Bernhard Riemann (1826–1866) is widely regarded as one of the leading mathematicians of the nineteenth century. He developed Riemannian geometry which is the basis for Einstein’s theory of gravitation. He also developed important theories relating to complex analysis, real analysis, number theory, and mathematical physics. This sleek iPhone case protects your phone from scratches, dust, oil, and dirt. It has a solid back and flexible sides that make it easy to take on and off, with precisely aligned port openings. • Hybrid Thermoplastic Polyurethane (TPU) and Polycarbonate (PC) material • Solid polycarbonate back • Flexible, see-through polyurethane sides • .5 mm raised bezel