Does the Qalqalah of the letter "Kaf" in the opening Takbir invalidate the prayer?

The opening takbir (Allahu Akbar) is a pillar of prayer, without which the prayer is invalid. What suffices in it is "Allahu Akbar." The takbir is not valid if its meaning is altered by a grammatical error (laḥn), such as adding an interrogative hamza to "Allahu" (making it "Aallahu?") or elongating "Akbar" to become "Aakbar" (which is the plural of kabar, meaning drum). However, a slight error that does not change the meaning, such as the quivering of the letter "kaf" in "Akbar" or the doubling of the "ra," does not harm or invalidate the prayer.