Symmetry | Selected Papers from the 2021 Editor’s Choice Articles in the Section “Mathematics and Symmetry/Asymmetry”

1. “Differential Subordination and Superordination Results Using Fractional Integral of Confluent Hypergeometric Function”
by Alina Alb Lupaş and Georgia Irina Oros
Symmetry 2021, 13(2), 327; https://doi.org/10.3390/sym13020327
Available online: https://www.mdpi.com/2073-8994/13/2/327

2. “New Conditions for Univalence of Confluent Hypergeometric Function”
by Georgia Irina Oros
Symmetry 2021, 13(1), 82; https://doi.org/10.3390/sym13010082
Available online: https://www.mdpi.com/2073-8994/13/1/82

3. “Cyclic Control Optimization Algorithm for Stirling Engines”
by Raphael Paul and Karl Heinz Hoffmann
Symmetry 2021, 13(5), 873; https://doi.org/10.3390/sym13050873
Available online: https://www.mdpi.com/2073-8994/13/5/873

4. “An Application of the Principle of Differential Subordination to Analytic Functions Involving Atangana–Baleanu Fractional Integral of Bessel Functions”
by Alina Alb Lupaş and Adriana Cătaş
Symmetry 2021, 13(6), 971; https://doi.org/10.3390/sym13060971
Available online: https://www.mdpi.com/2073-8994/13/6/971

5. “On Special Differential Subordinations Using Fractional Integral of Sălăgean and Ruscheweyh Operators”
by Alina Alb Lupaş and Georgia Irina Oros
Symmetry 2021, 13(9), 1553; https://doi.org/10.3390/sym13091553
Available online: https://www.mdpi.com/2073-8994/13/9/1553

6. “Applications of Banach Limit in Ulam Stability”
by Roman Badora, Janusz Brzdęk and Krzysztof Ciepliński
Symmetry 2021, 13(5), 841; https://doi.org/10.3390/sym13050841
Available online: https://www.mdpi.com/2073-8994/13/5/841

7. “Copulaesque Versions of the Skew-Normal and Skew-Student Distributions”
by Christopher Adcock
Symmetry 2021, 13(5), 815; https://doi.org/10.3390/sym13050815
Available online: https://www.mdpi.com/2073-8994/13/5/815

8. “Hermite Functions and Fourier Series”
by Enrico Celeghini, Manuel Gadella and Mariano A. del Olmo
Symmetry 2021, 13(5), 853; https://doi.org/10.3390/sym13050853
Available online: https://www.mdpi.com/2073-8994/13/5/853

9. “Symmetric Ground States for Doubly Nonlocal Equations with Mass Constraint”
by Silvia Cingolani, Marco Gallo and Kazunaga Tanaka
Symmetry 2021, 13(7), 1199; https://doi.org/10.3390/sym13071199
Available online: https://www.mdpi.com/2073-8994/13/7/1199

10. “Adjoint Operations in Twist-Products of Lattices”
by Ivan Chajda and Helmut Länger
Symmetry 2021, 13(2), 253; https://doi.org/10.3390/sym13020253
Available online: https://www.mdpi.com/2073-8994/13/2/253

11. “On the Relationship between Generalization and Robustness to Adversarial Examples”
by Anibal Pedraza, Oscar Deniz and Gloria Bueno
Symmetry 2021, 13(5), 817; https://doi.org/10.3390/sym13050817
Available online: https://www.mdpi.com/2073-8994/13/5/817

12. “Null Homology Groups and Stable Currents in Warped Product Submanifolds of Euclidean Spaces”
by Yanlin Li, Pişcoran Laurian-Ioan, Akram Ali and Ali H. Alkhaldi
Symmetry 2021, 13(9), 1587; https://doi.org/10.3390/sym13091587
Available online: https://www.mdpi.com/2073-8994/13/9/1587