user2681: What are the key differences between Ouroboros' Proof of Stake and Solana's Proof of History in aspects such as security, decentralization, functionality, efficiency (such as number of transactions per second) and energy use? Are there published papers or articles which compare the two?

user4023: I think it's too early to talk about security and efficiency of Solana's Proof-of-History consensus (it creates a historical record that proves that an event has occurred at a specific moment in time) which works with Proof-of-Stake mechanism and its additional layers (protocols) but some obvious things are written in a White Paper.
Here's an excerpt from white paper:

The combination of Proof-of-Replication and Proof-of-History provides a defense against forgery of the ledger with respect to time and storage. The protocol is analyzed on a 1 Gbps network, and this paper shows that throughput up to 710,000 transactions per second is possible with todays hardware. The average transaction fee in Solana blockchain is $0.00025.

As you know, when Hydra will be implemented in Cardano, the network can process up to 1,000,000 transactions per second. The average fee for a transaction in Cardano is approximately 0.15 ADA.
Both, Solana and Cardano support smart contracts. Both networks are energy-efficient (it's hard to say which one consumes less energy). Both are fully decentralized, and both are rapidly developing.
P.S.
And a few words about network's reliability. Today Bloomberg reported at 6:40 p.m.: Solana’s blockchain network has stopped processing transactions.

2681: <p>What are the key differences between Ouroboros' Proof of Stake and Solana's Proof of History in aspects such as security, decentralization, functionality, efficiency (such as number of transactions per second) and energy use? Are there published papers or articles which compare the two?</p>
 4023: <p>I think it's too early to talk about security and efficiency of Solana's <strong>Proof-of-History</strong> consensus (<em><strong>it creates a historical record that proves that an event has occurred at a specific moment in time</strong></em>) which works with Proof-of-Stake mechanism and its additional layers (protocols) but some obvious things are written in a <strong><a href="https://solana.com/solana-whitepaper.pdf" rel="nofollow noreferrer">White Paper</a></strong>.</p>
<p>Here's an excerpt from white paper:</p>
<blockquote>
<p>The combination of <em><strong>Proof-of-Replication</strong></em> and <em><strong>Proof-of-History</strong></em> provides a defense against forgery of the ledger with respect to time and storage. The protocol is analyzed on a 1 Gbps network, and this paper shows that throughput up to <em><strong>710,000 transactions</strong></em> per second is possible with todays hardware. The average transaction fee in Solana blockchain is $0.00025.</p>
</blockquote>
<p>As you know, when Hydra will be implemented in Cardano, the network can process up to <em><strong>1,000,000 transactions</strong></em> per second. The average fee for a transaction in Cardano is approximately 0.15 ADA.</p>
<p>Both, Solana and Cardano support smart contracts. Both networks are energy-efficient (it's hard to say which one consumes less energy). Both are fully decentralized, and both are rapidly developing.</p>
<p><strong>P.S.</strong></p>
<p>And a few words about network's reliability. <a href="https://www.bloomberg.com/news/articles/2021-09-14/blockchain-underlying-red-hot-crypto-solana-hits-processing-snag" rel="nofollow noreferrer">Today Bloomberg reported at 6:40 p.m.</a>: <em><strong>Solana’s blockchain network has stopped processing transactions</strong></em>.</p>
