activity
20212026
collaborators

7 papers

math.AP2026

On rigidity of stationary black holes under a nontrapping assumption

Alexandru F. Radu

We prove that a smooth, regular, asymptotically flat stationary vacuum black hole has a nonextremal Kerr exterior if no null geodesic orthogonal to its stationary Killing field is…

math.AP2026

Non-unique singular solutions for KP and modified KP equations on and

Alexandru F. Radu

We construct infinitely many weak singular solutions with zero initial data and compact time support for third- and fifth-order KP-I, KP-II, and their modified counterparts on $\ma…

math.AP2026

Non-unique solutions to the periodic gKdV equation

Nicholas Gismondi, Kunyi, Ma +2

In this paper we utilize a convex integration scheme to construct non-trivial weak solutions to the -generalized KdV equation which lie in $$ \bigcap_{ε> 0} C_t^0 L_x^{k-ε}([0,1…

math.AP2026

Uniqueness in Lorentz Spaces of the 2d Navier-Stokes equation

Alexandru F. Radu

We study uniqueness of mild solutions to the two--dimensional incompressible Navier-Stokes equations on the torus in borderline spatial classes. While Lorentz-space methods yield u…

math.AP2025

Intermittent solutions of the stationary 2D surface quasi-geostrophic equation

Nicholas Gismondi, Alexandru F. Radu

In this paper we construct non-trivial solutions to the stationary dissipative surface quasi-geostrophic equation on the two dimensional torus which lie strictly below the critical…

math.RT2022

On the monomial algebra associated to the monomial characters of a finite group

Mircea Cimpoeas, Alexandru F. Radu

Given a finite group , we study the monomial algebra , generated by the monomial characters of . In particular, we note that the integral closure of is contained i…