NEW YORK — When Arkadiy Kantor created an online group to tell New York Jews about in-person social events during the COVID pandemic, he had no idea that it would be helping his friends find refuge from antisemitism just a few years later. But as a few dozen Jews aged 25-45 gathered for an informal picnic on a humid summer day in the city’s Central Park on Sunday, The Times of Israel found a meetup providing more than just companionship for a population still reeling from the aftermath of the October 7, 2023, Hamas attack on Israel. While New York...