Screen 11

It's Morse Code
The screen starts with the famous superman clip, but instead of saying "Superman", the narrator says "Morse Code".

The Shrek Puzzle
The screen shows the opening scene from the movie Shrek, mirrored and very distorted. And the first thing that shows up on the screen is: Those are timestamps for the Shrek movie and are from a scene where Shrek talks about onions.
 * 00:27:00
 * 00:27:30

This section also has morse codes assigned to pieces of text, these texts and morses translated, respectively, are: These numbers are actually Pi’s decimal numbers: So ordering the text strings based on the sequence of the Pi decimals results in: Adding .onion to this text, as the Shrek hint suggested, and entering it on the TOR browser opens up a website with a username and password request.
 * lyaamqd - 0628620899
 * o3xooob - 1415926535
 * 7pb724b - 2643383279
 * q3lqrgz - 5028841971
 * 6jfbtzz - 5820974944
 * jcmb5f2 - 5923078164
 * a6z2lua - 6939937510
 * fqdpbgp - 8979323846
 * 3.14159265358979323846264338327950288419716939937510 58209749445923078164062862089986280348253421170679
 * o3xooobfqdpbgp7pb724bq3lqrgza6z2lua6jfbtzzjcmb5f2lyaamq

The Mathematicians
This part of the puzzle starts with an overlay of mathematic equations and a distorted voice saying: And then, a piano song starts playing on the background, this song was the Fibonacci sequence numbers converted into notes.
 * “Standard naming conventions apply. Lowercase. Town_Year”

This section continues with 8 sets of a map of a country, a symbol of a city in this country and something related to a mathematician born in this city. After each of these sets, the same voice from earlier says "DIRECTORY". The sets, in order, are: Then, ending this section, the voice says "THIS FONT IS" and a text written with the font DejaVu shows up.
 * Kingdom of Hanover Map - Coat of Arms of Braunschweig - Gaussian Blur from Carl Gauss
 * Russian Empire Map - Coat of Arms of Saint Petersburg - Text from Georg Cantor
 * Italian States Map - Coat of Arms of Pavia - Cardan Joint from Girolamo Cardano
 * USSR Map - Coat of Arms of Saint Petersburg -Picture of Grigori Yakovlevich Perelman
 * England Map - Coat of Arms of Liverpool - Game of Life from John Horton Conway
 * Austria-Hungary Map - Coat of Arms of Budapest - Picture of Paul Erdos
 * Kingdom of France Map - Coat of Arms of La Haye en Touraine -Picture of René Descartes
 * Madras Presidency Map - Tamil Nadu Symbol -Ramanujan’s Constant from Srinivāsa Aiyangār Rāmānujan

Just Do It
Ending the loop, the famous video from Shia LaBeouf giving the "Just Do It" motivational speech plays on the screen and in front of it, on low opacity, a video of someone tearing paper with a ruler is shown.

The TOR Website
The name of the mathematician should be used as the username and the town and year where he was born as the password, in this format:
 * username: c.gauss < initial.surname

Doing that for every mathematician showed previously resulted in 8 different .exe files, that needed to be ordered by the constant of e, the numbers could be found on the URL of each mathematician directory.
 * password: braunschweig_1777 < town_year (as the voice hinted)

The .EXE files
Each .exe gave an error upon execution, all of the errors looked the same, except for a small part that could be UP or DN. Inspecting the .exe code, revealed that the errors where programmed, and that there were 3 different strings of errors, the middle one should be decrypted in HEX code. After all of the 8 strings are decrypted, it's necessary to remove the zeros, as the hint of Ascii 157 (a slashed zero) given on day 5 suggested.

All of the strings, in the correct order, without the zeros, and with respective UP and DN marking:

UP - T1EZ FTF L1T

DN - 2X 2L2

UP -7A TZ7 F

DN - VXV F2 WPT 7

UP -F FET

DN - ZFA Y

UP - AT YZL 17A LT N EY

DN - PE 27 ZTEZ L2 2ZZ VEF Y

The Answer
Using the hint from the beginning, we should use the strings of text seen previously, with the DejaVu font, and for the ones marked with UP, it's necessary to separate only the top portion of the text, and for the ones with DN, the bottom portion of the text. After doing that, what's left is a morse code: That translates to "YOU DO NOT HAHE TO BE AFRAID ANYMORE", and as "HAHE" is just a mistype of the word "HAVE", we have the sentence: "You do not have to be afraid anymore".

Therefore our answer is you_do_not_have_to_be_afraid_anymore.