I found this interesting.
"Starting in the summer of 2028, travelers shall be able to take a direct train from Berlin to the Norwegian capital Oslo, via Hamburg, the Danish capital Copenhagen, and Malmö and Gothenburg in Sweden. “We’re connecting three capitals by rail,” Michael Peterson, Deutsche Bahn’s executive in charge of long-distance rail, told Funke newspapers. For the direct connection, Deutsche Bahn will collaborate with the national railways of Norway and Denmark.
According to Deutsche Bahn, the journey is expected to take 14 to 15 hours. The route will be approximately 1,000 kilometers long, making it one of the longest in Europe. Two pairs of trains will operate the route daily. The new ICE L will be used on the new connection. The direct connection is one of ten pilot projects by the European Commission aimed at expanding cross-border transport."
Source: https://www.n-tv.de/wirtschaft/Deutsche-Bahn-plant-Direktverbindung-nach-Oslo-id30803866.html