş-Bolyai Univ., Faculty of Math. Comp. Sci., Research Sem. 6 (1990), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1990), 197-200.
- On the quasiconvex functions of higher order, Babeş-Bolyai Univ., Faculty of Math. Phys., Research Sem. 6 (1989), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1989), 275-282. MR: 91g:26016.
- Topological transversality, perturbation theorems and second order differential equations, Babeş-Bolyai Univ., Faculty of Math. Phys., Research Sem. 3 (1989), 149-164. MR: 92i:47084.
- Nonlinear boundary value problems for infinite systems of second-order functional differential equations,Babeş-Bolyai Univ.,Faculty of Math. Phys., Research Sem. 8 (1988), 17-30. MR: 90c:34070.
- A fixed point theorem of Maia type in syntopogeneous spaces, Babeş-Bolyai Univ., Faculty of Math. Phys., Research Sem. 3 (1988), 49-70. MR: 90d:54089.
- Fonctions convexes et fonctionnelles de forme simple, Babeş-Bolyai Univ., Faculty of Math. Phys., Research Sem. 6 (1988), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1988), 269-274. MR: 90c:26020.
- Quasiconvexity, generalized subdifferential and pseudomonotone mappings, Babeş-Bolyai Univ., Faculty of Math. Phys., Research Sem. 6 (1987), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1987), 261-272. MR: 90c:47069.
- Sur une théorie de l’allure et ses conséquences, Babeş-Bolyai Univ., Faculty of Math. Phys., Research Sem. 6 (1987), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1987), 31-48. MR: 90d:26020.
- Monotonicity properties of the best approximation operators, Babeş-Bolyai Univ., Faculty of Math., Research Sem. 7 (1986), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1986), 223-226.
- Quasi-convexity in linear spaces, Babeş-Bolyai Univ., Faculty of Math., Research Sem. 6 (1985), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1985), 159-164. MR: 842 231.
- A mean theorem concerning the behaviour of some nonlinear functionals, Seminarul Itinerant de Ecuaţii Funcţionale, Aproximare şi Convexitate, Iaşi, 1985, 18-25.
- Sur une notion de quasi-convexité dans des espaces abstraits, Babeş-Bolyai Univ., Faculty of Math., Research Sem. 6 (1984), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1984), 143-150. MR: 86h:52001.
- A dual proof for the linearization of the convexity spaces, Babeş-Bolyai Univ., Faculty of Math., Research Sem. 2 (1983), Itinerant Seminar on Functional Equations, Approximation and Convexity (Cluj-1983), 119-128. MR: 86g:52004.

Conferences attended:

- NATO Advanced Study Institute, 33rd session: Topological Methods in Differential Equations and Inclusions, July 11-22, 1994, Montreal, Canada (special talk);
- International Congress of Mathematicians, August 3-11, 1994, Zürich, Switzerland;
- Second World Congress of Nonlinear Analysts, July 10-17, 1996, Athens, Greece (invited talk);
- 4ème Colloque franco-roumain, 31 août-4 septembre, 1998, Metz, France (plenary invited talk);
- 3rd Hungarian-Romanian Joint Conference on Mathematics and Computer Science, June 6-12, 1999, Visegrád, Hungary;
- Third World Congress of Nonlinear Analysts, July 19-26, 2000, Catania, Italy (invited talk);
- 5ème Colloque franco-roumain, 28 août-1er septembre, 2000, Constanţa;
- International Conference on Nonlinear Operators, Differential Equations and Applications, September 12-15, 2001, Cluj-Napoca;
- 5th Hungarian-Romanian Joint Conference on Mathematics and Computer Science, June 9-12, 2004, Debrecen, Hungary;
- International Conference on Nonlinear Operators, Differential Equations and Applications, August 24-27, 2004, Cluj–Napoca;
- 7ème Colloque franco-roumain, 30 août-3 septembre, 2004, Craiova (plenary invited lecture);
- International Conference on Mathematical Analysis and Applications, September 23-24, 2005, Craiova (invited talk);
- International Conference on Nonlinear Operators, Differential Equations and Applications, July 4-8, 2007, Cluj-Napoca;
- 7th Hungarian-Romanian Joint Conf. Math. Comput. Sc., July 3-6, 2008, Cluj-Napoca (plenary invited lecture);
- International Conference on Boundary Value Problems, September 16-19, 2008, Santiago de Compostela, Spain (invited talk);
- Romanian-German Symposium on Mathematics and Its Applications, May 14-17, 2009, Sibiu;
- 10ème Colloque Franco-Roumain de Mathématiques Appliquées, 26-31 août, 2010, Poitiers, France;
- International Conference on Nonlinear Operators, Differential Equations and Applications, July 5-8, 2011, Cluj-Napoca;
- International Conference on Fixed Point Theory and Its Applications (ICFPTA-2012), July 9-15, 2012, Cluj-Napoca;
- Summer School “Analytical and Computer Assisted Methods in Mathematical Models”, September 9-23, 2012, Freudenstadt, Germany (lectures);
- International Workshop on Fixed Point Theory and Applications, October 11-13, 2012, Istanbul, Turkey;
- Workshop: Positive Solutions to Differential Equations, May 6-10, 2013, Torun, Poland (invited talks);
- Academic Days of Timisoara, Workshop on Geometry and PDEs, May 23-24, 2013,Timisoara;
- Faculty of Science, University of Sfax, June 19-26, 2013, Sfax, Tunisia;
- Anatolian Communications in Nonlinear Analysis, July 3-6, 2013, Bolu, Turkey (invited talk);
- Summer School “Analytical and Computer Assisted Methods in Mathematical Models”, September 1-15, 2013, Hojduszoboszlo, Hungary (lectures);
- Dipartimento di Matematica e Informatica, Universita degli Studi di Perugia, February 12, 2014Perugia, Italy;
- Workshop: Lectures in Nonlinear Analysis and Differential Equations, March 24-28, 2014, Cosenza, Italy (invited lectures);
- Workshop in Geometry and PDEs, June 6-7, 2014, Timisoara (invited talk);
- Minisymposium on Fixed Point Theory and Applications, June 1-7, 2014, Baia-Mare (invited talk);
- Workshop in Geometry and PDEs, May 29-31, 2015, Timisoara (invited talk);
- The Eighth Congress of Romanian Mathematicians, June 26-July 1, 2015, Iasi;
- International Conference on Nonlinear Operators, Differential Equations and Applications, July 14-17, 2015, Cluj-Napoca;
- Symposium on Nolinear Analysis SNA2015, September 14-18, 2015, Torun, Poland (invited talk);
- Scientific Conference UR & US’15, October 9-10, 2015, Ruse, Bulgaria (invited talk);
- Workshop in Geometry and PDEs, June 10-11, 2016, Timisoara (keynote speaker);
- Workshop of Geometry and PDEs, June 13-14, 2017, Timisoara (keynote speaker);
- Scientific Conference UR & US’16, October, 2017, Ruse, Bulgaria (invited talk);
- International Symposium “Research and Education in an Innovation Era”, May 17-20, 2018, Arad (invited speaker);
- International Conference on Mathematics and Computer Science, June 14-16, 2018, Brasov;
- International Conference on Nonlinear Analysis and Boundary Value Problems, September 4-7, 2018, Santiago de Compostela, Spain (main speaker);
- Workshop of Geometry and PDEs, October 12-13, 2018, Timisoara.56;
- International Symposium “Research and Education in an Innovation Era”, 8th Edition, Arad, 23-25 May, 2019 (invited speaker);
- Workshop on Analysis, PDEs and Mechanics, Bucharest 30 May 2019;
- Italian-Romanian Colloquium of Differential Equations and Applications, Udine, 10-12 April, 2019 (invited speaker);
- Fixed Point Theory, Graph Theory and Optimization: Foundations and Integrative Approaches, Dhahran, Saudi Arabia, 18-19 December, 2019 (invited speaker);
- Zilele Academice Clujene 2021, 28 octombrie 2021;
- Analysis seminar, West Virginia University, Morgantown, 17 November 2021;
- Current Trends in Applied Mathematics, Iasi, 20 November 2021;
- Workshop: Geometric Function Theory in Several Complex Variables and Complex Banach Spaces, Cluj-Napoca, 1-3 December 2021.