This is the second book in the Nulapeiron Sequence by John Meaney. The protagonist is still Tom Corcorigan, who in the first novel rose from slavery to royalty in part because of his "logosophical" (read "mathematical") skills, but math does not play as important a role in this novel as it did in the first.
In my review of Paradox, I proposed measuring the mathematical content of a novel by the number of pages I "dogear" as containing a math reference. If this is your measure, then the mathematical content dropped to 19 dog ears. Not only has the number of references dropped from the first novel, but their significance to the plot has also decreased. Many of these are just throwaway lines that mention "fractals" or something vaguely mathematical. In the end, however, the solution to the dilemma facing the planet is addressed through the mathematical research of Tom's colleague, Avernon.
One mathematical reference, in particular, demands my attention. In one part we read:
(quoted from Context)
Are mathematical minds made vulnerable by their abilities, or is it that, seeing so deeply, the arbitrary and ephemeral nature of consensual reality becomes too fliimsy to hold on to?
Ro thought of Cantor: preiods of deep insight into the nature of infinte sets, invariably followed by incarceration  amid black depression  in the Nerveninstitut von Halle.
Are thought, then, so fragile?
Nash's Nobel Prizewinning one page paper, founding the concept of gametheoretical equilibria, highlighting the nuclear madness of Mutual Assured Destruction  the product of a mind about to be torn apart by schizophrenia.
Or is infinite truth so dangerous?

I must say that despite the popularity of the idea that there is a connection between mathematical greatness and insanity, I remain quite skeptical. Of course, people can name examples of insane mathematicians...but this is not any sort of evidence at all. Certainly, there is not a profession in existence for which every practitioner remains perfectly sane throughout their lives. Some people are going to have mental difficulties, and that some of those people are mathematicians does not prove any link. And of course, for every insane mathematician you can name, there are hundreds of others who had no such problems. But, the stereotype remains. I wonder if anyone can provide me with data either supporting or disproving the hypothesis that there is a real connection here? If you know of some, please write to me. 