Update README.md

README.md

 # 3OGC-projects
 
-Testing General Relativity with 3-OGC events:
+## Project: Testing Birefringence with 3-OGC events:
+
+#### Step1: 
+
+- [ ] Yifan: adding testing parity waveform into pycbc waveform plugin
+
+#### Step2: 
+
+- [ ] Alex: run pycbc_inference with parity violation waveform on 3-OGC
+
+References: 
+- [O1 and O2 testing birefringence/parity violation of GW](https://arxiv.org/pdf/2002.05668.pdf)
+- [LVC's testingGR paper with GWTC2](https://arxiv.org/abs/2010.14529)
+
+
+
+
+
+#### Other ideas: 
 - [ ] Testing Parity with IMRPhenomXPHM
 - [ ] Parametrized Post-Einstein with IMRPhenomXPHM
 - [ ] Multiple events' results correlation