VATICAN CITY -- On his first full day in office, Pope Benedict XVI dashed off a key invitation to tomorrow's installation ceremony: to Riccardo Di Segni, the chief rabbi of Rome.
Di Segni can't come -- tomorrow is the first day of Passover, which begins at sundown tonight -- but the invitation reinforced Benedict's position, which he outlined in several publications in recent years, that there is a special relationship between the Catholic Church and Judaism.
Academics and religious leaders interested in Catholic-Jewish relations are carefully watching Benedict's actions and scrutinizing his record in an effort to determine whether he will be as committed as his predecessor, John Paul II, to reversing millennia of Christian anti-Semitism. A Boston College research institute, the Center for Christian-Jewish Learning, has already assembled an Internet site cataloging Benedict's writings and utterances on Jews and Judaism.
The interest is intensified by Benedict's nationality -- he is the first German pope in nearly 1,000 years, and he lived through the period of the Nazis' mass murder of Jews. As a teenager he was a member of the Hitler Youth, then mandatory, and as a young man he served in an anti-aircraft unit, from which he deserted.
Multiple Jewish organizations, including the Anti-Defamation League, the American Jewish Committee, the Union of Reform Judaism, and the Jewish Community Relations Council of Greater Boston, issued statements immediately after Benedict's election Tuesday praising the new pope. Some have said he deserves credit for the actions of John Paul II to improve Catholic-Jewish ties, because he was such a close adviser and friend to his predecessor, others have noted that Benedict has visited Israel several times and had written positively about Jews.
But many say Benedict's record on this subject is somewhat thin, because the Congregation for the Doctrine of the Faith, the Vatican agency he had headed from 1981 until the April 2 death of John Paul II, is not in charge of Catholic-Jewish relations.
The new pope, the former Cardinal Joseph Ratzinger, faces several key challenges, scholars say. Among them is whether to canonize Pope Pius XII, who reigned during World War II and who has been criticized by some for not doing enough to speak out against Nazism.
''The general mood is one of cautious optimism -- I don't see great fears of any sort of reversal or retrenchment, but instead at least a feeling that things will be reinforced, even if there are not great leaps forward," said Philip A. Cunningham, executive director of the Boston College institute.
There are theological questions that remain unsettled, such as how the Catholic Church views the role Jesus plays in salvation for Jews. And, Cunningham said, it remains unknown whether Benedict will make the kinds of grand gestures, such as the visit to the Western Wall in Jerusalem, that John Paul made.
Benedict's record on relations between Catholicism and other Christian denominations, as well as his thoughts on relations with non-Christians, are the subject of considerable controversy because of his insistence on the supremacy of Catholicism and his objections to what he called Monday a ''dictatorship of relativism."
In 1986, he expressed skepticism about John Paul II's meeting with other religious leaders at Assisi, a gathering that was viewed as problematic by some conservatives because of the possibility that the side-by-side appearance of leaders might make it look like they were equals. He has written critically about the use of the phrase ''sister churches," insisting that Catholicism is the ''mother church." In a controversial 2000 document, ''Dominus Iesus," he referred to non-Christians as in a ''gravely deficient situation" when it comes to salvation.
But ''Dominus Iesus" did not specifically discuss Jews, and a year later Benedict suggested that Judaism is a special case among religions because of the preexisting covenant between God and the Jewish people.
''It must be noted that the relationship between Christianity and Judaism requires an altogether singular explanation," he wrote.
Benedict has also stepped into occasional controversy over his theological views on Jews and Judaism. In 1987, he was quoted in an Italian publication suggesting that Judaism finds its fulfillment in Christianity, and in 2000, he wrote, ''We wait for the instant in which Israel will say yes to Christ."
In 1988, because of the controversy over his remarks, and again in 2000, because of ''Dominus Iesus," Jewish leaders canceled planned meetings with Ratzinger.
Rabbi Michael Lerner, editor of the liberal Jewish magazine Tikkun, sent out an e-mail missive to a wide range of recipients this week calling Benedict's election ''a disaster for the world and for the Jews," in large part because of his conservative record on issues of sexuality and gender and theological dissent, but also in part because Lerner attributes the advancement of Pius XII's cause for sainthood to Benedict's ''tutelage."
Benedict has participated in multiple meetings with Jewish groups that went well, according to participants.
''I had a meeting with him a few years ago . . . and he seems like a very intelligent man, very faithful," Rabbi Di Segni said in an interview. ''We think the basis to continue dialogue exists."
Benedict also visited Israel before John Paul II did, and his visit was viewed as significant because of his job as the Vatican's top theologian.
Sergio Minerbi, a leading Israeli scholar of the Catholic Church who met Benedict in December 2003, said he disagrees with the new pope's views that salvation comes only through Jesus. But he applauded some of the pontiff's comments about the Holocaust.
''I admire his clarity, even if I cannot always share his views," Minerbi said.
Benedict's most direct statement outlining his views on Judaism came in an article he wrote in December 2000 for the official Vatican newspaper, L'Osservatore Romano. He wrote that ''as Christians, our dialogue with the Jews is situated on a different level than that in which we engage with other religions."
He also directly addressed the role of Christian anti-Semitism in the Holocaust.
''Down through the history of Christianity, already-strained relations deteriorated further, even giving birth in many cases to anti-Jewish attitudes, which throughout history have led to deplorable acts of violence," he wrote. ''Even if the most recent, loathsome experience of the Shoah [Holocaust] was perpetrated in the name of an anti-Christian ideology, which tried to strike the Christian faith at its Abrahamic roots in the people of Israel, it cannot be denied that a certain insufficient resistance to this atrocity on the part of Christians can be explained by an inherited anti-Judaism present in the hearts of not a few Christians."
''His writings have been very, very positive," said Rabbi James Rudin of the American Jewish Committee, who met Benedict in 1994. ''The only concern is whether he will give it the same attention and vigor that his predecessor did."
Jewish organizations say they are not concerned about Benedict's wartime activities, largely because he has spoken openly about his past.
''He was supportive of a group in Germany called Catholic Reconciliation, which sends Catholic young people to Israel to work on kibbutzim and to learn about Jewish life," said Abraham H. Foxman, national director of the Anti-Defamation League. ''You don't measure a person by two or three years in their teenage life, you measure it by a lifetime."
Charles A. Radin of the Globe staff contributed to this report from Tel Aviv, and Globe correspondent Sofia Celeste contributed from Rome.