Oslo can be easily reached by air from all over the world. There are many direct flights to and from main airport hubs, but it is also easy to connect via major airports in Europe.
The campus is centrally located in Oslo with many hotels in the vicinity. The campus is easy to reach via tram, bus or metro for those that choose hotels a bit further away.
Most participants will arrive at the Gardemoen airport and most convenient transport to the center is the airport express which departures every 10th minute. The ordinary railway is a cheaper alternative but runs less frequent and is usually more crowded. Ticket machines for both services can be found on the ground floor.
Ticket for the #ruter tram, bus and metro can be purchased online, by installing an app, or at kiosks on major stations. If you plan to use the tram/metro/bus regularly you should consider a 7 day pass. There are controls very often and not a good idea to forget to purchase a ticket (fee of 90 euro).
If you purchase a single ticket for 4 zones it is also valid for the regular train to or from the airport (but not valid for the express). The benefit of purchasing a ticket to/from the airport from #ruter is that it allows you a transfer between the train and the tram/metro/bus.
Norwegians do not need cash very often and as a visitor you are not likely to need any cash at all. All stores, restaurants and services will accept cards. There are some exceptions such as very local businesses. Just ask in advance if you are in doubt.