CLASS LVDM modifies the CLASS code (ascl:1106.020) to incorporate the cosmological model of Lorentz invariance violation (LV) in gravity and dark matter. Compared to the usual CLASS code, it contains four new parameters: alpha, beta, and lambda characterize LV in the gravity sector
, and Y characterizes LV in the dark matter sector.
https://ui.adsabs.harvard.edu/abs/2012JCAP...10..057B , https://ui.adsabs.harvard.edu/abs/2015JCAP...03..016A