Kirk, W. A.; Shahzad, Naseer Orbital fixed point conditions in geodesic spaces. (English) Zbl 1461.54091 Fixed Point Theory 21, No. 1, 221-238 (2020). Reviewer: Jarosław Górnicki (Rzeszów) MSC: 54H25 47H10 47H09 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, Fixed Point Theory 21, No. 1, 221--238 (2020; Zbl 1461.54091) Full Text: Link
Kirk, W. A.; Shahzad, Naseer Hyperbolic spaces and directional contractions. (English) Zbl 1470.54075 Bull. Math. Sci. 9, No. 3, Article ID 1950021, 49 p. (2019). Reviewer: Jarosław Górnicki (Rzeszów) MSC: 54H25 47H10 47H09 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, Bull. Math. Sci. 9, No. 3, Article ID 1950021, 49 p. (2019; Zbl 1470.54075) Full Text: DOI
Kirk, W. A. Remarks on nonexpansive mappings and related asymptotic conditions. (English) Zbl 1477.47042 J. Nonlinear Convex Anal. 18, No. 1, 1-15 (2017). MSC: 47H09 47H10 47-02 PDFBibTeX XMLCite \textit{W. A. Kirk}, J. Nonlinear Convex Anal. 18, No. 1, 1--15 (2017; Zbl 1477.47042) Full Text: Link
Kirk, William A.; Shahzad, Naseer Remarks on Pasicki’s abstract metric spaces and Lifshits’s constant. (English) Zbl 1382.54026 Fixed Point Theory 18, No. 2, 651-662 (2017). MSC: 54H25 47H09 47H10 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, Fixed Point Theory 18, No. 2, 651--662 (2017; Zbl 1382.54026) Full Text: DOI
Kirk, W. A.; Shahzad, Naseer Fixed points of locally nonexpansive mappings in geodesic spaces. (English) Zbl 1354.54043 J. Math. Anal. Appl. 447, No. 2, 705-715 (2017). Reviewer: Zdzisław Dzedzej (Gdansk) MSC: 54H25 47H09 53C70 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, J. Math. Anal. Appl. 447, No. 2, 705--715 (2017; Zbl 1354.54043) Full Text: DOI
Kirk, W. A.; Shahzad, Naseer Contractive conditions in semimetric spaces. (English) Zbl 1366.54015 J. Nonlinear Convex Anal. 17, No. 11, 2197-2213 (2016). MSC: 54H25 47H09 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, J. Nonlinear Convex Anal. 17, No. 11, 2197--2213 (2016; Zbl 1366.54015) Full Text: Link
Kirk, W. A.; Shahzad, Naseer Uniformly Lipschitzian mappings in \(\mathbb{R}\)-trees. (English) Zbl 1329.05067 J. Nonlinear Convex Anal. 16, No. 8, 1699-1705 (2015). MSC: 05C05 54H25 05C85 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, J. Nonlinear Convex Anal. 16, No. 8, 1699--1705 (2015; Zbl 1329.05067) Full Text: Link
Kirk, W. A.; Shahzad, Naseer Fixed points and Cauchy sequences in semimetric spaces. (English) Zbl 1326.54045 J. Fixed Point Theory Appl. 17, No. 3, 541-555 (2015). MSC: 54H25 47H10 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, J. Fixed Point Theory Appl. 17, No. 3, 541--555 (2015; Zbl 1326.54045) Full Text: DOI
Alghamdi, Maryam A.; Kirk, William A.; Shahzad, Naseer Metric fixed point theory for nonexpansive mappings defined on unbounded sets. (English) Zbl 1310.54034 Fixed Point Theory Appl. 2014, Paper No. 143, 12 p. (2014). MSC: 54H25 47H09 PDFBibTeX XMLCite \textit{M. A. Alghamdi} et al., Fixed Point Theory Appl. 2014, Paper No. 143, 12 p. (2014; Zbl 1310.54034) Full Text: DOI
Alghamdi, Maryam A.; Kirk, W. A.; Shahzad, Naseer Locally nonexpansive mappings in geodesic and length spaces. (English) Zbl 1293.53051 Topology Appl. 173, 59-73 (2014). MSC: 53C22 53C70 54H25 47H09 47H10 PDFBibTeX XMLCite \textit{M. A. Alghamdi} et al., Topology Appl. 173, 59--73 (2014; Zbl 1293.53051) Full Text: DOI
Shahzad, Naseer; Kirk, W. A.; Alghamdi, Maryam A. Fixed points and best approximation in arcwise connected spaces. (English) Zbl 1295.54086 Topology Appl. 166, 108-113 (2014). Reviewer: Bhavana Deshpande (Ratlam) MSC: 54H25 PDFBibTeX XMLCite \textit{N. Shahzad} et al., Topology Appl. 166, 108--113 (2014; Zbl 1295.54086) Full Text: DOI
Kirk, William A.; Shahzad, Naseer Generalized metrics and Caristi’s theorem. (English) Zbl 1295.54060 Fixed Point Theory Appl. 2013, Paper No. 129, 9 p. (2013); erratum ibid. 2014, Paper No. 177, 3 p. (2014). MSC: 54H25 47H10 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, Fixed Point Theory Appl. 2013, Paper No. 129, 9 p. (2013; Zbl 1295.54060) Full Text: DOI
Kirk, W. A.; Shahzad, N. Some fixed point results in ultrametric spaces. (English) Zbl 1252.54038 Topology Appl. 159, No. 15, 3327-3334 (2012). Reviewer: Zoran Kadelburg (Beograd) MSC: 54H25 54E40 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{N. Shahzad}, Topology Appl. 159, No. 15, 3327--3334 (2012; Zbl 1252.54038) Full Text: DOI
Kirk, W. A. Remarks on approximate fixed points. (English) Zbl 1255.54023 Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 75, No. 12, 4632-4636 (2012). Reviewer: Dariusz Bugajewski (Poznań) MSC: 54H25 PDFBibTeX XMLCite \textit{W. A. Kirk}, Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 75, No. 12, 4632--4636 (2012; Zbl 1255.54023) Full Text: DOI
Kirk, W. A. Metric fixed point theory: old problems and new directions. (English) Zbl 1216.47085 Fixed Point Theory 11, No. 1, 45-58 (2010). Reviewer: Zoran Kadelburg (Beograd) MSC: 47H10 47H09 54H25 05C05 PDFBibTeX XMLCite \textit{W. A. Kirk}, Fixed Point Theory 11, No. 1, 45--58 (2010; Zbl 1216.47085)
Kirk, William A.; Panyanak, Bancha Remarks on best approximation in \(\mathbb R\)-trees. (English) Zbl 1191.54040 Ann. Univ. Mariae Curie-Skłodowska, Sect. A 63, 133-138 (2009). MSC: 54H25 54E40 05C05 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{B. Panyanak}, Ann. Univ. Mariae Curie-Skłodowska, Sect. A 63, 133--138 (2009; Zbl 1191.54040) Full Text: DOI
Kirk, W. A. Approximate fixed points of nonexpansive maps. (English) Zbl 1198.47072 Fixed Point Theory 10, No. 2, 275-288 (2009). Reviewer: Jarosław Górnicki (Rzeszów) MSC: 47H09 54H25 PDFBibTeX XMLCite \textit{W. A. Kirk}, Fixed Point Theory 10, No. 2, 275--288 (2009; Zbl 1198.47072)
Kirk, W. A. Universal nonexpansive maps. (English) Zbl 1185.47056 Dhompongsa, Sompong (ed.) et al., Fixed point theory and its applications. Proceedings of the 8th international conference on fixed point theory and its applications (ICFPTA), Chiang Mai, Thailand, July 16–22, 2007. Yokohama: Yokohama Publishers (ISBN 978-4-946552-31-1/hbk). 95-101 (2008). Reviewer: In-Sook Kim (Suwon) MSC: 47H09 54H25 PDFBibTeX XMLCite \textit{W. A. Kirk}, in: Fixed point theory and its applications. Proceedings of the 8th international conference on fixed point theory and its applications (ICFPTA), Chiang Mai, Thailand, July 16--22, 2007. Yokohama: Yokohama Publishers. 95--101 (2008; Zbl 1185.47056)
Goebel, Kazimierz; Kirk, W. A. Some problems in metric fixed point theory. (English) Zbl 1166.47053 J. Fixed Point Theory Appl. 4, No. 1, 13-25 (2008). Reviewer: Hemant Kumar Nashine (Raipur) MSC: 47H10 54H25 05C05 47H09 47-02 PDFBibTeX XMLCite \textit{K. Goebel} and \textit{W. A. Kirk}, J. Fixed Point Theory Appl. 4, No. 1, 13--25 (2008; Zbl 1166.47053) Full Text: DOI
Kirk, W. A. Some recent results in metric fixed point theory. (English) Zbl 1139.05315 J. Fixed Point Theory Appl. 2, No. 2, 195-207 (2007). MSC: 05C12 54H25 47H09 PDFBibTeX XMLCite \textit{W. A. Kirk}, J. Fixed Point Theory Appl. 2, No. 2, 195--207 (2007; Zbl 1139.05315) Full Text: DOI
Kirk, W. A.; Panyanak, B. Best approximation in \(\mathbb R\)-trees. (English) Zbl 1132.54025 Numer. Funct. Anal. Optim. 28, No. 5-6, 681-690 (2007); erratum ibid. 30, No. 3-4, 403 (2009). Reviewer: Nawab Hussain (Jeddah) MSC: 54H25 54E40 05C05 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{B. Panyanak}, Numer. Funct. Anal. Optim. 28, No. 5--6, 681--690 (2007; Zbl 1132.54025) Full Text: DOI
Kaewcharoen, A.; Kirk, W. A. Proximinality in geodesic spaces. (English) Zbl 1141.51011 Abstr. Appl. Anal. 2006, Article ID 43591, 10 p. (2006). Reviewer: Hang Lau (Montréal) MSC: 51F99 51K05 53C22 47H10 46B20 PDFBibTeX XMLCite \textit{A. Kaewcharoen} and \textit{W. A. Kirk}, Abstr. Appl. Anal. 2006, Article ID 43591, 10 p. (2006; Zbl 1141.51011) Full Text: DOI EuDML
Kirk, W. A. Nonexpansive retracts and minimal invariant sets. (English) Zbl 1113.47042 Fetter Nathansky, Helga (ed.) et al., Proceedings of the 7th international conference on fixed-point theory and its applications, Guanajuato, Mexico, July 17–23, 2005. Yokohama: Yokohama Publishers (ISBN 4-946552-25-1/pbk). 161-169 (2006). Reviewer: Mircea Balaj (Oradea) MSC: 47H09 47H10 46B20 54H25 54C15 PDFBibTeX XMLCite \textit{W. A. Kirk}, in: Proceedings of the 7th international conference on fixed-point theory and its applications, Guanajuato, Mexico, July 17--23, 2005. Yokohama: Yokohama Publishers. 161--169 (2006; Zbl 1113.47042)
Dhompongsa, S.; Kirk, W. A.; Sims, Brailey Fixed points of uniformly Lipschitzian mappings. (English) Zbl 1105.47050 Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 65, No. 4, 762-772 (2006). Reviewer: Wojciech Kryszewski (Toruń) MSC: 47H10 54H25 54E40 47H09 PDFBibTeX XMLCite \textit{S. Dhompongsa} et al., Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 65, No. 4, 762--772 (2006; Zbl 1105.47050) Full Text: DOI
Kirk, W. A.; Sims, Brailey An ultrafilter approach to locally almost nonexpansive maps. (English) Zbl 1225.47063 Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 63, No. 5-7, e1241-e1251 (2005). MSC: 47H09 47H10 54H25 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{B. Sims}, Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 63, No. 5--7, e1241--e1251 (2005; Zbl 1225.47063) Full Text: DOI
Eldred, A. Anthony; Kirk, W. A.; Veeramani, P. Proximal normal structure and relatively nonexpansive mappings. (English) Zbl 1078.47013 Stud. Math. 171, No. 3, 283-293 (2005). MSC: 47H09 46B20 47H10 47J25 PDFBibTeX XMLCite \textit{A. A. Eldred} et al., Stud. Math. 171, No. 3, 283--293 (2005; Zbl 1078.47013) Full Text: DOI
Kirk, W. A. Geodesic geometry and fixed point theory. II. (English) Zbl 1083.53061 García-Falset, Jesús (ed.) et al., Proceedings of the international conference on fixed-point theory and its applications, Valencia, Spain, July 13–19, 2003. Yokohama: Yokohama Publishers (ISBN 4-946552-13-8/hbk). 113-142 (2004). Reviewer: I. G. Nikolaev (Urbana) MSC: 53C45 58C30 05C75 47H09 54H25 51K10 05C05 PDFBibTeX XMLCite \textit{W. A. Kirk}, in: Proceedings of the international conference on fixed-point theory and its applications, Valencia, Spain, July 13--19, 2003. Yokohama: Yokohama Publishers. 113--142 (2004; Zbl 1083.53061)
Kirk, W. A. The approximate fixed point property and uniform normal structure in hyperconvex spaces. (English) Zbl 1264.47056 Takahashi, Wataru (ed.) et al., Proceedings of the 2nd international conference on nonlinear analysis and convex analysis (NACA2001), Hirosaki, Japan, July 30–August 2, 2001. Yokohama: Yokohama Publishers (ISBN 4-946552-09-X/hbk). 179-190 (2003). MSC: 47H09 47H04 54H25 PDFBibTeX XMLCite \textit{W. A. Kirk}, in: Proceedings of the 2nd international conference on nonlinear analysis and convex analysis (NACA2001), Hirosaki, Japan, July 30--August 2, 2001. Yokohama: Yokohama Publishers. 179--190 (2003; Zbl 1264.47056)
Espínola, R.; Kirk, W. A. Set-valued contractions and fixed points. (English) Zbl 1025.47032 Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 54, No. 3, 485-494 (2003). Reviewer: V.Popa (Bacau) MSC: 47H10 47H04 PDFBibTeX XMLCite \textit{R. Espínola} and \textit{W. A. Kirk}, Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 54, No. 3, 485--494 (2003; Zbl 1025.47032) Full Text: DOI
Kirk, W. A. Brouwer’s fixed point theorem. (English) Zbl 1069.55500 Cubo Mat. Educ. 4, No. 1, 177-194 (2002). MSC: 55M20 54H25 55-03 54-03 01A60 PDFBibTeX XMLCite \textit{W. A. Kirk}, Cubo Mat. Educ. 4, No. 1, 177--194 (2002; Zbl 1069.55500)
Goebel, Kazimierz; Kirk, W. A. Classical theory of nonexpansive mappings. (English) Zbl 1035.47033 Kirk, William A. (ed.) et al., Handbook of metric fixed point theory. Dordrecht: Kluwer Academic Publishers (ISBN 0-7923-7073-2/hbk). 49-91 (2001). MSC: 47H09 54H25 54E40 47-02 47J25 47H10 PDFBibTeX XMLCite \textit{K. Goebel} and \textit{W. A. Kirk}, in: Handbook of metric fixed point theory. Dordrecht: Kluwer Academic Publishers. 49--91 (2001; Zbl 1035.47033)
Kim, Eun Suk; Kirk, W. A. A note on Picard iterates of nonexpansive mappings. (English) Zbl 0973.47040 Ann. Pol. Math. 76, No. 3, 189-196 (2001). MSC: 47H10 46B20 47H09 PDFBibTeX XMLCite \textit{E. S. Kim} and \textit{W. A. Kirk}, Ann. Pol. Math. 76, No. 3, 189--196 (2001; Zbl 0973.47040) Full Text: DOI
Khamsi, M. A.; Kirk, W. A.; Martinez Yañez, Carlos Fixed point and selection theorems in hyperconvex spaces. (English) Zbl 0959.47032 Proc. Am. Math. Soc. 128, No. 11, 3275-3283 (2000). Reviewer: J.Myjak (L’Aquila) MSC: 47H10 47H04 54H25 47H09 54E40 PDFBibTeX XMLCite \textit{M. A. Khamsi} et al., Proc. Am. Math. Soc. 128, No. 11, 3275--3283 (2000; Zbl 0959.47032) Full Text: DOI
Kirk, William A. Remarks on approximation and approximate fixed points in metric fixed point theory. (English) Zbl 1012.47035 Ann. Univ. Mariae Curie-Skłodowska, Sect. A 51, No. 2, 167-178 (1997). MSC: 47H10 54H25 PDFBibTeX XMLCite \textit{W. A. Kirk}, Ann. Univ. Mariae Curie-Skłodowska, Sect. A 51, No. 2, 167--178 (1997; Zbl 1012.47035)
Jaworowski, Jan; Kirk, William A.; Park, Sehie Antipodal points and fixed points. (English) Zbl 0842.54040 Lecture Notes Series, Seoul. 28. Seoul: National Univ. iv, 97 p. (1995). Reviewer: I.A.Rus (Cluj-Napoca) MSC: 54H25 47H10 47H09 58C30 55M20 PDFBibTeX XMLCite \textit{J. Jaworowski} et al., Antipodal points and fixed points. Seoul: National Univ. (1995; Zbl 0842.54040)
Kirk, W. A. Approximate fixed points for mappings in Banach spaces. (English) Zbl 0589.47053 Nonlinear functional analysis and its applications, Proc. NATO Adv. Study Inst., Maratea/Italy 1985, NATO ASI Ser., Ser. C 173, 299-303 (1986). MSC: 47H10 PDFBibTeX XML
Kirk, W. A. Fixed point theory for nonexpansive mappings. II. (English) Zbl 0511.47037 Contemp. Math. 18, 121-140 (1983). MSC: 47H10 47H09 54H25 PDFBibTeX XMLCite \textit{W. A. Kirk}, Contemp. Math. 18, 121--140 (1983; Zbl 0511.47037) Full Text: DOI
Bruck, R. E.; Kirk, W. A.; Reich, S. Strong and weak convergence theorems for locally nonexpansive mappings in Banach spaces. (English) Zbl 0485.47040 Nonlinear Anal., Theory Methods Appl. 6, 151-155 (1982). MSC: 47H09 PDFBibTeX XMLCite \textit{R. E. Bruck} et al., Nonlinear Anal., Theory Methods Appl. 6, 151--155 (1982; Zbl 0485.47040) Full Text: DOI
Kirk, W. A. Fixed point theory for nonexpansive mappings. (English) Zbl 0479.47049 Fixed point theory, Proc. Conf., Sherbrooke/Can. 1980, Lect. Notes Math. 886, 484-505 (1981). MSC: 47H10 47H09 PDFBibTeX XML
Kirk, W. A.; Morales, Claudio On the approximation of fixed points of locally nonexpansive mappings. (English) Zbl 0475.47041 Can. Math. Bull. 24, 441-445 (1981). MSC: 47H10 47J05 47J25 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{C. Morales}, Can. Math. Bull. 24, 441--445 (1981; Zbl 0475.47041) Full Text: DOI
Kirk, W. A. Locally nonexpansive mappings in Banach spaces. (English) Zbl 0475.47040 Fixed point theory, Proc. Conf., Sherbrooke/Can. 1980, Lect. Notes Math. 886, 178-198 (1981). MSC: 47H10 47H09 47J05 47J25 PDFBibTeX XML
Kirk, W. A.; Ray, William O. Fixed-point theorems for mappings defined on unbounded sets in Banach spaces. (English) Zbl 0412.47033 Stud. Math. 64, 127-138 (1979). MSC: 47H10 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{W. O. Ray}, Stud. Math. 64, 127--138 (1979; Zbl 0412.47033) Full Text: DOI EuDML
Kirk, W. A.; Royalty, W. D. Fixed-point theorems for certain nonlinear nonexpansive mappings. (English) Zbl 0221.47039 Ill. J. Math. 15, 656-663 (1971). MSC: 47H09 47H10 55M20 54H25 PDFBibTeX XMLCite \textit{W. A. Kirk} and \textit{W. D. Royalty}, Ill. J. Math. 15, 656--663 (1971; Zbl 0221.47039)