Citizens from some countries outside the European Union need a visa to visit Denmark.
On New to Denmark you can see which citizens need a visa. The information on the homepage linked to should be trustworthy, but it is recommended to double check with your local Danish representation.
For the visa application you need an invitation form named VU3 which can be found at the above link. Please fill in your details and mail it to ice2017@dtu.dk and we will return it with a signature for use at the local Danish representation near you.
Authorities claim to be able to make visa in 15 days in simple cases, but they may spend 30 days when additional information is needed. In any case, we recommend you get the process started as soon as possible.