The number of digital billboards featuring messages of peace being installed across Los Angeles as part of Yoko Ono's show opening on Saturday at the Broad Museum. It comes 57 years after Ono and husband John Lennon erected a billboard near the Chateau Marmont hotel on Sunset Boulevard with the message "War is Over! If you want It. Happy Christmas from John & Yoko."

London, New York and now Paris - Fresh from her work at the UK's National Gallery and Manhattan's Frick Collection, architect Annabelle Selldorf has been chosen to help transform the Louvre.

Her firm will work with STUDIOS Architecture Paris on the plan having beaten four other groups who submitted schemes to a jury including museum director Christophe Leribault.

Their win was announced today with a spokesperson saying their plan met the "challenges of visitor experience, clear pathways, simplicity, and greenery" while also "taking relevant security considerations into account".

The Paris museum has struggled for years under the weight of its own success with its around 9 million annual visitors often making for a difficult visitor experience.

Key aspects of the project, which could cost as much as $1.3 billion, include two new underground entrances and a "dedicated space for Leonardo Da Vinci's Mona Lisa, allowing the public to discover and contemplate it in satisfactory conditions".

Four painters have been shortlisted from more than 1,474 contenders for this year's National Portrait Gallery portrait award.

The London gallery will show 52 of the entries in a free exhibition from June 25 to October 7 with the winner announced two days before it opens.

Among the shortlist, chosen by a jury including designer Es Devlin, is Charlie and Magda by Michael Slusakowicz who was selected for the award in 2024 for another double portrait.

The winner receives around $46,800 with one of the artists chosen in this year and next year's exhibitions awarded a commission.

Architect Zaha Hadid will be remembered with a two-day symposium at London's Serpentine Galleries.

Hadid, who died in 2016, was the designer of the first Serpentine Pavilion which celebrates its 25th anniversary this year.

The latest pavilion, a temporary structure built every year in the grounds of the galleries, is designed by Mexican architects Isabel Abascal and Alessandro Arienzo and opens on June 6.

Serpentine artistic director Hans Ulrich Obrist said the pavilion, which will host an events program including live performances, film screenings and theatre, would be "a content machine".

He added: "We will also remember Zaha Hadid who gave us our motto that 'there should be no end to experimentation'."

1 - A new prize for contemporary painters has been launched in memory of Italian art critic Luca Beatrice who died last year. The Luca Beatrice Prize will be open to artists aged under 35 who work in Italy with the first award expected to be given out this year.

2 - A White House spokesman said Washington DC's National Portrait Gallery will host an exhibition of paintings of President Trump including work by speed painter Vanessa Horabuena. It comes as the gallery has replaced the text accompanying the president's image so it again refers to his two impeachment trials. A previous text was removed after the White House complained.

3 - Trouble down by the Thames where the chief executive of London's Southbank arts center, Misan Harriman, faces calls to resign over his social media comments including his support for the Green Party. A letter to the Times of London signed by a former BBC executive among others says his "daily interventions on social media" push "a divisive political agenda", but a spokesperson for the center said he had the right to "freedom of expression within the law".

4 - Amsterdam's Van Gogh Museum is celebrating after hosting its most successful show in a decade. Its exhibition Yellow. Beyond Van Gogh’s Color attracted a record 461,337 visitors through its doors.