I'm not really sure what Catholic Scholars have to say but I do know what the Bible states. John 1:4 states, "In Him was life, and the life was the light of men."
In other words, Jesus had life in Himself BEFORE His incarnation. Notice the use of the past tense in the verse. The Bible is clear according to Philippians 2:6-8 where we are told explicitly that the Son was the very form of God. The Greek here, "morphe" refers to the form that reveals or expresses the absolute nature of a thing.
Jesus humbled Himself by taking upon Himself the form (morphe" again) of a servant; the likeness of a man. He was not forced. He CHOSE to do so. That is why the Apostle Paul was using this as an example of humility according to the context starting at vs 1.
This power was given back to Him AFTER His resurrection, after He had accomplished His mission as a man. Regarding John 5:26, "Hath he given to the Son." This affirmation concerns not the Son as deity, but the office that the Son was commissioned to execute. "Gave" (edoken: hath given") is an aorist tense verb stating a historical fact.
The Apostle John confirms this at 1 John 1:1-2, "What was from the beginning, what we have heard, what we have seen with our eyes, what we beheld and our hands handled concerning the Word of Life--Vs2, "and the life was manifested and we have seen and bear witness and proclaim to you the eternal life, which was WITH the Father and was manifested to us."