Question: What was the birth name of the man that created "Fourth World"?

full_context: Document 1: Deep Six (DC Comics): The Deep Six are a fictional team of half-humanoid comic book villains created by Jack Kirby as part of the Jack Kirby's Fourth World set of DC Comics titles. They first appeared in "The New Gods" #2 (April–May 1971).
Document 2: Urgrund (comics): In the Fourth World storyline of DC superhero comics, Urgrund was an ancient planet A foreign object collided With the planet that caused it to break Apart and created two planets from it, and these are the names of the planets : the "majestic, sun-soaked" New Genesis, inhabited by the New Gods and ruled by the Highfather, and Apokolips with its "mammoth fire pits and machinery", ruled by the evil Darkseid and his right hand evil man Steppenwolf and inhabited by his minions and the downtrodden population beneath them.
Document 3: Jack Burnley: Jack Burnley (January 11, 1911 – December 19, 2006) was the pen name of Hardin J. Burnley, an American comic book artist and illustrator. Burnley was the first artist, after co-creator Joe Shuster, to draw Superman in comic books.
Document 4: Rip Kirby: Rip Kirby is a comic strip featuring the adventures of the eponymous lead character, a private detective created by Alex Raymond in 1946. Displaying the talents of more than a dozen writers and illustrators, the strip had a run spanning five decades.
Document 5: Goodman, Lieber, Kurtzberg &amp; Holliway: Goodman, Lieber, Kurtzberg & Holliway is a fictional law firm appearing in American comic books published by Marvel Comics. The firm is commonly depicted in the pages of the "She-Hulk" comic books - named after Marvel Founders Martin Goodman, Stan Lee, under his birth name Stanley Lieber, and Jack Kirby, using his birth name Jacob Kurtzberg. Created by Dan Slott, senior GLK&H law partner Holden Holliway first appeared in "She-Hulk" #1 (May 2004), where he hired the titular heroine to be a lawyer for his law firm, but as Jennifer Walters.
Document 6: Fourth World (comics): "Fourth World" is a storyline told through a metaseries of interconnecting comic book titles written and drawn by Jack Kirby, and published by DC Comics from 1970 to 1973. Although they were not marketed under this title until the August–September 1971 issues of New Gods and Forever People, the term "Fourth World" or "Jack Kirby's Fourth World" has gained usage in the years since.
Document 7: East of West: East of West is a monthly comic book series published by Image Comics which debuted in March 2013. Created by writer Jonathan Hickman and artist Nick Dragotta, the book is a science fiction Western set in a dystopian version of the United States whose fate rests with the Four Horsemen of the Apocalypse.
Document 8: Mort Künstler: Mort Künstler (born August 28, 1927) is an American artist known for his illustrative paintings of historical events, especially of the American Civil War. He was a child prodigy, who, with encouragement from his parents, became a skilled artist by the time he was twelve. Today he is considered the "best-known and most respected historical artist in the country."
Document 9: Mortal Kombat (comics): The "Mortal Kombat" comic books series included the official "Mortal Kombat" comics by Midway and a licensed adaptation series by Malibu Comics that was published in 1994-1995. There are thus two different lineups of "Mortal Kombat" comics: the tie-ins published by Midway (some of them made by "Mortal Kombat" co-creator John Tobias) and DC Comics that closely followed the storyline of the games, and the Malibu series, which took a few liberties with the source material.
Document 10: John Romita Sr.: John V. Romita Sr., often credited as simply John Romita ( ; born January 24, 1930), is an American comic-book artist best known for his work on Marvel Comics' "The Amazing Spider-Man" and for co-creating the character The Punisher. He was inducted into the Will Eisner Comic Book Hall of Fame in 2002.
Document 11: Joe Shuster: Joseph "Joe" Shuster ( ; July 10, 1914 – July 30, 1992) was a Canadian-American comic book artist best known for co-creating the DC Comics character Superman, with writer Jerry Siegel, in "Action Comics" #1 (cover-dated June 1938).
Document 12: Superman/Fantastic Four: Superman/Fantastic Four, subtitled "The Infinite Destruction," is an intercompany comic book jointly published by DC Comics and Marvel Comics in July 1999. The tale unites DC's first superhero Superman and Marvel's first superhero team, the Fantastic Four—pitting them against the Cyborg Superman (who gained notoriety in 1993 during DC's "Reign of the Supermen" story arc) and the longtime FF foe Galactus.
Document 13: Jack Kirby: Jack Kirby ( ; born Jacob Kurtzberg ; August 28, 1917 – February 6, 1994) was an American comic book artist, writer, and editor, widely regarded as one of the medium's major innovators and one of its most prolific and influential creators.
Document 14: Serenity (comics): Several comic book stories have been released under the Serenity title, set in the fictional universe created for Joss Whedon's "Firefly" television series and "Serenity" film, and which are considered canon. As of 2014, eight "Serenity" stories have been published. Written by Joss Whedon and Brett Matthews, and illustrated by Will Conrad, the first miniseries, "Those Left Behind", was created as a bridge between the events of the series and film. "Those Left Behind" was popular: the first issue was the highest-selling comic published by Dark Horse Comics since the release of "Buffy Season 8" in 2007, while the trade paperback is still one of the highest ranking items by sale quantity from that company. In early 2008, a second miniseries was released. Titled "Better Days", it was set before "Those Left Behind", with the storyline based around a heist that went in the characters' favor. In addition to the miniseries, a one-shot comic written by Jim Krueger and titled "The Other Half" was released in the August 2008 issue of "Dark Horse Presents".
Document 15: Star Trek: Year Four: Star Trek: Year Four is the first of two "Star Trek" comic book mini-series released by IDW Publishing. The first issue was released on July 26th, 2007 with a cover price of $3.99. It featured three variant covers. The series picked up where the original television series left off and told stories set in the fourth year of the original five-year mission.
ground_truth: Jacob Kurtzberg