Abstract
We provide formulae for the \(\varepsilon \)-subdifferential of the integral function \(I_f(x):=\int _T f(t,x) d\mu (t)\), where the integrand \(f:T\times X \rightarrow \overline{\mathbb {R}}\) is measurable in (t, x) and convex in x. The state variable lies in a locally convex space, possibly non-separable, while T is given a structure of a nonnegative complete \(\sigma \)-finite measure space \((T,\mathcal {A},\mu )\). The resulting characterizations are given in terms of the \(\varepsilon \)-subdifferential of the data functions involved in the integrand, f, without requiring any qualification conditions. We also derive new formulas when some usual continuity-type conditions are in force. These results are new even for the finite sum of convex functions and for the finite-dimensional setting.
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Aubin, J.-P., Frankowska, H.: Set-Valued Analysis. Modern Birkhäuser Classics. Birkhäuser Boston Inc, Boston, MA (2009)
Aumann, R.J.: Integrals of set-valued functions. J. Math. Anal. Appl. 12, 1–12 (1965)
Borwein, J.M., Lewis, A.S.: Convex Analysis and Nonlinear Optimization. CMS Books in Mathematics/Ouvrages de Mathématiques de la SMC, vol. 3, 2nd edn. Springer, New York (2006). Theory and examples
Borwein, J.M., Vanderwerff, J.D.: Convex Functions: Constructions, Characterizations and Counterexamples, Volume 109 of Encyclopedia of Mathematics and its Applications. Cambridge University Press, Cambridge (2010)
Borwein, J.M., Yao, L.: Legendre-type integrands and convex integral functions. J. Convex Anal. 21(1), 261–288 (2014)
Bot, R.I., Grad, S.M., Wanka, G.: New constraint qualification and conjugate duality for composed convex optimization problems. J. Optim. Theory Appl. 135(2), 241–255 (2007)
Bourbaki, N.: Éléments de mathématique. VIII. Première partie: Les structures fondamentales de l’analyse. Livre III: Topologie générale. Chapitre IX: Utilisation des nombres réels en topologie générale. Actualités Sci. Ind., no 1045. Hermann et Cie., Paris (1948)
Burachik, R.S., Jeyakumar, V.: A dual condition for the convex subdifferential sum formula with applications. J. Convex Anal. 12(2), 279–290 (2005)
Castaing, C.: Sur les multi-applications mesurables. Rev. Fr. Informat. Rech. Opér. 1(1), 91–126 (1967)
Castaing, C., Valadier, M.: Convex Analysis and Measurable Multifunctions. Lecture Notes in Mathematics, vol. 580. Springer-Verlag, Berlin-New York (1977)
Combari, C., Laghdir, M., Thibault, L.: On subdifferential calculus for convex functions defined on locally convex spaces. Ann. Sci. Math. Québec 23(1), 23–36 (1999)
Correa, R., Hantoute, A., López, M.A.: Towards supremum-sum subdifferential calculus free of qualification conditions. SIAM J. Optim. 26(4), 2219–2234 (2016)
Correa, R., Hantoute, A., López, M.A.: Weaker conditions for subdifferential calculus of convex functions. J. Funct. Anal. 271(5), 1177–1212 (2016)
Correa, R., Hantoute, A., Pérez-Aros, P.: Sequential and exact formulae for the subdifferential of nonconvex integral functionals. ArXiv e-prints (2018). arXiv:2803.05521
Correa, R., Hantoute, A., Pérez-Aros, P.: Characterizations of the subdifferential of convex integral functions under qualification conditions. J. Funct. Anal. 277(1), 227–254 (2019)
Diestel, J., Uhl, Jr. J.J.: Vector measures. American Mathematical Society, Providence, R.I. With a foreword by B. J. Pettis, Mathematical Surveys, No. 15 (1977)
Hantoute, A., López, M.A., Zǎlinescu, C.: Subdifferential calculus rules in convex analysis: a unifying approach via pointwise supremum functions. SIAM J. Optim. 19(2), 863–882 (2008)
Hiriart-Urruty, J.-B., Lemaréchal, C.: Fundamentals of convex analysis. Grundlehren Text Editions. Springer-Verlag, Berlin, (2001). Abridged version of ıt Convex analysis and minimization algorithms. I [Springer, Berlin, 1993; MR1261420 (95m:90001)] and ıt II [ibid.; MR1295240 (95m:90002)]
Hiriart-Urruty, J.-B., Moussaoui, M., Seeger, A., Volle, M.: Subdifferential calculus without qualification conditions, using approximate subdifferentials: a survey. Nonlinear Anal. 24(12), 1727–1754 (1995)
Hu, S., Papageorgiou, N.S.: Handbook of Multivalued Analysis. Volume 419 of Mathematics and its Applications, vol. I. Kluwer Academic Publishers, Dordrecht (1997)
Ioffe, A.D.: Survey of measurable selection theorems: Russian literature supplement. SIAM J. Control Optim. 16(5), 728–732 (1978)
Ioffe, A.D.: Three theorems on subdifferentiation of convex integral functionals. J. Convex Anal. 13(3–4), 759–772 (2006)
Ioffe, A.D., Levin, V.L.: Subdifferentials of convex functions. Trudy Moskov. Mat. Obšč. 26, 3–73 (1972)
Ioffe, A.D., Tikhomirov, V.M.: Duality of convex functions and extremum problems. Russ. Math. Surv. 23(6), 53 (1968)
Laurent, P.-J.: Approximation et Optimisation. Hermann, Paris (1972)
Levin, V.L.: Convex integral functionals and the theory of lifting. Russ. Math. Surv. 30(2), 119 (1975)
Lopez, O., Thibault, L.: Sequential formula for subdifferential of integral sum of convex functions. J. Nonlinear Convex Anal. 9(2), 295–308 (2008)
Mordukhovich, B.S., Sagara, N.: Subdifferentials of nonconvex integral functionals in banach spaces with applications to stochastic dynamic programming. J. Convex Anal. 25(2), 643–673 (2018)
Moreau, J.-J.: Fonctionnelles convexes. Séminaire Jean Leray 2, 1–108 (1967)
Pérez-Aros, P.: Formulae for the conjugate and the subdifferential of the supremum function. J. Optim. Theory Appl. 180(2), 397–427 (2019)
Pérez-Aros, P.: Subdifferential formulae for the supremum of an arbitrary family of functions. SIAM J. Optim. 29(2), 1714–1743 (2019)
Rockafellar, R.T.: Integrals which are convex functionals. Pac. J. Math. 24, 525–539 (1968)
Rockafellar, R.T.: Convex integral functionals and duality. In: Contributions to nonlinear functional analysis (Proc. Sympos., Math. Res. Center, Univ. Wisconsin, Madison, Wis., 1971), pages 215–236. Academic Press, New York (1971)
Rockafellar, R.T.: Integrals which are convex functionals. II. Pac. J. Math. 39, 439–469 (1971)
Rockafellar, R.T.: Integral Functionals, Normal Integrands and Measurable Selections. Lecture Notes in Mathematics, vol. 543. Springer, Berlin (1976)
Rockafellar, R.T.: Convex analysis. Princeton Landmarks in Mathematics. Princeton University Press, Princeton, NJ, Reprint of the 1970 original, Princeton Paperbacks (1997)
Rockafellar, R.T.: Variational Analysis, Volume 317 of Grundlehren der Mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences]. Springer-Verlag, Berlin (1998)
Schwartz, L.: Radon measures on arbitrary topological spaces and cylindrical measures. Published for the Tata Institute of Fundamental Research, Bombay by Oxford University Press, London, Tata Institute of Fundamental Research Studies in Mathematics, No. 6 (1973)
Vallée, C., Zǎlinescu, C.: Series of convex functions: subdifferential, conjugate and applications to entropy minimization. J. Convex Anal. 23(4), 1137–1160 (2016)
Wagner, D.H.: Survey of measurable selection theorems. SIAM J. Control Optim. 15(5), 859–903 (1977)
Wagner, D.H.: Survey of measurable selection theorems: an update. In: Measure theory, Oberwolfach 1979 (Proc. Conf., Oberwolfach, 1979), volume 794 of Lecture Notes in Math., pp. 176–219. Springer, Berlin-New York (1980)
Zǎlinescu, C.: Convex analysis in general vector spaces. World Scientific Publishing Co. Inc., River Edge, NJ (2002)
Acknowledgements
We very much appreciate the insightful suggestions and helpful comments of the referees, which have contributed to improving the current revision of the manuscript.
Funding
This work is partially supported by CONICYT Grants: Fondecyt projects N 1151003, 1190012, 1190110, and 1150909, Proyecto/Grant PIA AFB-170001, CONICYT-PCHA/doctorado Nacional/2014-21140621.
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Correa, R., Hantoute, A. & Pérez-Aros, P. Qualification Conditions-Free Characterizations of the \(\varepsilon \)-Subdifferential of Convex Integral Functions. Appl Math Optim 83, 1709–1737 (2021). https://doi.org/10.1007/s00245-019-09604-y
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DOI: https://doi.org/10.1007/s00245-019-09604-y