UPPER WEST SIDE — A pair of rare million-dollar musical instruments has divided a family full of math and science geniuses.
The 90-year-old daughter of renowned NYU mathematician Richard Courant has accused her musician sister of hogging their late mother's pricey, 200-year-old Italian viola and German violin which had been loaned to her.
Dr. Gertrude Courant Moser, co-executor of her mother Nina Courant's estate, says in court papers filed earlier this year that her younger sister, Lori Courant Lax, 85, refuses to return the instruments so they can be sold or fairly divided among the family.
Moser, a marine biologist and the widow of math genius Jurgen Moser, claims that her mother, a professional musician, had a history of loaning her instruments to family and friends to use and enjoy.
"[Nina Courant] never made gifts of the instruments to anyone, including family members," she said in a petition demanding the instruments' return to the estate.
The petition claims that before Nina Courant's death in 1991, she lent them to Lax, who lives with her husband, yet another math whiz Peter Lax, on Central Park West.
Moser said she expected her sister to return them eventually. But in February 2012, Lax told the wife of her brother, accelerator physicist Ernest Courant, that she planned to bequeath the instruments to her children in a will, the filing says.
Ernest, also a co-executor of his mother's estate, and Moser told Lax that the estate owned the instruments.
Moser's lawyer also wrote a letter to Lax in August 2012 encouraging her to resolve the squabble at an upcoming family get-together at Loon Lake in upstate New York.
"I hope you are able to summon the strength to listen to and discuss this with those who love you and do not want this anxiety to continue," the lawyer wrote. "It must be painful for you and it certainly is for your Courant family."
When the siblings didn't reach a harmonious agreement, Moser filed the petition in February in Westchester Surrogate's Court. She stated that after their mother's death, the four siblings struck a deal on how to split all her belongings except for a few items, including the instruments.
Moser wants the violin and viola — which are valued at more than $1 million — returned so they can be sold.
In a legal response last month, Lax denied the allegations and demanded that the court throw out the petition, arguing that the statue of limitations had long since expired.
Lax's lawyer, Robert Boneberg, declined to comment on the case.
"She expects to prevail and I think we'll let our filings articulate her position," he told DNAinfo New York.
Moser's lawyer did not respond to requests for comment.
Nina Courant obtained the violin — which dates back to about 1800 — from a family friend in Germany, the petition says. Her husband, Richard Courant, bought her the viola, which dates to around 1790.
A German emigre, Richard Courant began working at NYU in 1936. He died in 1972. The university's Courant Institute of Mathematical Studies is named after him.