Here you will find a simulation of the risk of infection at big events. It shows, that these big events, as we know them so far, will probably not exist in the next few months.
Here is a simulation example of infection distribution at big events.
There are 4,000 visitors and one of them is spreading the virus. In that simulation we calculate with more available space, than usual at concerts and events. It is an simulated event, where visitors already are trying to keep their distance. Visitors are not immediately infected at contact, an attempt is made to simulate a more realistic infection. The visitors tend to move forward where the music is playing. The red point is the virus-spreading person, the yellow ones the infected. It is only a model, that shows the dangers and not a scientifically proven model.