We will have the 6th online colloquium “Extreme Universe Colloquium” on May 23rd (Mon) 16:00 (JST). The speaker is Prof. Keiji Saito (Keio University). For details, please refer to the poster. If you have not registered yet, please register at our online event website at least three days prior to the colloquium. (It is not necessary to register again if you have done it already.)