How to pronounce 调 in 同调代数? Certainly 同调代数 means the mathematical subject of homological algebra.  But different sources disagree as to whether the first two characters in that sense of the term are pronounced tóngtiáo or tóngdiào.

In fact I have mostly seen the characters with no pinyin, including on zh.wikipedia, and I have not spoken with Chinese mathematicians about it.  The term is not in my paper dictionaries.  Google translate and perapera both give tóngdiào.  But Wenlin (using the ABC dictionary) gives tóngtiáo for "homology" without specifying the mathematical sense. 

Which is it?  Since seeing the comments below, I take the Baidu entry with pinyin as authoritative for tóngdiào.
同调 pronounces as: tóng diào, see reference. 

(1) [same tone]∶音调相同

(2) [person with same common purpose or taste]∶比喻志趣或主张相同的人