There are several journals and publications that offer advanced topics in the UPSC Mathematics Optional subject. These resources can be extremely helpful for candidates preparing for the UPSC examination. Some of the notable publications in this field include:

1. "Mathematics Optional for UPSC" by R. S. Aggarwal: This publication covers a wide range of topics with a focus on the UPSC syllabus. It provides detailed explanations of concepts and includes numerous practice questions for self-assessment.

2. "Advanced Engineering Mathematics" by Erwin Kreyszig: This comprehensive textbook is widely used by engineering students and covers advanced topics in mathematics. It includes topics like linear algebra, complex analysis, partial differential equations, and numerical methods, which are relevant for the UPSC Mathematics Optional subject.

3. "Higher Engineering Mathematics" by B. S. Grewal: This book is another popular choice for candidates preparing for the UPSC Mathematics Optional subject. It covers a wide range of topics and provides clear explanations along with numerous practice problems.

4. "Introduction to Mathematical Statistics" by Robert V. Hogg, Joseph W. McKean, and Allen T. Craig: This book focuses on the statistical aspects of mathematics and provides a comprehensive introduction to the subject. It covers topics like probability theory, statistical inference, and hypothesis testing.

5. "Topology" by James R. Munkres: This book is recommended for candidates interested in advanced topics in topology. It covers the basics of point-set and algebraic topology, including topics like connectedness, compactness, and homotopy theory.

These publications can serve as valuable resources for candidates preparing for the UPSC Mathematics Optional subject. They provide in-depth coverage of advanced topics and offer ample practice opportunities. It is important for candidates to study from multiple sources and solve previous years' question papers to gain a comprehensive understanding of the subject.