Research output: Contribution to journal › Article › peer-review
Inner and outer smooth approximation of convex hypersurfaces. When is it possible? / Azagra, Daniel; Столяров, Дмитрий Михайлович.
In: Nonlinear Analysis, Theory, Methods and Applications, Vol. 230, 113225, 01.05.2023.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Inner and outer smooth approximation of convex hypersurfaces. When is it possible?
AU - Azagra, Daniel
AU - Столяров, Дмитрий Михайлович
PY - 2023/5/1
Y1 - 2023/5/1
N2 - Let S be a convex hypersurface (the boundary of a closed convex set V with nonempty interior) in Rn. We prove that S contains no lines if and only if for every open set U⊃S there exists a real-analytic convex hypersurface SU⊂U∩int(V). We also show that S contains no rays if and only if for every open set U⊃S there exists a real-analytic convex hypersurface SU⊂U∖V. Moreover, in both cases, SU can be taken strongly convex. We also establish similar results for convex functions defined on open convex subsets of Rn, completely characterizing the class of convex functions that can be approximated in the C0-fine topology by smooth convex functions from above or from below. We also provide similar results for C1-fine approximations.
AB - Let S be a convex hypersurface (the boundary of a closed convex set V with nonempty interior) in Rn. We prove that S contains no lines if and only if for every open set U⊃S there exists a real-analytic convex hypersurface SU⊂U∩int(V). We also show that S contains no rays if and only if for every open set U⊃S there exists a real-analytic convex hypersurface SU⊂U∖V. Moreover, in both cases, SU can be taken strongly convex. We also establish similar results for convex functions defined on open convex subsets of Rn, completely characterizing the class of convex functions that can be approximated in the C0-fine topology by smooth convex functions from above or from below. We also provide similar results for C1-fine approximations.
KW - Convex body
KW - Convex hypersurface
KW - Fine approximation
UR - https://www.mendeley.com/catalogue/cc4d1119-3888-3fe8-b435-b918df1d9881/
U2 - 10.1016/j.na.2023.113225
DO - 10.1016/j.na.2023.113225
M3 - Article
VL - 230
JO - Nonlinear Analysis, Theory, Methods and Applications
JF - Nonlinear Analysis, Theory, Methods and Applications
SN - 0362-546X
M1 - 113225
ER -
ID: 102518688