Edgepedia

Topological spintronics

Topological spintronics is a branch of spintronics that uses topologically protected states, like topological insulator surface states and skyrmions, to move spin information with less dissipation.

Topological string theory

Topological string theory is a simplified, exactly computable version of string theory whose A-model and B-model on Calabi-Yau threefolds compute Gromov-Witten invariants and BPS black hole entropy.

Topological superconductivity is a superconducting state characterized by a topological invariant rather than a pairing gap, hosting protected surface states of Majorana fermions useful for quantum computing.

Topological superconductivity in van der Waals heterostructures

Topological superconductivity in van der Waals heterostructures is the creation of topological superconductivity by stacking atomically thin layers, such as ferromagnetic CrBr3 on superconducting NbSe2, pursued for topological quantum computing.

Topological superconductor

A topological superconductor is a superconducting phase, classified by a topological invariant of the bulk, that hosts Majorana zero modes at its boundaries, vortices, or defects.

Topological susceptibility

Topological susceptibility is a quantity in quantum chromodynamics, defined as the variance of the topological charge per unit volume, equal to the vacuum energy's curvature in the theta angle.

Topological valley kink states

Topological valley kink states are one-dimensional conducting channels along domain walls in bilayer graphene, first observed in 2015, each conducting carriers of one valley only.

Topological valley transport in photonic crystals

Topological valley transport in photonic crystals is the propagation of light along domain walls of valley photonic crystals, where valley-polarized edge states guide light around sharp bends without magnetic materials.

Topological vector space

A topological vector space (TVS) is a vector space with a topology making vector addition and scalar multiplication continuous, the basic setting of functional analysis beyond normed spaces.

Topology

Topology is the branch of mathematics that studies properties of figures and spaces preserved under homeomorphisms, with roots in Euler's 1736 Königsberg bridge work and Poincaré's founding of algebraic topology in 1895.

Sep 29, 2026

Topology control (wireless networks)

Topology control is a family of algorithms in wireless ad hoc and sensor networks that adjusts node transmission power to save energy while keeping the network connected.

Toponymy

Toponymy is the study of the origin and development of place names (toponyms), a branch of onomastics spanning macrotoponymy and microtoponymy, with geography, linguistics, history, and cartography as its pillars and UNGEGN standardizing names internationally.

Topos

A topos (plural: topoi or toposes) is a category behaving like a category of sheaves. Grothendieck toposes are sheaves on a site; elementary toposes, defined by Lawvere and Tierney, are axiomatized categories.

Topotecan

Topotecan, sold as Hycamtin, is a water-soluble, semi-synthetic derivative of camptothecin that inhibits topoisomerase I and is used as chemotherapy for ovarian, small-cell lung, and cervical cancer.

Oct 21, 2026

Topozero

Topozero (Топозеро; Finnish: Topasjärvi) is a large freshwater lake in northern Karelia, Russia, in the Kovda River basin and part of the Kumskoye Reservoir since 1966.

Toppan

Toppan, now TOPPAN Holdings Inc., is a Japanese diversified industrial group founded in Tokyo in 1900, spanning printing, packaging, security, and electronics, including the top-ranked merchant photomask business.

Oct 10, 2026

Toppan Printing

Toppan Printing (凸版印刷株式会社) is a Japanese printing and electronics group founded in Tokyo in 1900, now TOPPAN Holdings, with businesses in security printing, packaging, and photomasks.

Topper Guild

Topper Guild, American prank and stunt creator on TikTok and YouTube; 100M+ followers, 25B+ YouTube views, WME-represented, with the streaming series Topper Guild: Creator Essentials.

Topper Headon

Topper Headon (Nicholas Bowen Headon, born 1955), English drummer for the Clash 1977–1982; played on London Calling and Sandinista!, wrote and recorded "Rock the Casbah," dismissed for heroin addiction, later released the solo album Waking Up.

Topping out

Topping out, also called topping off, is the builders' rite marking a building's final beam at its highest point, a tradition traced to Scandinavia over 1,300 years ago.

Topps

Topps, the Brooklyn-founded chewing gum and trading card company behind the 1952 baseball card set, was acquired by Fanatics in 2022 for about $500 million and remains the flagship MLB card brand.

Oct 20, 2026

Topraichioi

Topraichioi (Babadag-Topraichioi), a small rectangular Roman burgus-type fortification in northern Dobruja, Romania: interior 38 × 14 m, wall 3.40 m thick, discovered 1978 and excavated 1979 by Opaiț and Zahariade.

Oct 20, 2026

Topramezone

Topramezone is a pyrazolone (Group 27) HPPD-inhibiting post-emergence herbicide, sold as Armezon, Clio, and Pylex, used mainly in maize and chickpea; registered in the US in 2005 but not approved in the EU since 2021.

Oct 21, 2026

Topsalysin

Topsalysin (PRX302, PORxin 302) is an experimental targeted prodrug injected into the prostate and activated by PSA to kill prostate cells, developed by Sophiris Bio for BPH symptoms.

Topshop

Topshop is a British womenswear fashion brand founded in 1964, a defining high-street retailer of the 1990s and 2000s that collapsed with Arcadia in 2020.

Sep 29, 2026

TOPSIS

TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) is a multi-criteria decision analysis method, introduced by Hwang and Yoon in 1981, that ranks alternatives by distance to ideal solutions.

Topsite

A topsite is a private, high-speed FTP server with gigabit bandwidth and tens to hundreds of terabytes of storage, used by warez scene release groups to distribute pirated media.

Topsoe

Topsoe, formerly Haldor Topsøe A/S, is a Danish engineering company founded in 1940 that develops catalysts and process technologies for the chemical, refining, and energy-transition industries.

Topsoil

Topsoil, also known as surface soil, is the uppermost and most fertile soil layer, holding most organic matter and plant roots, and the part most lost to erosion.