[martin-dev] add arxiv link

README.md

@@ -29,7 +29,7 @@ This repo is a public release of [**Fast Spatial Memory with Elastic Test-Time T
 ### Model Sources [optional]
 
 - **Repository:** [https://github.com/Mars-tin/fast-spatial-mem]
-- **Paper:** [To be updated]
+- **Paper:** [https://arxiv.org/abs/2604.07350]
 - **Homepage:** [https://fast-spatial-mem.github.io/]
 
 ## Performance Documentations