Complex sentence: Various speculative proposals to get rid of this discrepancy have been suggested (for example, an argument based on quasinormal modes), but as of today, no justification or alternative calculation of this constant exists.
Split into simpler sentences: Various speculative proposals to get rid of this discrepancy have been suggested: for example, an argument based on quasinormal modes. As of today, no justification or alternative calculation of this constant exists.